Time to give up on Sitemeter

bz-panel-05-26-11MODERN

Bizarro Cartoon 5-26-2011  from Some visitors unknowingly redirected to ads! (Finding vindicosuite.com on outclicks).

This cartoon from Lola Jane’s World will resonate with many bloggers – especially those who using Sitemeter to collect their visitor stats.

New Zealand bloggers who take part in the monthly NZ Blog ranking will know what I mean. In recent months, many bloggers using Sitemeter have not had any visitor stats available and it has been impossible to include them in the blog ranking list.

I think the time has come for these bloggers to give up on Sitemeter, delete the code and install a stats counter that does work. In the Blog ranking FAQs I list alternative counters that are easy to install and manage:

StatCounter is the most popular and works very well at the moment. In the FAQs I give a little advice on how to install it.

Are bloggers leaving Sitemeter

Definitely – it’s not just local bloggers disappointed with the problems. Internationally bloggers have opted out – see for example Goodbye SitemeterGoodbye SitemeterWell, so Much for SitemeterSo is SiteMeter dead? and The End of the SiteMeter Era. And there are many more posts like this around.

Redirections problems

I hadn’t picked this up myself, but the problems seem to be more basic than the erratic return of the blog stats. A very common complaint is that the installed Sitemeter code causes visitors to a blog to be redirected elsewhere. See, for example, Apologies to All – Sitemeter Forced Redirect Problem Now Fixed (“fixed” by removing Sitemeter), Site Meter Rewriting Links on WordPress Sites and Blogger.com bloggers: check your template for Sitemeter redirect problem.

According to What do I Know? (see Sitemeter Out Of Control – UPDATED Again: July 9):

“Then at some point Sitemeter apparently was bought by MySpace.  Since then things have gone downhill.  Reports about MySpace selling information about  Sitemeter users would come up.  Sitemeter stopped answering any of my help requests or comments.”

That seems a very convincing reason for bloggers to remove the Sitemeter code from their blog – and, hopefully, install one of the alternatives.

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Christmas reading

Christmas isn’t far away. Perhaps some of you are already thinking of presents for the scientifically minded in your family. You could do a lot worse that gifting one of the books on the shortlist for the 2015 Royal Society Winton Prize for Science Books.

The list is now public – see Royal Society Winton Prize for Science Books. And if you must wait to see which one wins the prize then the judges will announce this at a public event on 24 September 2015, hosted by Professor Brian Cox OBE, Royal Society Professor for Public Engagement in Science.

The books on the shortlist are below, together with the judges comments and a link to discover more about the book. There is also a link to the first chapter of each book for those careful buyers who would like to read a bit before deciding on that gift.


Man Who Couldn’t Stop: OCD and the True Story of a Life Lost in Thought by David Adam

The judges said: “An amazingly gripping and informative look inside someone’s head, told with a depth of knowledge and genius turn of phrase that only an expert and gifted writer could wield.”

Download the first chapter of this book (PDF).


Alex Through the Looking-glass: How Life Reflects Numbers and Numbers Reflect Life  by Alex Belos

The judges said: “Bellos fizzes with enthusiasm, and his genuine love for the subject shines through and makes mathematics engaging and non-threatening even for math-phobes.”

Download the first chapter of this book (PDF).


Smashing Physics by Butterworth, Jon (2015) Paperback by Jon Butterworth

The judges said: “With his unique insider perspective, Butterworth has humanized a classic science story that we all thought we knew. His writing is so engaging that he makes some of the most advanced science around seem within our grasp.”

Download the first chapter of this book (PDF).


Life’s Greatest Secret: The Story of the Race to Crack the Genetic Code by Matthew Cob

The judges said: “A brilliantly written account of one of the most important scientific discoveries of the century, with a fresh perspective that also dispels the myths popularised by previous reports.”

Download the first chapter of this book (PDF).


Life on the Edge: The Coming of Age of Quantum Biology by Johnjoe Mcfadden and Professor Jim Al-Khalili

The judges said: “A topic that could have been incomprehensible to the average reader becomes unexpectedly enthralling in the hands of these skilled communicators. A controversial work that deserves its already wide audience.”

Download the first chapter of this book (PDF).


Adventures in the Anthropocene: A Journey to the Heart of the Planet We Made by Gaia Vince

The judges said: “Vince’s passion and strong voice grabs you instantly and the story she tells is truly original. A finely-crafted book on an important, urgent topic.”

Download the first chapter of this book (PDF).


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70th anniversary of first use of atomic weapon against civilians

Image credit: The Human Survival Project

Today is the 70th anniversary of the first ever use of an atomic weapon against humans – civilians at that.  The US dropped the bomb on the Japanese city of Hiroshima on August 6, 1945. Two days later they dropped another atomic bomb on Nagasaki.

There will be a lot of information circulating about this incident and its military and political significance. However, the Russian Historical Society has published an historical document which could be of interest. It is the just declassified report from Soviet ambassador to Japan on the aftermath of the bombings of Hiroshima and Nagasaki. It is from the Archive of Foreign Policy of Russia. The report was recorded a month after the attacks.

The original report is available on-line at Report of the Soviet ambassador to Japan about the state of the Hiroshima and Nagasaki atomic bomb. For those who do not read Russian here are the highlights (thanks to Fort Russ – Russia declassifies the report on the aftermath of the US nuclear bombings of Hiroshima and Nagasaki):


hirosima

The train terminal and the city of Hiroshima were destroyed so much that there was no shelter to hide from the rain.
The city was a scorched plain with 15-20 cement buildings left standing.
Several dozen thousand people huddled in the dugouts on the outskirts of the city.
People who came to help the victims during the first 5-10 days died.
A month after the bombing grass began to grow and new leaves appeared on the burned trees.
Glass windows in the cement building of police department, which was left standing, blew out inward. The ceiling was bulging upwards.
The zone of impact was 6-8 kilometers, where all the buildings were damaged.
At 5-6 kilometers mostly roofs were damaged.
Some areas were not affected by the rays, suggesting that the energy was expelled unequally by bursts. Some people who were close to the injured did not receive any burns. This pertains to sections significantly removed from the impact.
Everything alive was destroyed in the radius of one kilometer.
The sound and the flash were heard and seen 50 kilometers away.
On person reported seeing a flash and feeling a touch of a warm stream on his cheek and a needle pinch.
Many people only had injuries from shattered glass.
Burns were mainly on the face, arms and legs.
A doctor reported seeing three bombs dropped on parachutes, two of which did not explode and were collected by the military. The doctor experienced diarrhea after drinking the water. Other rescuers got sick after 36 hours. The doctor said that in those affected the white blood cell count reduced from 8000 per cubic centimeter to 3,000, 1,000 and even 300, which causes bleeding from nose, throat, eyes, and from the uterus in females. The injured die after 3-4 days.
The injured, who are evacuated heal faster. Those who drank or rinsed with water in the impact area died thereafter.
After a month it was considered safe to stay in the impact zone, however it was still not conclusive.
According to the doctor, rubber clothing offered protection against uranium, as well as any material which is a conductor of electricity.
A girl who visited the area a few days after the blast got sick in 1-2 weeks and died 3 days after.
Nagasaki is divided into two sections by a mountain. The section sheltered from the blast by a mountain had much less destruction.
Japanese driver in Nagasaki said no rescue work was done on the day of the bombing, because the city was engulfed in fire.
Nagasaki bomb was dropped over a university hospital in Urakami district (near a Mitsubishi plant), all the patients and the staff of the hospital died.
The driver said, some children who were up on the trees [playing?] survived, but those on the ground died.Most people in Hiroshima said the bomb was dropped on a parachute and detonated 500-600 feet above the ground.
The head of the sanitary service of the 5th American fleet, commander Willkatts said that no parachutes were used in the dropping of the bombs. He also said no bomb could fall without detonating.
He said after the bombing the zone of impact is safe and the Japanese are exaggerating the effects of a nuclear bomb.


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Connett misrepresents the fluoride and IQ data yet again

The video clip below shows how local body politicians can be fooled by people misrepresenting the science. The culprit (unsurprisingly for the fluoride issue) is Paul Connett, Executive Director of the anti-fluoride propagandist group Fluoride Action Network (FAN). He relies on his PhD to provide authority – and the fact that few people in his audiences have the time or background to check out his claims.

At the moment, Connett is putting a lot of effort into promoting the myth that fluoridation causes a decrease in IQ. In this very short video clip (just over 1 minute) of a recent presentation to the Denver Water Board Connett massages data reported by Xiang et al., (2003a) to pull the wool of the Board’s eyes..

The innocent victims in his audience, including the Denver Water Board members, were no doubt impressed by this graph Connet used.

It looks pretty convincing, doesn’t it? There appears to be a statistically very significant decrease in IQ with an increase in drinking water fluoride above about 1 ppm F? (Community water fluoridation [CWF] usually uses a concentration of about 0.7 ppm). All the data points are lined up in a row.

That is until you look at the original data.

This figure is from Xiang et al., (2003a).  Not so convincing, eh? Clearly, with such a wide scatter of the data,  fluoride is only part of the story – if it has any effect at all. But this is the sort of graph one needs to consider when looking at correlations. Connett obtained his figure by breaking the data up into ranges. It looks prettier – but is misleading.

One should always look at the original data.*

Although the correlation is statistically significant, urinary fluoride explains only 3% of the variance in IQ! This tells us that fluoride has very little effect on IQ and it is very likely that it would have no explanatory role at all once other factors were considered in the statistical analysis!

I think it is inhumane to make the claims Connett does on such a flimsy correlation. His biased advocacy is, in effect, denying any efforts to find the real causes of the IQ variation.

What about confounding factors?

Connett’s claim that data was “controlled for” confounding factors is just not true. Xiang did not include any of these other factors in the statistical analysis of the data in Figure 2.

He only compared average values of these factors for the two villages in the study. There were no proper correlations across all the data. Xiang reported no differences between villages for urinary iodine, family income, and parent’s education level. However, there was an average age difference between the villages and he reported that IQ was influenced by age. The drinking water arsenic concentrations were higher in the low fluoride village than the high fluoride village (Xiang et al., 2013).

Incidentally, in a later paper (Xiang et al., 2003b) presents data for blood lead. This time he did check for a correlation across all samples and found there was no statistically significant correlation with IQ. But this was separate and not incorporated into a statistical analysis together with fluoride concentrations.

There was no real checking for the effect of confounding factors on the correlation of IQ with fluoride.

Connett asks a silly question

Connett goes on to make an emotional appeal for scientists to produce convincing data showing that fluoride does not decrease IQ:

This question is disingenuous as science can never prove something can never happen – it can only consider the evidence for it happening. Evidence of the sort presented by Xiang et al. (2003a). Scientific reviews look at the evidence, consider its reliability, compare it with evidence from other studies and draw conclusions.

Connett is disparaging about scientific reviews of the fluoride literature because he does not understand that such literature requires critical and intelligent analysis. Things like the high concentrations and doses used in animals studies he refers to. And looking below surface claims to see what the data really says – as I have done here. This is what reviewers of the scientific literature do all the time.

All Connett has relied on here is his own confirmation bias – and his emotions. Policy makers should beware of such advocacy.

See also:

Connett fiddles the data on fluoride
Connett & Hirzy do a shonky risk assessment for fluoride

*Note: Observant readers might note the second figure compares IQ with urine fluoride concentration. Unfortunately, he did not give a similar figure for fluoride concentration in drinking water. However, this is well correlated with urine fluoride. And, as urine concentration is a better indicator of fluoride intake that drinking water concentration, this figure does give a useful picture of the variance in the data Xiang used.

Incidentally, I have made several attempts without success, to get the original water fluoride concentrations from Xiang (who has so far not replied to several emails) and Connett (who told me that he does not want me contacting him again!).

References

Xiang, Q; Liang, Y; Chen, L; Wang, C; Chen, B; Chen, X; Zhouc, M. (2003a). Effect of fluoride in drinking water on children’s intelligence. Fluoride, 36(2), 84–94.

Xiang, Q.; Liang, Y.; Zhou, M. . and Z. H. (2003b). BLOOD LEAD OF CHILDREN IN WAMIAO–XINHUAI INTELLIGENCE STUDY. Fluoride, 36(3), 198–199.

Xiang, Q., Wang, Y., Yang, M., Zhang, M., & Xu, Y. (2013). Level of fluoride and arsenic in household shallow well water in wamiao and xinhuai villages in jiangsu province, china. Fluoride 46(December), 192–197.

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Fluoridation: Newsweek science journalism bottoms out

One of the worst pieces of distortion and misrepresentation of the Cochrane Fluoridation Review is that written by an anti-fluoridation journalist Douglas Main in Newsweek – Fluoridation May Not Prevent Cavities, Scientific Review Shows. It has, of course, been heavily promoted by anti-fluoride activists.

Dr Charles Payet*, a dentist from Charlotte, NC, USA, has debunked this Newsweek article report in his blog article More Bad Journalism on Fluoride which is also a guest blog at Making sense of FluorideOoops, [Newsweek] Did It Again.

Readers should go to these original posts to read the full article.  However, here are a few quotes from important sections:


Cochrane-fluoridation-quote

Yes, Water Fluoridation Has Been Proven Effective

Main starts off with an awful mischaracterization of the Review by stating that “…while using fluoridated toothpaste has been proven to be good for oral health, consuming fluoridated water may have no positive impact.” Let’s take that apart quickly.

First of all, there’s no disagreement that fluoridated toothpaste has been good for oral health. However, to state that consuming fluoridated water may have no impact is to completely ignore all historical evidence as to the dramatic decrease in dental decay once standardized CWF was implemented for the first time in Grand Rapids, Michigan 80 years ago. Not only that, the Cochrane Review directly contradicts Main’s assertion:

“Data suggest that the introduction of water fluoridation resulted in a 35% reduction in [DMF] baby teeth and a 26% reduction in [DMF] permanent teeth. It also increased the percentage of children with no decay by 15%.”

How About the Quality of the Papers Included?

Next up, Main claims that the Review “…winnowed down the collection to only the most comprehensive, well-designed, and reliable papers.” Is that accurate? Sigh……no. No it’s not. Let’s turn back to the Review to see what it says [emphasis mine]:

“For caries data, we included only prospective studies with a concurrent control, comparing at least two populations, one receiving fluoridated water and the other non-fluoridated water, with at least two points in time evaluated. Groups had to be comparable in terms of fluoridated water at baseline. For studies assessing the initiation of water fluoridation the groups had to be from nonfluoridated areas at baseline, with one group subsequently having fluoride added to the water. For studies assessing the cessation of water fluoridation, groups had to be from fluoridated areas at baseline, with one group subsequently having fluoride removed from the water.”

In other words, the Review only selected what are called “prospective” studies. While these are generally considered to be of higher quality better than cross-sectional studies, (performed at one point in time) for identifying causes, they are also much more difficult, and sometimes impossible, to do.  They are especially difficult today for one important reason when it comes to fluoride: because so many communities have already been fluoridated for a long time, it is very difficult to find one or more in which to set up a prospective study today, and the regulatory hurdles in doing so are enormous.

Therefore, it is false to claim that the Review only included the “most comprehensive, well-designed, and reliable papers.” In fact, the Review included one type of study regardless of their quality. Beyond that the Review’s discussion actually noted that more recent cross-sectional studies were often of better quality because computer use enabled better statistical analysis and consideration of confounding factors.


Payet also discusses the Cochrane judgement of study quality which Main and other anti-fluoride propagandists have misrepresented:


The Review judged quality using blinded randomised controlled studies (RCTs) commonly recommended for clinical drug trials as their baseline. However, they acknowledged this criteria is usually impossible to achieve in fluoridation studies because the assignment of subjects into a treated group versus a control group is outside the control of the investigator. Instead, researchers must use observational studies. Dr John Beal noted in his response to the Cochrane Health Group’s blog The value of cross-sectional studies on the dental benefits of water fluoridation – a response from Dr John Beal to the Cochrane Oral Health Group blog, the claim that cross-sectional, observational, studies, which were all excluded, are somehow of lower quality than RCTs, is false because a previous Cochrane Review said they’re similar!

“It is interesting to observe the conclusions of a different Cochrane review published last year (Anglemyer at al) which compared a range of study designs applied in various fields and concluded that, on average, “there is little evidence for significant effect estimate differences between observational studies and RCTs, regardless of specific observational study design”.

Well now, isn’t that interesting? The previous Cochrane Review specifically found that the 2 study types yield comparable results in terms of quality, but now this one says the cross-sectional ones aren’t good enough. As usual, Douglas Main ignores the previous one because it hurts his point. Admittedly, it would be nice if the Cochrane Review would apply more consistent standards in the selection and exclusion criteria to avoid confusion.


However, Dr. Payet has some criticisms to make of the Cochrane Review itself. It’s lack of proper qualification has been a godsend for cherry-picking anti-fluoridation propagandists:


Did you notice a certain pattern there? “Our confidence…is limited…” “We did not identify any evidence…” “There is insufficient information…” “The evidence is limited…” How in the world does Douglas Main turn that into “fluoridation doesn’t work!” As the saying goes, “The absence of evidence for something is not the same evidence for the absence of that something.”


Payet drives this point home in his conclusion:


So what’s the real take-home message of this particular Cochrane Review? Here’s all they really said: “Our exclusion criteria meant that only 9 studies were reviewed. Regardless of the quality of other studies done, we ignored them. Based on the extremely small study size and the strict criteria applied, all we can say is that more contemporary RCTs prospective studies are called for, because the ones available are old and might be biased.” That’s it! Main and his interviewees, however, go straight to, “OMG IT DOESN’T WORK WE SHOULD STOP IT NOW!” Perhaps this will make the point more clearly:
What-the-Cochrane-Review-Should-Have-Concluded


*Dr. Charles D. Payet has been a full-time practicing dentist in the city of Charlotte, North Carolina since graduating from the UNC Chapel Hill School of Dentistry in 1998. He blogs on the science and art of dentistry for all ages with a skeptical eye atwww.SmilesbyPayet.com and has recently published several articles on the safety and efficacy of fluoride in community water fluoridation, toothpaste, etc.
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July ’15 – NZ blogs sitemeter ranking

Why blog screen from PowerPoint

Image credit: Rachel Knowles – Successful blogging workshop


Big problems with Sitemeter

The problems with SiteMeter are still bad  this month. No data could be obtained for about 50 blogs using SiteMeter. People have also reported strange results. So if you wish to query the information in the table I suggest you check out the data in the SiteMeter pages.

I think some bloggers have removed their Sitemeters. I will go through and delete blogs that don’t’ show any remaining links to Sitemeter.

If you are using SiteMeter, and especially if you find you page isn’t included this month, I suggest you consider transferring to a more reliable counter like StatCounter. Have a look at the NZ Blog Rankings FAQs if you need help with this.


There are now over 300 blogs on the list, although I am weeding out those which are no longer active or have removed public access to sitemeters. (Let me know if I weed out yours by mistake, or get your stats wrong).

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 July 2015. 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

The bureaucratic solution to a problem

Sometimes satire is very close to the truth. Take this piece from The Shovel – Liberal Party Commits To Having 50% Women In Seats Shown On Camera By 2025:

parliament-women1-620x399

Tony Abbott says his party is serious about the advancement of women, and has set an ambitious target to have half of all seats shown on TV filled by women within five years.

“We are deeply committed to giving the impression that a high proportion of Liberal MPs are women,” Mr Abbott said.

“These are plum seats – not just any old seats. They’re right behind where the men and Julie Bishop stand when they’re giving a speech, so it’s not just a token gesture”.

He said women had an important role to play in the party. “The party’s women are crucial for the Federal Budget, for example. They’re on screen for the entire length of the budget speech, which is beamed to millions of Australians. They feature on the front page of the nation’s newspapers”.

A Liberal Party spokesperson said there was still work to be done to meet the target. “At the moment women make up 20% of Liberal MPs, and around 45% of those on camera, so we’re not quite there yet”.


So often on issues like these bureaucrats are interested only in appearances – not correcting the problem. This reminds me very much of the approach taken by Human Resources bureaucrats in dealing with the issue of laboratory safety in my earlier life when I was employed. They talked a lot about “signage.” To them the way to resolve (or appear to resolve) a safety issue was to put up a lot of signs!

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Fluoridation: “Sciencey” sounding claims ruled unacceptable

chesterfield-cigarettes-science-advert

Today, “scientific” claims of advertisers and anti-fluoride propagandists can be just as misleading

Again and again I find myself getting really annoyed at the way science is used opportunistically in advertising. We are continually bombarded with claims that the effectiveness of a product is “scientifically proven.” Or that “scientists tell us” something which supports a product. Then there are those ads where actors dress up in white lab coats and wander around a fictional, but photogenic, laboratory while giving us a fairy tale explanation of the mechanism which makes their product so effective. And this misrepresentation is widespread – involving products from cosmetics and toothpaste to fertilisers.

This advertising exploits the credibility of science and scientists as trustworthy experts. Hence the use of white lab coats and sciencey sounding terminology. Even the citation of scientific literature, studies, and trials – with the full knowledge that the target audience has no way of checking these citations.

Many countries have bodies regulating what advertisers can and can’t claim. In New Zealand we have the Advertising Standards Authority(ASA). Our ASA welcomes complaints about advertising and its rulings can lead to adverts being removed. The complaint procedure is being used by members of the public. In 2014 the ASA received 871 complaints about 672 adverts – up 10% and 12% respectively from 2013.

The Society for Science Based Healthcare publicises the complaint procedure and has made many complaints itself on products like homoeopathic treatments and magnetic mattress underlays. One of their members, Mark Honeychurch, created a tool for accessing information from the ASA complaint database which provides useful information.

It turns out that one of the most complained about organisations is Fluoride Free NZ (FFNZ) – a group campaigning against community water fluoridation. It ranks 13th in  the  organisations having the most successful complaints made against them.

Bottom-organisations-FFNZ-full-screen

The data also shows that a relatively high proportion of those complaints against FFNZ have been successful. That tells me that the complainants have been able to present good arguments to support their complaints.

Anti-fluoride campaigners are well known to claim scientific support for their case. But analysis of their claims shows them to be based on misrepresentations and distortion of the science. They are a classic example of advertisers who opportunistically, but dishonestly, use science to promote their products.

I think the misrepresentation and distortion of science are widespread in advertising and the propaganda from activist groups like FFNZ. At times, the problem seems so immense it seems impossible to counter it. So it is great to see groups like The Society for Science Based Healthcare, and the many people making similar complaints, having this sort of success.

On the other hand, perhaps consumers are developing a healthy scepticism about advertising claims. That is also a good thing, as long as that scepticism doesn’t lead to denigration of the authority of science as the best way of understanding the world and testing claims.

That would be throwing out the baby with the bath water.

See alsoFluoride Free NZ ranks 13th worst NZ organisation by ASA complaints

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Comparing the Cochrane and NZ Fluoridation Reviews

Sci Rev

New Zealand policy makers and health professionals should be wary about much of the current media comments on the Cochrane Fluoridation Review (Iheozor-Ejiofor 2015). Anti-fluoridation campaigners are misrepresenting it and distorting its findings. They are using cherry-picked quotes to make claims about the review which are just not true.

Some are even claiming (wrongly) that the Cochrane review findings conflict with this in the NZ Fluoridation Review (Eason et al., 2014). Or that, simply because it was published a few months after the NZ Review it somehow makes the NZ Review obsolete.

Review findings agree

Nothing could be further from the truth. The findings in the Cochrane Review do not conflict with those in the NZ  Review. And, because the Cochrane Review is much more limited than the NZ Review, policy makers and health professionals should not consider that as the only document required for their reading.

In particular, the Cochrane Review considered only questions of community water fluoridation (CWF) efficacy. It did not consider aspects related to health concerns which, of course, are always in the front of the minds of policy makers and health professionals.

I have done a side-by-side comparison of the two reviews and summarise their findings below

CWF efficacy

The Cochrane reviewers produced a quantitative estimate for the effect of CWF on dental decay, but only for children and used only studies satisfying their strict selection criteria (see Cochrane fluoridation review. I: Most research ignored). This unfortunately excluded more recent high-quality cross-sectional studies.

The NZ Reviewers did not produce an overall quantitative estimate but made more general conclusions.

Cochrane Review

NZ Fluoridation Review

Efficacy of CWF
“Data suggest that the introduction of water fluoridation resulted in a 35% reduction in decayed, missing or filled baby teeth and a 26% reduction in decayed, missing or filled permanent teeth. It also increased the percentage of children with no decay by 15%. These results indicate that water fluoridation is effective at reducing levels of tooth decay in both children’s baby and permanent teeth”. “Analysis of evidence from a large number of epidemiological studies and thorough systematic reviews has confirmed a beneficial effect of CWF on oral health throughout the lifespan. This includes relatively recent studies in the context of the overall reduced burden of caries that has resulted from the widespread use of topical fluoride products (e.g. toothpastes,  mouth rinses, and fluoride varnishes).”
Adult caries
No conclusions because of study selection limitations. “Although most studies of the effects of CWF have focused on benefits in children, caries
experience continues to accumulate with age, and CWF has also been found to help reduce the extent and severity of dental decay in adults, particularly with prolonged exposure. The long history of CWF around the world now means that many adults in late life have experienced a lifetime of fluoridation. The benefits for adult dental health include lower levels of root caries, and better tooth retention into old age.”
Socio-economic effects
No conclusions because of study selection limitations. “The burden of tooth decay is highest among the most deprived socioeconomic groups, and this is the segment of the population for which the benefits of CWF appear to be greatest. CWF appears to be most cost-effective in those communities that are most in need of improved oral health. In New Zealand, these include communities of low socioeconomic status, and those with a high proportion of children or Māori. A number of studies have suggested that the benefits of CWF are greatest among the most deprived socioeconomic groups, although the magnitude of the difference is uncertain.”
Effect of stopping fluoridation
No conclusions because of study selection limitations. “Stopping CWF leads to ~17% increase in caries experience”  cited from US Task Force on Community Preventive Services
Influence of fluoridated toothpaste, etc.
No conclusions because of study selection limitations. The beneficial effect of CWF on oral health is still shown in relatively recent studies illustrating the overall reduced burden of caries that has resulted from the widespread use of topical fluoride products (e.g. toothpastes,  mouth rinses, and fluoride varnishes). “In New Zealand, significant differences in decay rates between fluoridated and non-fluoridated communities continue to exist, despite the fact that the majority of people use fluoride toothpastes.”

Health issues related to CWF

Dental fluorosis is generally considered the only negative health results of CWF. Both Reviews did consider dental fluorosis, although the Cochrane review did not specifically compare fluoridated and unfluoridated areas – which is necessary to determine the effect of fluoridation on dental fluorosis prevalence. See Cochrane fluoridation review. III: Misleading section on dental fluorosis for a discussion of this and an estimate fo the effect of CWF on dental fluorosis calculated using the Cochrane data.

The Cochrane review did not consider any other health effects.

Cochrane Review

NZ Fluoridation Review

Dental Fluorosis
Only calculated effect of fluoride intake in dental fluorosis. The effect of CWF itself was not considered. However, this can be estimated by subtracting prevalence for unfluoridated region. These estimates indicate that dental fluorosis levels of aesthetic concern are similar in fluoridated and unfluoridated areas (see Cochrane fluoridation review. III: Misleading section on dental fluorosis).
.
“The prevalence of fluorosis of aesthetic concern is minimal in New Zealand, and is
not different between fluoridated and non-fluoridated communities, confirming that a substantial proportion of the risk is attributable to the intake of fluoride from sources other
than water (most notably, the swallowing of high-fluoride toothpaste by young children).
The current fluoridation levels therefore appear to be appropriate. It is important, however, that the chosen limit continues to protect the majority of high-exposure individuals.”
IQ effects
Not considered “We conclude that on the available evidence there is no appreciable effect on cognition arising from CWF.”
Cancer
Not considered “We conclude that on the available evidence there is no appreciable risk of cancer arising from CWF.”
Kidney
Not considered “Studies and systematic reviews have found no evidence that consumption of optimally fluoridated drinking water increases the risk of developing kidney disease. However, individuals with impaired kidney function experience higher/more prolonged fluoride exposure after
ingestion because of reduced urinary fluoride excretion, and those with end stage kidney
disease may be at greater risk of fluorosis.”

Conclusions

The Cochrane review is far more limited in its coverage than the NZ Fluoridation Review. It did not consider possible health effects (apart from dental fluorosis) which is an important aspect of the fluoridation controversy for health professionals and policy makers.

The two Reviews agree that CWF is effective for children, but the NZ Review also considered effectiveness for adults, the reduction of socioeconomic differences in oral health and effects of stopping fluoridation on tooth decay. It also considered more recent research than the Cochrane review, so was able to discuss possible reduction in the efficacy of CWF due to the use of fluoridated toothpaste in recent years.

The Cochrane review does not make the NZ Fluoridation  Review obsolete at all. Nor do its conclusions conflict with those of the New Zealand Review.

Policy makers and health professionals should pay attention to both reviews in making judgements of CWF efficacy, but will need to use the NZ Review for their judgements on possible health effects.

References

New Zealand Fluoridation Review:
Eason, C., & Elwood, JM. Seymour, Thomson, WM. Wilson, N. Prendergast, K. (2014). Health effects of water fluoridation : A review of the scientific evidence

Cochrane Fluoridation Review:
Iheozor-Ejiofor, Z., Worthington, HV., Walsh, T., O’Malley, L., Clarkson, JE., Macey, R., Alam, R., Tugwell, P., Welch, V., Glenny, A. (2015). Water fluoridation for the prevention of dental caries (Review). The Cochrane Library, (6).

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Rapid change in attitudes to marriage equality

marriage-equality

Click the image to go to the video (unfortunately I can’t embed the video here).

The video demonstrates “The Stunning 15-Year March to Marriage Equality Around the World.” And it certainly shows how rapid this change in community values has been.

I suppose many people will look at the map and feel they occupy the moral high ground because we are citizens of a country that has accepted marriage equality. The map certainly differentiates between those who have accepted and those who haven’t.

But the very rapidity of this change in community values is also a lesson. We should expect more countries to accept marriage equality in the near future. and secondly, we should be a bit humble and not make judgments on people and countries who have not yet accepted marriage equality.

After all, we were in that position a very short time ago.

Thanks to:  Same-sex marriage world map: Countries where gay unions are permitted after Supreme Court (VIDEO)..

http://c.brightcove.com/services/viewer/federated_f9?isVid=1&isUI=1