April ’21 – NZ blogs sitemeter ranking


Image credit:
Blog Writing For Business NZ

I notice a few regulars no longer allow public access to the site counters. This may happen accidentally when the blog format is altered. If your blog is unexpectedly missing or the numbers seem very low please check this out. After correcting send me the URL for your site meter and I can correct the information in the database.

Similarly, if your blog data in this list seems out of whack, please check your site meter. Usually, the problem is that for some reason your site meter is no longer working.

Sitemeter is no longer working so the total number of NZ blogs in this list has been drastically reduced. I recommend anyone with Sitemeter consider transferring to one of the other meters. See  NZ Blog Rankings FAQ.

This list is compiled automatically from the data in the various site meters used. If you feel the data in this list is wrong could you check to make sure the problem is not with your own site meter? I am of course happy to correct any mistakes that occur in the automatic transfer of data to this list but cannot be responsible for the site meters themselves. They do play up.

Every month I get queries from people wanting their own blog included. I encourage and am happy to respond to queries but have prepared a list of frequently asked questions (FAQs) people can check out. Have a look at NZ Blog Rankings FAQ. This is particularly helpful to those wondering how to set up sitemeters. Please note, the system is automatic and relies on blogs having sitemeters which allow public access to the stats.

Here are the rankings of New Zealand blogs with publicly available statistics for April 2021. Ranking is by visit numbers. I have listed the blogs in the table below, together with monthly visits and page view numbers. Meanwhile, I am still keen to hear of any other blogs with publicly available sitemeter or visitor stats that I have missed. Contact me if you know of any or wish help adding publicly available stats to your bog.

You can see data for previous months at Blog Ranks

Subscribe to NZ Blog Rankings Subscribe to NZ blog rankings by Email Find out how to get Subscription & email updates

Rank Blog Visits/month Page Views/month

1

The Daily Blog

62558

267659

2

Liturgy

34006

40649

3

13th Floor

21768

25129

4

Tikorangi: The Jury Garden

15043

16766

5

Sacraparental

11595

13116

6

Bill Bennett

9320

9924

7

Cycling in Christchurch

8037

9059

8

Creative Maths

7790

9130

9

SciBlogs

7520

17274

10

Homepaddock

7406

8122

11

Free range statistics

6924

9312

12

Music of sound

4531

5942

13

Lost in silver fern

4029

6089

14

Offsetting behaviour

3726

4252

15

Nom Nom Panda

3437

3702

16

Woodleigh Nursery

2575

4645

17

Jontynz

2505

2888

18

The Meaning of Trees

2151

3372

19

Talking Auckland

1411

1578

20

No Minister

1328

1574

21

The Global Couple

1267

1447

22

Fields of Blood

1202

1387

23

Anglican down under

1197

1535

24

The Woolshed Wargamer

1164

2079

25

Economics New Zealand

1143

1165

26

Open Parachute

1077

1324

27

Reading the maps

997

1278

28

A communist at large

967

1213

29

Sarah the Gardener

929

1230

30

Muffin-Mum

889

937

31

Off the couch

740

917

32

Hot Topic

677

866

33

Rodney’s Aviation Ramblings

594

749

34

TVHE

572

649

35

Pdubyah – a life just as ordinary

470

513

36

Home education Foundation

448

526

37

Vomkrieg

382

495

38

Aughts and Oughtisms

367

468

39

Stratford Aerodrome

359

498

40

Climate Justice Taranaki

346

432

41

Kiwi Cakes

325

378

42

Fun with Allergy Kids

306

425

43

AmeriNZ

301

495

44

Communication, Church, Society

277

330

45

Tales from a Caffeinated Weka

264

271

46

Quote Unquote

263

285

47

Perissodactyla

242

267

48

Cambridge NZ

241

263

49

Mrs Cake

214

271

50

Sparrowhawk/Karearea

195

239

51

New Zealand Conservative

175

195

52

Media Sport and Other Rantings

156

159

53

Creative Voice#

144

275

54

Social Media & the 2014 Election

125

150

55

The Catalyst

121

150

56

AnneKcam

112

141

57

Mountains of Our Minds#

111

152

58

Tauranga Blog

104

107

59

Save our Schools NZ

101

105

60

Eye on the ICR

100

122

61

Ideologically impure

89

111

62

Room One @ Auroa School

85

117

63

Room 5 @ Melville Intermediate School

78

92

64

Right Reason

76

76

65

Unity Blog

73

102

65

Undeniably Atheist

73

83

67

My thinks

64

68

67

Glennis’s Blog Page#

64

75

69

Aotearoa: A wider perspective

62

66

70

Exile in New zealand

60

81

71

John Macilree’s Weblog#

58

64

72

Put ’em all on an island

51

58

73

goNZo Freakpower Brains Trust

50

51

73

Anne Free Spirit

50

74

75

Quietly in the backgroud

44

47

76

Family integrity

39

39

76

Wokarella

39

56

78

Glenview 9

30

30

79

ElephaNZa

29

31

80

Wellington Chic

28

28

81

Software development and stuff

24

25

82

Keeping Stock

22

22

82

University of Otago, Law Library Blog

22

32

84

James McKerrow – Surveyor 1834-1919#

20

22

85

MartinIsti Blog

19

21

85

Nelsonian’s life

19

20

87

Dad4justice

16

16

88

John Macilree’s Blog

15

15

88

Get Out Gertrude!

15

21

88

kiwiincanberra

15

15

88

The Official Ebenezer Teichelmann Blog#

15

15

92

kiwi simplexity

14

14

93

Look, Think, Make

12

12

94

Cut your hair

11

11

94

Warrington Taylor#

11

11

96

Carolyn’s blog

10

11

96

Samuel Dennis

10

10

96

bread and pomegranates

10

17

96

Chris Jillet – Mountaineer#

10

10

100

Helen Heath

9

9

100

Four seasons in one

9

9

102

MandM

8

8

102

Journey to a mini me

8

8

104

The Well read Kitty

7

8

104

New Zealand female Firefighter calendar

7

7

104

Room 24, 2012

7

7

107

ah! New Year’s Resolution

6

6

108

Taradale Blog#

5

5

109

New Zealand Indian Fine Arts Society

4

4

109

Socialist Aotearoa

4

4

111

High voltage learning during the Christchurch earthquakes

3

3

112

SmallTorque

2

2

112

Utopia – you are standing in it

2

3

114

Bob McKerrow – Wayfarer

1

1

114

The Little Waaagh! That Could

1

1

114

Misses Mac

1

1

Hip fractures in the elderly and fluoride – contradictory evidence

Room for cherry-picking to confirm a bias. Separate Swedish studies report that fluoride can either prevent or promote the risk of hip fracture in the elderly. Image credit: Are hip fracture patients treated quickly enough?

Anti-fluoride activists are promoting a recent study linking fluoride intake and bone fractures. No surprise there. But they are cherry-picking a single study to support their agenda and scientifically literate people should see the wider picture and not ignore other studies which, on the whole,  convey a different story. This issue illustrates problems with epidemiological studies producing variable results and shows why people should avoid cherry-picking and look at the full range of studies in a field.

Here I consider just two studies on fluoride intake and bone fracture which produced different conclusions. Both studies involved people from Sweden where the natural fluoride levels in drinking water vary across the country.

Drinking water fluoride may protect against hip fractures

First a study from 2013:

Näsman, P., Ekstrand, J., Granath, F., Ekbom, A., & Fored, C. M. (2013). Estimated drinking water fluoride exposure and risk of hip fracture: A cohort study. Journal of Dental Research, 92(11), 1029–1034.

The main findings are illustrated in the figure showing the calculated Hazard Ratios for people of different ages living in areas of Sweden with “very low” (less than 0.3 mg/L), “low” (0.3 – 0.69 mg/L), “medium” (0.7 -1.49 mg/L) or “High” (greater than 1.5 mg/L) fluoride levels in the drinking water. The Hazard Ratio in the figure below is a measure of the number of hip fractures at these levels compared with the number of hip fractures at “Very low” fluoride concentration. The bars represent the 95% confidence intervals. The Hazard Ratios for the “very low” group are 1.0 and Hazard Ratios statistically significantly different to 1 (no effect) are coloured red.

Considering all people there is no statistically significant increase in the number of hip fractures for any level of water fluoride concentration compared with the “very low” levels. The number of hip fractures experienced by people in the two lower age groups (less than 70 years and 70 – 80 years) was significantly lower at higher water fluoride concentrations than at the “very low” concentrations. The authors say:

this “suggests a protective effect of fluoride among the younger (age younger than 80 years): however, the majority of fractures occurred above the age of 80 years (median age at time of fracture, 82.0).”

So a study suggested that the fluoride in Swedish drinking water does not encourage bone fractures and may actually protect against them in the lower age groups.

Fluoride may encourage hip fractures

Now a study from 2021 – the one anti-fluoride activists are promoting (for obvious reasons):

Helte, E., Vargas, C. D., Kippler, M., Wolk, A., Michaëlsson, K., & Åkesson, A. (2021). Fluoride in Drinking Water , Diet , and Urine in Relation to Bone Mineral Density and Fracture Incidence in Postmenopausal Women. Environmental Health Perspectives, 129(April).

Unlike Näsman et al (2013) which used drinking water fluoride concentrations as a measure of fluoride exposure, Helte et al (2021) used urinary fluoride and estimated dietary fluoride intake as measures of fluoride exposure. The Hazard Ratios were calculated from the number of hip fractures in the Tertile 2 groups (0.88 – 1.30 mg/g urinary fluoride or 1.74 – 2.41 mg/day dietary fluoride intake) and Tertile 3 groups (1.30 – 116.51 mg/g urinary fluoride or 2.41 – 11.16 mg/day dietary fluoride intake) compared with hip fractures in the tertile 1 groups (0.14 – 0.88 mg/g urinary fluoride or 0.26 – 1.74 mg/day dietary fluoride intake).

Note: The urinary fluoride units of mg/g represent mg of urinary F/g urinary creatinine. Creatinine levels were used to correct the spot values for dilution.

The Hazard Ratios that statistically significantly different to 1 (no effect) are coloured red in the figure below.

A bit complicated I know, but what the figure shows is no statistically significant increase in hip fracture numbers for the tertile 2 groups compared with the lower F intake tertile one group. But a significant increase in fracture numbers for the tertile 3 groups except for the women exposed to constant water fluoride concentrations since 1982 in the dietary F group.

Hertle et al (2021) also considered other types of fracture. There were no statistically significant increases in fractures in the upper tertiles for either the “all fractures” or “major osteoporotic fractures” classes.

So, a bit of a mixed bag but this paper is currently being promoted by anti-fluoride activists as evidence of a harmful result from community water fluoridation (CWF).

Critically assessing the evidence for bone fractures

It is easy to see why supporters of CWF may cite Näsman et al (2013) as evidence for lack of harm and opponents may cite Helte et al (2021) as evidence of harm from CWF. But neither approach is really scientific. The methodological differences and choice of factors considered can easily explain variable results. One should critically and rationally assess both of these papers, together with the many other papers reporting similar studies, before coming to any conclusion.

On balance, the published studies probably support the findings of Näsman et al (2013) and not Helte et al (2021). In fact, a systematic review and meta-analysis published in 2015 concluded that chronic exposure to fluoride in drinking water was not associated with a significant increase in hip fracture risk. The citation for this review is:

Yin, X.-H., Huang, G.-L., Lin, D.-R., Wan, C.-C., Wang, Y.-D., Song, J.-K., & Xu, P. (2015). Exposure to Fluoride in Drinking Water and Hip Fracture Risk: A Meta-Analysis of Observational Studies. PLOS ONE, 10(5), e0126488. 

It’s worth reproducing one of the figures from that review because it illustrates how epidemiological studies may, individually, support a claim of harm but when considered as a whole these studies do not support the claim. The figure below shows the range of Hazard Ratios obtained by a number of studies.

The lesson here is to be very careful of claims made on the basis of single cherry-picked studies. Especially when those making the claim have a bias they wish to confirm. Every claim should be critically and rationally considered using all the available studies.

Similar articles

 

March ’21 – NZ blogs sitemeter ranking

Image credit: What is the best way to get free traffic to my blog?

I notice a few regulars no longer allow public access to the site counters. This may happen accidentally when the blog format is altered. If your blog is unexpectedly missing or the numbers seem very low please check this out. After correcting send me the URL for your site meter and I can correct the information in the database.

Similarly, if your blog data in this list seems out of whack, please check your site meter. Usually, the problem is that for some reason your site meter is no longer working.

Sitemeter is no longer working so the total number of NZ blogs in this list has been drastically reduced. I recommend anyone with Sitemeter consider transferring to one of the other meters. See  NZ Blog Rankings FAQ.

This list is compiled automatically from the data in the various site meters used. If you feel the data in this list is wrong could you check to make sure the problem is not with your own site meter? I am of course happy to correct any mistakes that occur in the automatic transfer of data to this list but cannot be responsible for the site meters themselves. They do play up.

Every month I get queries from people wanting their own blog included. I encourage and am happy to respond to queries but have prepared a list of frequently asked questions (FAQs) people can check out. Have a look at NZ Blog Rankings FAQ. This is particularly helpful to those wondering how to set up sitemeters. Please note, the system is automatic and relies on blogs having sitemeters which allow public access to the stats.

Here are the rankings of New Zealand blogs with publicly available statistics for March 2021. Ranking is by visit numbers. I have listed the blogs in the table below, together with monthly visits and page view numbers. Meanwhile, I am still keen to hear of any other blogs with publicly available sitemeter or visitor stats that I have missed. Contact me if you know of any or wish help adding publicly available stats to your bog.

You can see data for previous months at Blog Ranks

Subscribe to NZ Blog Rankings Subscribe to NZ blog rankings by Email Find out how to get Subscription & email updates

Rank Blog Visits/month Page Views/month
1The Daily Blog61900283680
2Liturgy3388942005
313th Floor2393226897
4Sacraparental1700519667
5Tikorangi: The Jury Garden1543417167
6Cycling in Christchurch1446715511
7Creative Maths923710967
8Bill Bennett85399047
9Homepaddock82689153
10Free range statistics762610802
11SciBlogs554314889
12Music of sound49946768
13Lost in silver fern40516259
14Offsetting behaviour40034481
15Woodleigh Nursery30285245
16Nom Nom Panda28663064
17Jontynz25093161
18The Meaning of Trees17242751
19Anglican down under16852028
20Talking Auckland14381605
21Open Parachute14161797
22The Global Couple13881614
23Fields of Blood13541582
24The Woolshed Wargamer13332368
25Sarah the Gardener13241745
26No Minister12301421
27Reading the maps11161539
28A communist at large9201052
29Muffin-Mum883915
30Hot Topic8421087
31Off the couch721880
32Rodney’s Aviation Ramblings680844
33TVHE619736
34Pdubyah – a life just as ordinary591635
35Look, Think, Make579648
36Vomkrieg566674
37Economics New Zealand471571
38Kiwi Cakes426466
39Home education Foundation390482
40Stratford Aerodrome382417
41Aughts and Oughtisms374513
42AmeriNZ371536
43Quote Unquote345367
44Fun with Allergy Kids324423
45Media Sport and Other Rantings294300
46Perissodactyla273304
47Climate Justice Taranaki263374
48New Zealand Conservative257269
49Communication, Church, Society251342
50Tales from a Caffeinated Weka249262
51Cambridge NZ235276
52Eye on the ICR179209
53Sparrowhawk/Karearea178215
54Save our Schools NZ164181
55Mrs Cake160221
56Creative Voice#138212
57AnneKcam132169
58Right Reason129129
59The Catalyst122169
60Social Media & the 2014 Election111125
61goNZo Freakpower Brains Trust103104
62Room 5 @ Melville Intermediate School101113
63Keeping Stock9396
64Undeniably Atheist8893
64Mountains of Our Minds#88113
66Ideologically impure8388
67Room One @ Auroa School80104
68John Macilree’s Weblog#7786
69Unity Blog7476
69My thinks7481
71Aotearoa: A wider perspective6977
72Tauranga Blog6570
73Glennis’s Blog Page#58117
74Exile in New zealand5457
75Wokarella5360
76James McKerrow – Surveyor 1834-1919#4549
77Put ’em all on an island4456
78Anne Free Spirit4357
79Wellington Chic3939
80Software development and stuff3839
81Quietly in the backgroud3742
82Glenview 93246
83Dad4justice2830
83Family integrity2828
85Taradale Blog#2526
86Socialist Aotearoa2424
87ElephaNZa2223
88MartinIsti Blog2126
88The Official Ebenezer Teichelmann Blog#2121
90Get Out Gertrude!1919
91University of Otago, Law Library Blog1717
92ah! New Year’s Resolution1515
92Cut your hair1515
94bread and pomegranates1417
94Nelsonian’s life1415
96John Macilree’s Blog1212
96kiwi simplexity1212
96Sharlene says1212
99Journey to a mini me1111
99SmallTorque1112
99Four seasons in one1111
102Chris Jillet – Mountaineer#1010
103Carolyn’s blog911
103The Well read Kitty99
103MandM99
103Room 24, 2012910
107Helen Heath77
108Samuel Dennis66
108Warrington Taylor#66
110New Zealand female Firefighter calendar55
111High voltage learning during the Christchurch earthquakes44
111kiwiincanberra44
111The Little Waaagh! That Could44
114Blogger at Large33
114Utopia – you are standing in it33
116New Zealand Indian Fine Arts Society22
117Misses Mac11

sasas

An open letter to Paul Connet and the anti-fluoride movement

Paul Connett and Vyvyan Howard have, through the local Fluoride Free New Zealand activist group, published an open letter addressed to NZ scientists and educators (see An Open Letter To NZ Scientists And Educators). It is strange to encourage scientific exchanges through press releases but if they are seriously interested in an exchange of informed scientific opinion on the research they mention I am all for it.

In fact, I renew my offer to Paul Connett for a new exchange on the new relevant research along the lines of the highly successful scientific exchange we had in 2013/2014 summarised in Conett & Perrott (2014) The Fluoride Debate.

Connett and Howard say they felt “let down” by the reception they received in their 2018 visit. But they should realise this sort of ridicule is inevitable when a supposedly scientific message is promoted by activist fringe groups with known funding by big business (in this case the “natural”/alternative health industry). The science should be treated more respectably and discussed in a proper scientific forum or via a proper scientific exchange rather than political style activist meetings.

It is this sort of respectable, informed and open scientific exchange I am offering to Paul Connett and Vyvyan Hoard.

Connett and Howard argue that there has recently been  “a dramatic change in the quality of these [fluoride] studies.” I agree that new research occurs all the time and there is plenty of scope upgrading of the scientific exchange we had in 2013/2014 to cover that new research. Consideration of the new research requires the objective, critical and intelligent consideration scientists are well used to and this is not helped by activist propaganda meetings. So I encourage Connett and Howard to accept my offer. after all, if they are confident in their own analysis of this research what do they have to lose?

Inaccuracies in “open letter”

One can see an “Open letter” as displaying a willingness to enter into a proper scientific exchange. However, Connett and Vivyan’s open letter includes inaccuracies and misinformation on the new research which simply demonstrates that a one-sided presentation cannot present the research findings properly.

For example, they misrepresent the 2014 New Zealand fluoridation review of Eason et al (2014). Health effects of water fluoridation: A review of the scientific evidence. Even to the extent of mistaking the authors (not Gluckman & Skegg as they claim) and misrepresenting the small mistake made in the summary which was later corrected. That attitude does not bode well for the proper consideration of the research.

Connett and Howard concentrate on new research relating child IQ to fluoride intake but they ignore completely the fact that all the research comparing IQ in fluoridated and unfluoridated areas show absolutely no effect. I have summarised the results for the three papers involve in this table.

Instead, they concentrated on a few extremely weak relationships reported in a few papers. But even here they get this wrong – for example, they say there is “a loss of about 4 IQ points in offspring for a range of 1 mg/liter of fluoride in mother’s urine.” The paper they refer to (Green et al 2019) actually found no statistically significant relationship between child IQ and maternal urinary fluoride for all children considered. The relationship Connett and Howard mention was actually for male children (no relationship for female children or for all children) and was very weak. These sort of weak relationships are commonly found in epidemiological research and are usually meaningless. In this case, Connett and Howard have simply cherry-picked one value and misrepresented it as applying to all children.

Both the Green et al (2019) and Till et al (2020) papers Connett and Howard refer to suffer from selecting a few weak statistically significant relationships and ignoring the larger number of non-significant relationships they found for the data they investigated. Connett and Howard also completely ignored the new studies that don’t fit their claims. For example that of Santa-Marina et al (2019). Fluorinated water consumption in pregnancy and neuropsychological development of children at 14 months and 4 years of age. which showed an opposite positive relationship of child IQ with maternal urinary fluoride. Similar they ignored the large Swedish study of Aggeborn & Öhman (2020). The Effects of Fluoride in the Drinking Water showing no effect of fluoride on IQ but positive effects on oral health and employment possibilities in later life.

In conclusion, I reiterate that genuine open scientific exchanges do not take place via press release and activist meetings. However, the fact that Connett and Howard have issued an “Open Letter” could be interpreted as inviting others to participate in a proper exchange. I endorse that concept and offer Connett and Howard space for a free and open exchange on the new research at this blog site.

Similar articles

 

February ’21 – NZ blogs sitemeter ranking

Image credit: POLITICAL BLOG

I notice a few regulars no longer allow public access to the site counters. This may happen accidentally when the blog format is altered. If your blog is unexpectedly missing or the numbers seem very low please check this out. After correcting send me the URL for your site meter and I can correct the information in the database.

Similarly, if your blog data in this list seems out of whack, please check your site meter. Usually, the problem is that for some reason your site meter is no longer working.

Sitemeter is no longer working so the total number of NZ blogs in this list has been drastically reduced. I recommend anyone with Sitemeter consider transferring to one of the other meters. See  NZ Blog Rankings FAQ.

This list is compiled automatically from the data in the various site meters used. If you feel the data in this list is wrong could you check to make sure the problem is not with your own site meter? I am of course happy to correct any mistakes that occur in the automatic transfer of data to this list but cannot be responsible for the site meters themselves. They do play up.

Every month I get queries from people wanting their own blog included. I encourage and am happy to respond to queries but have prepared a list of frequently asked questions (FAQs) people can check out. Have a look at NZ Blog Rankings FAQ. This is particularly helpful to those wondering how to set up sitemeters. Please note, the system is automatic and relies on blogs having sitemeters that allow public access to the stats.

Here are the rankings of New Zealand blogs with publicly available statistics for February 2021. The ranking is by visit numbers. I have listed the blogs in the table below, together with monthly visits and page view numbers. Meanwhile, I am still keen to hear of any other blogs with publicly available sitemeter or visitor stats that I have missed. Contact me if you know of any or wish help adding publicly available stats to your bog.

You can see data for previous months at Blog Ranks

Subscribe to NZ Blog Rankings Subscribe to NZ blog rankings by Email Find out how to get Subscription & email updates

Continue reading

Data dredging, p-hacking and motivated discussion in anti-fluoride paper

Image credit: Quick Data Lessons: Data Dredging

Oh dear – another scientific paper claiming evidence of toxic effects from fluoridation. But a critical look at the paper shows evidence of p-hacking, data dredging and motivated reasoning to derive their conclusions. And it was published in a journal shown to be friendly to such poor science.

The paper is:

Cunningham, J. E. A., Mccague, H., Malin, A. J., Flora, D., & Till, C. (2021). Fluoride exposure and duration and quality of sleep in a Canadian population-based sample. Environmental Health, 1–10.

Data dredging

This study used data from a Canadian database – the Canadian Health Measures Survey. Databases with large numbers of variables tempt researchers to dredge for data or relationships which confirm their biases. Despite the loss of statistical significance in this approach data dredging or data mining is quite common in epidemiological studies.

Cunningham et al (2021) looked for relationships using two separate measure of fluoride exposure and four different measures of possible sleep disturbance. They found a “statistically significant (p<0.05) relationship between lower sleep duration and water fluoride. But no relationships for higher sleep duration, trouble sleeping or daytime sleepiness with either water fluoride or urinary fluoride. Their results for logical regression analysis are summarised in this figure. (Error bars crossing an Odds Ratio value of 1.0 indicate that the relationship is not statistically significant and p<0.05).

Of the 8 relationships investigated only 1 was statistically significant.

p-hacking

I discussed the problem of p-hacking in Statistical manipulation to get publishable results.

With a large dataset, one can inevitably find relationships that satisfy the p<0.05 criteria – because this p-value value is meaningless when multiple relationships are considered. One can even find such “statistically significant relationships” when random datasets are investigated (see Science is often wrong – be criticalI don’t “believe” in science – and neither should you, The promotion of weak statistical relationships in science  and Can we trust science). Once multiple relationships are investigated the chance of finding accidental relationships is much greater than 1 in 20 signified by the p<0.05 value.

So, one of the 8 relationships above satisfied the p<0.05 criteria when considered alone. But as part of multiple investigations, the chance of finding such a relationship by chance is much greater than 1 in 20.

Motivated reasoning

This paper smacks of motivated reasoning. The authors obviously have a commitment to the concept that fluoride causes problems with the pineal gland and drag up anything they can find in the literature to support this – without critically assessing the quality of the cited work or even mentioning the fact that the cited studies were made at much higher fluoride concentration on non-human animals. In effect, they are attempting to convert very weak results, obtained by data dredging and p-hacking, to a fact. They are attempting to make a purse out of a sow’s ear.

This research group is not new to this game. I commented on this in my critique of another sleep disorder paper from the group (see ).

Many of the same researchers are listed as authors on both papers – yet Cummingham et al (2021 ) cite the previous paper as if it was an independent study. They say “As far as we are aware, this is only the second human
study investigating the effects of fluoride exposure on sleep outcomes” which is simply disingenuous considering the involvement of the same researchers in both papers.

Both these papers were also published in the same journal – Environmental Health – a pay-to publish-journal that is known to be friendly to anti-fluoride researchers and uses very sympathetic peer reviewers (see ). The Chief editor, Philippe Grandjean, is well known for his opposition to fluoridation. I commented on his refusal to consider a paper of mine that critiqued an anti-fluoride paper published in his journal (see Fluoridation not associated with ADHD – a myth put to rest).

Conclusion

Yet another very weak study, published in an anti-fluoride friendly pay-to-publish journal with poor peer review. Despite the weaknesses due to data dredging, p-hacking and motivated reasoning, anti-fluoride activists will cite the single “statistically significant” result as gospel and ignore the 7 relationships that are not significant. As for inadequate consideration of confounders or other risk-modifying factors, this study ignores completely the fact that city size and geographic factors have a strong effect on both sleep patterns and water fluoride concentrations (see Perrott 2018). Such inadequate consideration of confounders is another common problem in epidemiological studies.

Oh, well, we are not a rational species. More a rationalising one. And in such areas motivated rationalisation and confirmation bias is rife.

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Censorship: Thinking you are right – even if you’re wrong

I posted this video four years ago – but repost it now because the message is still very valid (see Are you really right? and Warriors, scouts, Trump’s election and your news media). In fact, it’s more valid today than it was four years ago. Things have got worse – far worse than I expected they would.

To recap – Julia describes the two different mindsets required in fighting a war:

  • The  “Warrior mindset” – emotively based and fixated on success. Not interested in stopping to think about the real facts or rationally analyse the situation.
  • The “Scout mindset” – objective and rational, ready to consider the facts (in fact, searching them out) and logically consider possibilities.

Unfortunately the “warrior mindset” – emotively based and not considering the facts or rationally analysing the situation – may be required in war but now seems to be the standard approach in politics (maybe even in science for some people). The “scout mindset” is unfortunately rare – and actually disapproved of when it occurs. Things have got worse in that respect.

There is another unfortunate dimension to this. Just as people have become convinced that they themselves are the fountains of truth, and their opponents fountains of untruth, there is now the drive to censor. Many people are arguing that people they disagree with should be denied access to the media, especially social media. And they jump on the media when their opponents are given space.

Hell, the media itself is encouraging this. Nowadays we have silicon valley corporations, which control social media, determining who should have a voice. And some people who should know better are applauding them for this. Applauding selfishly because they want to see their discussion opponents denied a voice. This is not just cowardly but extremely short-sighted of them – what will they do when they, in turn, are denied a voice by these very same corporations?

Whatever happened to the old adage – “I Disapprove of What You Say, But I Will Defend to the Death Your Right to Say It?” I grew up thinking this was a widely approved ideal but now find the people who I had considered “right-minded,” “free thinkers,” and “liberals” have almost completely abandoned it. They seem to be the first in line to impose censorship and the last to complain when censorship happens.

The folly of censorship

Censorship, the attempt to close down a rational discussion, hardly gives the impression that the supporters of censorship have truth on their side. If anything it suggests they do not have the arguments and this, in effect, hands victory to the ones censored.

It is short-sighted and cowardly and does not close down the discussion – it simply moves it elsewhere. And usually to a forum in which the instigators or supporters of the censorship have little input. 

Censorship usually hands the moral high ground to the ones being censored – and cheaply as they have gained this without even having their ideas (rational or irrational) tested in meaningful discussion.

There is a lot of truth in the old saying that sunlight is the best disinfectant – and refusal to allow this only encourages bad ideas to proliferate unchecked.

That is not to say all the ideas being censored are “bad” – many plainly aren’t. But will those who censor or support censorship (or indulge in self-censorship –  another common problem with people I used to respect) ever know? In the end, the censors and their supporters simply end up living in their own silo or bubble, seemingly oblivious to many of the ideas circulating in society or the world. Ideas they could perhaps have learned something from. Even if the ideas one wishes to censor are based on misinformation or misunderstanding the exercise of debating them can teach things to both sides. Censorship, and especially self-censorship, prevents self-development.

Arbitrary or ideologically motivated censorship?

Often censorship by social media appears arbitrary, perhaps driven by algorithms. For example, Twitter recently blocked the official account of Russian Arms Control delegation in Vienna, engaged in negotiations on the Open Skies Treaty and other important issues. It was later reinstated – without explanation or apology – but followers were lost. Arbitrary or not, should such an important body, involved in negotiations critical for the whole planet, be censored?

Are those algorithm innocent or objective? These days we see social media like Twitter and Facebook employing staff with political backgrounds. Even people who have previously worked in, or still work in, bodies like the Atlantic Council which is connected with NATO. And the revolving door by which ex-politicians and intelligence staff get employed in the mainstream media is an open secret. These people openly describe information coming from “the other side” as “disinformation,” “fake news,” or “state-supported propaganda” so have no scruples about censoring it or otherwise working to discredit it (for example labelling news media as state-controlled – but only for the “other side” – eg RT, but not the BBC or Voice of America).

Ben Nimmo, a member of the Atlantic Council, and well-known for his aggressive political views, recently announced his move to Facebook

This biased approach to information or social discussion is strongly driven by an “official” narrative. A narrative promoted by military blocks, their governments and their political leaders. But even unaffiliated persons approaching social discussion can be, and usually are, driven by a narrative. A narrative that they often strongly and emotionally adhere to. Juna Galef’s “warrior mindset.” That is only human. It’s a pity, but probably few participants in social discussions get beyond this mindset and adopt the far more useful (for obtaining objective truth) “scout mindset” which is objective and rational, ready to consider the facts (in fact, searching them out) and logically considers possibilities.

But let’s face it. If you support censorship, or even instigate censorship in social media you control, how likely is it that you can get beyond the “warrior mindset?” The “scout mindset” by necessity requires open consideration of views and facts you may initially disagree with. Censorship, especially self-censorship, prevents that. It prevents personal growth.

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Embarrassing knock-back of second draft review of possible cognitive health effects of fluoride

We have come to expect exaggeration of scientific findings in media reports and institutional press releases. But it can also be a problem is original scientific publications where findings are reported in an unqualified or exaggerated way. Image Credit: Curbing exaggerated reporting

This is rather embarrassing for a US group attempting to get the science right about possible toxic effects of fluoride. It’s also embarrassing for the anti-fluoride activists who have “jumped the gun” and been citing the group’s draft review as if it was reliable when it is not.

The US National Academies of Sciences, Engineering, and Medicine (NAS) have released their peer-review of the revised US National Toxicity Program (NTP) draft on possible neurodevelopmental effects of fluoride (see Review of the Revised NTP Monograph on the Systematic Review of Fluoride Exposure and Neurodevelopmental and Cognitive Health Effects).

This is the second attempt by the NTP reviewers to get acceptance of their draft and it has now been knocked back by the NAS peer reviewers for a second time.

Diplomatic but damning peer-review

Of course, the NAS peer reviewers use diplomatic language but the peer review is quite damning. It criticises the NTP for ignoring some of the important recommendations in the first peer review. One which is quite critical was the lack of response to the request that NTP explains how the monograph can be used (or not) to inform water fluoridation concentrations. The second NAS peer review firmly states that the NTP:

“should make it clear that the monograph cannot be used to draw any conclusions regarding low fluoride exposure concentrations, including those typically associated with drinking-water fluoridation.”

And:

“Given the substantial concern regarding health implications of various fluoride exposures, comments or inferences that are not based on rigorous analyses It seems to me that there is soime internal politicsshould be avoided.”

It seems to me there is some internal politics involved and some of the NTP authors may be promoting their own, possibly anti-fluoride, agenda. Certainly, the revised NTP draft monograph continues to obfuscate this issue. It continues to state that “fluoride is presumed to be a cognitive neurodevelopmental hazard to humans” – a clause which anti-fluoride campaigner consistently quote out of context. Yes, it does state that this is based on findings demonstrating “that higher fluoride exposure (e.g., >1.5 mg/L in drinking water) is associated with lower IQ and other cognitive effects in children.” But this is separated from the other fact that the findings on cognitive neurodevelopment for “exposures in ranges typically found in drinking water in the United States (0.7 mg/L for optimally fluoridated community water systems)” are “are inconsistent, and therefore unclear.”

Monograph exaggerates by enabling unfair cherry-picking

So, you see the problem. The draft NTP monograph correctly refers to IQ and other cognitive effects in children exposed to excessive levels of fluoride. The draft also correctly refers to that lack of evidence for such effects at lower fluoride exposure levels typical of community water fluoridation. But in different places in the document.

The enables activist cherry-picking to support an anti-fluoride agenda and that is a fault of the document itself. It should clearly state that the monograph should not be used to draw any conclusion at these low exposure levels. This is strongly expressed in the peer-reviewers’ comments.

I find the blanket “presumed to be a hazard for humans” quite misleading. For example, no one says that calcium is “presumed to be a cardiovascular hazard to humans.” Or that selenium is “presumed to be a cardiovascular or neurological hazard to humans.” Or what about magnesium – would you accept that it is a “presumed neurological hazard to humans?” Would you accept that iron is a “presumed cardiovascular, cancer, kidney or erectile dysfunction hazard to humans?” Yet all those problems have been reported for humans at high intake levels of these elements.

No, we sensibly accept that various elements and microelements have beneficial, or essential benefits, to humans at reasonable intake levels., Then we sensibly warn that these same elements can be harmful at excessive intake. To proclaim that any of these elements are “presumed” to be hazardous – without clearly saying at excessive intake levels, is simply distorting or exaggerating the data.

What does “presumed” mean?

A lot of readers find the use of “presumed” strange. But it’s meaning is related to the levels of evidence found by reviewers.

No, don’t believe those anti-fluoride activists who falsely claim that “presumed” is the highest level of evidence and that the finding should be treated as factual. They are simply wrong.

Some idea of the word’s use is presented in this diagram from the NTP revised draft monograph.

So “presumed” means that the evidence for the effect is moderate. That the effect is not factual or known. But as further evidence comes in the ranking of fluoride as a hazard may increase, or decline.

As the monograph bases this “presumed” rating solely on evidence from areas of endemic fluorosis where fluoride intake levels are high it is correct to avoid stating the effects as factual. For example, consider these images from areas of endemic fluorosis in China (taken from a slide presentation by Xiang 2014):

Clearly, people in these areas suffer a range of health effects related to the high fluoride intake. The cognitive effects like IQ loss from these areas could result from these other health effects, not directly from fluoride (although excessive fluoride intake leads to the health effects).

So we can “presume” that fluoride (in areas of endemic fluorosis where fluoride intake is excessive) is a “cognitive neurodevelopmental hazard for humans” but we can not factually state that the neurodevelopment effects are directly caused by fluoride. That would require further scientific work to elucidate the specific mechanisms involved in creating that effect.

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The promotion of weak statistical relationships in science

Image credit: Correlation, Causation, and Their Impact on AB Testing

Correlation is never evidence for causation – but, unfortunately, many scientific articles imply that it is. While paying lip service to the correlation-causation mantra, some (possibly many) authors end up arguing that their data is evidence for an effect based solely on the correlations they observe. This is one of the reasons for the replication crisis in science where contradictory results are being reported. Results which cannot be replicated by other workers (see I don’t “believe” in science – and neither should you).

Career prospects, institutional pressure and the need for public recognition will encourage scientists to publish poor quality work that they then use to claim that have found an effect. The problem is that the public, the news media and even many scientists simply do not properly scrutinise the published papers. In most cases they don’t have the specific skills required for this.

There is nothing wrong with doing statistical analyses and producing correlations. However such correlations should be used to suggest future more meaningful and better-designed research like randomised controlled trials (see Smith & Ebrahim 2002Data dredging, bias, or confounding. They can all get you into the BMJ and the Friday papers. ). They should never be used as “proof” for an effect, let alone argue that the correlation is evidence to support regulations and advise policymakers.

Hunting for correlations

However, researchers will continue to publish correlations and make great claims for them because they face powerful incentives to promote even unreliable research results. Scientific culture and institutional pressures provide expectations demanding academic researchers produce publishable results. This pressure is so great they will often clutch at straws to produce correlations even when the initial statistical analyst produces none. They will end up “torturing the data.”

These days epidemiological researchers use large databases and powerful statistical software in their search for correlations. Unfortunately, this leads to data mining which, by suitable selection of variables, makes the discovery of statistically significant correlations easy. The data mining approach also means that the often cite p-values are meaningless. P-values measure the probability the relationship occurs by chance and often cited as evidence of the “robustness” of the correlations. But probability is so much greater when researchers resort to checking a range of variables and that isn’t reflected properly in the p-values.

Where data mining occurs, even to a limited extent, researchers are simply attempting to make a purse out of sow’s ear when they support their correlations merely by citing a p-value < 0.05  because these values are meaningless in such cases. The fact that so many of these authors often ignore more meaningful results from their statistical analyses (like R-squared values which indicate the extent that the correlation “explain” the variation in their data) underlines their deceptive approach.

Poor statistical relationships

Consider these correlations below – two data sets are taken from a published paper – the other four use random data provided by Jim Jones in his book Regression Analysis: An Intuitive Guide.

You can probably guess which correlations were from real data (J and M) because there are so many more data points All of these have correlations low p values – but of course, those selected from random data sets resulted from data mining and the p-values are therefore meaningless because they are just a few of the many checked. Remember, a p-value < 0.05 means that the probability of a chance effect is one in twenty and more than twenty variable pairs were checked in this random dataset.

The other two correlations are taken from Bashash et al (2017). They do not give details of how many other variables were checked in the dataset used but it is inevitable that some degree of data mining occurred. So, again, the low p-values are probably meaningless.

J provides the correlation of General Cognitive Index (GCI) scores in children at age 4 years with maternal prenatal urinary fluoride and M provides the correlation of children’s IQ at age 6–12 y with maternal prenatal urinary fluoride. The paper has been heavily promoted by anti-fluoride scientists and activists. None of the promoters have made a critical, objective, analysis of the correlations reported. Paul Connett, director of the Fluoride Action Network, was merely supporting his anti-fluoride activist bias when he uncritically described the correlations as “robust.” They just aren’t.

There is a very high degree of scattering in both these correlations, and the R-squared values indicate they cannot explain any more than about 3 or 4% of the variance in the data. Hardly something to hang one’s hat on, or to be used to argue that policymakers should introduce new regulations controlling community water fluoridation or ban it altogether.

In an effort to make their correlations look better these authors imposed confidence intervals on the graphs (see below). This Xkcd cartoon on curve fitting gives a cynical take on that. The grey areas in the graphs may impress some people but it does not hide the wide scatter of the data points. The confidence intervals refer to estimates of the regression coefficient but when it comes to using the correlations to predict likely effects one must use the prediction intervals which are very large (see Paul Connett’s misrepresentation of maternal F exposure study debunked). In fact, the estimated slopes in these graphs are meaningless when it comes to predictions.

Correlations reported by Bashash et al (2017). The regressions explain very little of the variance in the data and connect be used to make meaningful predictions.

In critiquing the Bashash et al (2017) paper I must concede that at least they made their data available – the data points in the two figures. While they did not provide full or proper results from their statistical analysis (for example they didn’t cite the R-squared values) the data does at least make it possible for other researchers to check their conclusions.

Unfortunately, many authors simply cite p-values and possible confidence intervals for the estimate of the regression coefficient without providing any data or images. This is frustrating for the intelligent scientific reader attempting to critically evaluate their claims.

Conclusions

We should never forget that correlations, no matter how impressive, do not mean causation. It is very poor science to suggest they do.

Nevertheless, many research resort to correlations they have managed to glean from databases, usually resorting to some extent of data mining, to claim they have found an effect and to get published. The drive to publish means that even very poor correlations get promoted and are used by ideologically or career-minded scientists, and by activists, to attempt to convince policymakers of their cause.

Image credit: Xkcd – Correlation

Remember, correlations are never evidence of causation.

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Can we trust science?

Image credit: Museum collections as research data

Studies based simply on statistically significant relationships found by mining data from large databases are a big problem in the scientific literature. Problematic because data mining, or worse data dredging, easily produces relationships that are statistically significant but meaningless. And problematic because authors wishing to confirm their biases and promote their hypotheses conveniently forget the warning that correlation is not evidence for causation and go on to promote their relationships as proof of effects. Often they seem to be successful in convincing regulators and policymakers that their serious relationships should result in regulations. Then there are the activists who don’t need convincing but will promote willingly and tiresomely these studies if they confirm their agendas.

Even random data can provide statistically significant relationships

The graphs below show the fallacy of relying only on statistically significant relationships as proof of an effect. The show linear regression result for a number of data sets. One data set is taken from a published paper – the rest use random data provided by Jim Jones in his book Regression Analysis: An Intuitive Guide.

All these regressions look “respectable.” They have low p values (less than the conventional 0.05 limit) and the R-squared values indicated they “explain” a large fraction of the data – up to 49%. But the regressions are completely meaningless for at least 7 of the 8 data sets because the data were randomly generated and have no relevance to real physical measurements.

This should be a warning that correlations reported in scientific papers may be quite meaningless.

Can you guess which of the graphs is based on real data? It is actually the graph E – published by members of a North American group currently publishing data which they claim shows community water fluoridation reduces child IQ. This was from one of their first papers where they claimed childhood ADHD was linked to fluoridation (see Malin, A. J., & Till, C. 2015. Exposure to fluoridated water and attention deficit hyperactivity disorder prevalence among children and adolescents in the United States: an ecological association).

The group used this paper to obtain funding for subsequent research. They obviously promoted this paper as showing real effects – and so have the anti-fluoride activists around the world, including the Fluoride Action Network (FAN) and its director Paul Connett.

But the claims made for this paper, and its promotion, are scientifically flawed:

  1. Correlation does not mean causation. Such relationships in larger datasets often occur by chance – hell they even occur with random data as the figure above shows.
  2. Yes, the authors argue there is a biologically plausible mechanism to “explain” their association. But that is merely cherry-picking to confirm a bias and there are other biologically plausible mechanisms they did not consider which would say there should not be an effect. The unfortunate problem with these sorts of arguments is that they are used to justify their findings as “proof” of an effect. To violate the warning that correlation is not causation.
  3. There is the problem of correcting for cofounders or other risk-modifying factors. While acknowledging the need for future studies considering other confounders, the authors considered their choice of socio-economic factors was sufficient and their peer reviewers limited their suggestion of other confounders to lead. However, when geographic factors were included in a later analysis of the data the reported relationship disappeared. 

Confounders often not properly considered

Smith & Ebrahim (2002) discuss this problem an article  – Data dredging, bias, or confounding. They can all get you into the BMJ and the Friday papers. The title itself indicates how the poor use of statistics and unwarranted promotion of statical analyses can be used to advance scientific careers and promote bad science in the public media.

These authors say:

“it is seldom recognised how poorly the standard statistical techniques “control” for confounding, given the limited range of confounders measured in many studies and the inevitable substantial degree of measurement error in assessing the potential confounders.”

This could be a problem even for studies where a range of confounders are included in the analyses. But Malin & Till (2015) considered the barest minimum of confounders and didn’t include ones which would be considered important to ADHD prevalence. In particular, they ignored geographic factors and these were shown to be important in another study using the same dataset. Huber et al (2015) reported a statistically significant relationship of ADHD prevalence with elevation. These relationships are shown in this figure

Of course, this is merely another statistically significant relationship – not proof of a real effect and no more justified than the one reported by Malin and Till (2015). But it does show an important confounder that Malin & Till should have included in their statistical analysis.

I did my own statistical analysis using the data set of Malin & Till (2015) and Huber et al (2015) and showed (Perrott 2018) that inclusion of geographic factors showed there was no statistically significant relationship of ADHD prevalence with fluoridation as suggest by Malin & Till (2015). Their study was flawed and it should never have been used to justify funding for future research on the effect of fluoridation. Nor should it have been used by activists promoting an anti-fluoridation agenda.

But, then again, derivation of a statistically significant relationship by Malin & Till (2o15) did get them published in the journal Environmental Health which, incidentally, has sympathetic reviewers (see Some fluoride-IQ researchers seem to be taking in each other’s laundry) and an anti-fluoridation Chief Editor – Phillipe Grandjean (see Special pleading by Philippe Grandjean on fluoride). It also enabled the promotion of their research via institutional press releases, newspaper article and the continual activity of anti-fluoridation activists. Perhaps some would argue this was a good career move!

Conclusion

OK, the faults of the Malin & Till (2015) study have been revealed – even though Perrott (2018) is studiously ignored by the anti-fluoride North American group which has continued to publish similar statistically significant relationships of measures of fluoride uptake and measures of ADH or IQ.

But there are many published papers – peer-reviewed papers – which suffer from the same faults and get similar levels of promotion. They are rarely subject to proper post-publication peer-review or scientific critique. But their authors get career advancement and scientific recognition out of their publication. And the relationships are promoted as evidence for real effects in the public media.

No wonder members of the public are so often confused by the contradictory reporting, the health scares of the week, they are exposed to.

No wonder many people feel they can’t trust science.

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