BAD Science or BAD Science Journalism? – A Response to Daniel Lakens

10 02 2013

ResearchBlogging.orgTwo weeks ago  there was a hot debate among Dutch Tweeps on “bad science, bad science journalism and bad science communication“. This debate was started and fueled by different Dutch blog posts on this topic.[1,4-6]

A controversial post, with both fierce proponents and fierce opposition was the post by Daniel Lakens [1], an assistant professor in Applied Cognitive Psychology.

I was among the opponents. Not because I don’t like a new fresh point of view, but because of a wrong reasoning and because Daniel continuously compares apples and oranges.

Since Twitter debates can’t go in-depth and lack structure and since I cannot comment to his Google sites blog, I pursue my discussion here.

The title of Daniels post is (freely translated, like the rest of his post):

Is this what one calls good science?” 

In his post he criticizes a Dutch science journalist, Hans van Maanen, and specifically his recent column [2], where Hans discusses a paper published in Pediatrics [3].

This longitudinal study tested the Music Marker theory among 309 Dutch kids. The researchers gathered information about the kids’ favorite types of music and tracked incidents of “minor delinquency”, such as shoplifting or vandalism, from the time they were 12 until they reached age 16 [4]. The researchers conclude that liking music that goes against the mainstream (rock, heavy metal, gothic, punk, African American music, and electronic dance music) at age 12 is a strong predictor of future minor delinquency at 16, in contrast to chart pop, classic music, jazz.

The University press office send out a press release [5 ], which was picked up by news media [4,6] and one of the Dutch authors of this study,  Loes Keijsers,  tweeted enthusiastically: “Want to know whether a 16 year old adult will suffer from delinquency, than look at his music taste at age 12!”

According to Hans, Loes could have easily broadcasted (more) balanced tweets, likeMusic preference doesn’t predict shoplifting” or “12 year olds who like Bach keep quiet about shoplifting when 16.” But even then, Hans argues, the tweets wouldn’t have been scientifically underpinned either.

In column style Hans explains why he thinks that the study isn’t methodologically strong: no absolute numbers are given; 7 out of 11 (!) music styles are positively associated with delinquency, but these correlations are not impressive: the strongest predictor (Gothic music preference) can explain no more than 9%  of the variance in delinquent behaviour, which can include anything from shoplifting, vandalism, fighting, graffiti spraying, switching price tags.  Furthermore the risks of later “delinquent” behavior are small:  on a scale 1 (never) to 4 (4 times or more) the mean risk was 1,12. Hans also wonders whether it is a good idea to monitor kids with a certain music taste.

Thus Hans concludesthis study isn’t good science”. Daniel, however, concludes that Hans’ writing is not good science journalism.

First Daniel recalls he and other PhD’s took a course on how to peer review scientific papers. On basis of their peer review of a (published) article 90% of the students decided to reject it. The two main lessons learned by Daniel were:

  • It is easy to critize a scientific paper and grind it down. No single contribution to science (no single article) is perfect.
  • New scientific insights, although imperfect, are worth sharing, because they help to evolve science. *¹

According to Daniel science jounalists often make the same mistakes as the peer reviewing PhD-students: critisizing the individuel studies without a “meta-view” on science.

Peer review and journalism however are different things (apples and oranges if you like).

Peer review (with all its imperfections) serves to filter, check and to improve the quality of individual scientific papers (usually) before they are published  [10]. My papers that passed peer review, were generally accepted. Of course there were the negative reviewers, often  the ignorant ones, and the naggers, but many reviewers had critique that helped to improve my paper, sometimes substantially. As a peer reviewer myself I only try to separate the wheat from the chaff and to enhance the quality of the papers that pass.

Science journalism also has a filter function: it filters already peer reviewed scientific papers* for its readership, “the public” by selecting novel relevant science and translating the scientific, jargon-laded language, into language readers can understand and appreciate. Of course science journalists should put the publication into perspective (call it “meta”).

Surely the PhD-students finger exercise resembles the normal peer review process as much as peer review resembles science journalism.

I understand that pure nitpicking seldom serves a goal, but this rarely occurs in science journalism. The opposite, however, is commonplace.

Daniel disapproves Hans van Maanen’s criticism, because Hans isn’t “meta” enough. Daniel: “Arguing whether an effect size is small or mediocre is nonsense, because no individual study gives a good estimate of the effect size. You need to do more research and combine the results in a meta-analysis”.

Apples and oranges again.

Being “meta” has little to do with meta-analysis. Being meta is … uh … pretty meta. You could think of it as seeing beyond (meta) the findings of one single study*.

A meta-analysis, however, is a statistical technique for combining the findings from independent, but comparable (homogeneous) studies in order to more powerfully estimate the true effect size (pretty exact). This is an important, but difficult methodological task for a scientist, not a journalist. If a meta-analysis on the topic exist, journalists should take this into account, of course (and so should the researchers). If not, they should put the single study in broader perspective (what does the study add to existing knowledge?) and show why this single study is or is not well done?

Daniel takes this further by stating that “One study is no study” and that journalists who simply echo the press releases of a study ànd journalists who just amply criticizes only single publication (like Hans) are clueless about science.

Apples and oranges! How can one lump science communicators (“media releases”), echoing journalists (“the media”) and critical journalists together?

I see more value in a critical analysis than a blind rejoicing of hot air. As long as the criticism guides the reader to appreciate the study.

And if there is just one single novel study, that seems important enough to get media attention, shouldn’t we judge the research on its own merits?

Then Daniel asks himself: “If I do criticize those journalists, shouldn’t I criticize those scientists who published just a single study and wrote a press release about it? “

His conclusion? “No”.

Daniel explains: science never provides absolute certainty, at the most the evidence is strong enough to state what is likely true. This can only be achieved by a lot of research by different investigators. 

Therefore you should believe in your ideas and encourage other scientists to pursue your findings. It doesn’t help when you say that music preference doesn’t predict shoplifting. It does help when you use the media to draw attention to your research. Many researchers are now aware of the “Music Marker Theory”. Thus the press release had its desired effect. By expressing a firm belief in their conclusions, they encourage other scientists to spend their sparse time on this topic. These scientists will try to repeat and falsify the study, an essential step in Cumulative Science. At a time when science is under pressure, scientists shouldn’t stop writing enthusiastic press releases or tweets. 

The latter paragraph is sheer nonsense!

Critical analysis of one study by a journalist isn’t what undermines the  public confidence in science. Rather it’s the media circus, that blows the implications of scientific findings out of proportion.

As exemplified by the hilarious PhD Comic below research results are propagated by PR (science communication), picked up by media, broadcasted, spread via the internet. At the end of the cycle conclusions are reached, that are not backed up by (sufficient) evidence.

PhD Comics – The news Cycle

Daniel is right about some things. First one study is indeed no study, in the sense that concepts are continuously tested and corrected: falsification is a central property of science (Popper). He is also right that science doesn’t offer absolute certainty (an aspect that is often not understood by the public). And yes, researchers should believe in their findings and encourage other scientists to check and repeat their experiments.

Though not primarily via the media. But via the normal scientific route. Good scientists will keep track of new findings in their field anyway. Suppose that only findings that are trumpeted in the media would be pursued by other scientists?

7-2-2013 23-26-31 media & science

And authors shouldn’t make overstatements. They shouldn’t raise expectations to a level which cannot be met. The Dutch study only shows weak associations. It simply isn’t true that the Dutch study allows us to “predict” at an individual level if a 12 year old will “act out” at 16.

This doesn’t help lay-people to understand the findings and to appreciate science.

The idea that media should just serve to spotlight a paper, seems objectionable to me.

Going back to the meta-level: what about the role of science communicators, media, science journalists and researchers?

According to Maarten Keulemans, journalist, we should just get rid of all science communicators as a layer between scientists and journalists [7]. But Michel van Baal [9] and Roy Meijer[8] have a point when they say that  journalists do a lot PR-ing too and they should do better than to rehash news releases.*²

Now what about Daniel criticism of van Maanen? In my opinion, van Maanen is one of those rare critical journalists who serve as an antidote against uncritical media diarrhea (see Fig above). Comparable to another lone voice in the media: Ben Goldacre. It didn’t surprise me that Daniel didn’t approve of him (and his book Bad Science) either [11]. 

Does this mean that I find Hans van Maanen a terrific science journalist? No, not really. I often agree with him (i.e. see this post [12]). He is one of those rare journalists who has real expertise in research methodology . However, his columns don’t seem to be written for a large audience: they seem too complex for most lay people. One thing I learned during a scientific journalism course, is that one should explain all jargon to one’s audience.

Personally I find this critical Dutch blog post[13] about the Music Marker Theory far more balanced. After a clear description of the study, Linda Duits concludes that the results of the study are pretty obvious, but that the the mini-hype surrounding this research is caused by the positive tone of the press release. She stresses that prediction is not predetermination and that the musical genres are not important: hiphop doesn’t lead to criminal activity and metal not to vandalism.

And this critical piece in Jezebel [14],  reaches far more people by talking in plain, colourful language, hilarious at times.

It also a swell title: “Delinquents Have the Best Taste in Music”. Now that is an apt conclusion!


*¹ Since Daniel doesn’t refer to  open (trial) data access nor the fact that peer review may , I ignore these aspects for the sake of the discussion.

*² Coincidence? Keulemans has covered  the music marker study quite uncritically (positive).

Photo Credits


  1. Daniel Lakens: Is dit nou goede Wetenschap? - Jan 24, 2013 (
  2. Hans van Maanen: De smaak van boefjes in de dop,De Volkskrant, Jan 12, 2013 (
  3. ter Bogt, T., Keijsers, L., & Meeus, W. (2013). Early Adolescent Music Preferences and Minor Delinquency PEDIATRICS DOI: 10.1542/peds.2012-0708
  4. Lindsay Abrams: Kids Who Like ‘Unconventional Music’ More Likely to Become Delinquent, the Atlantic, Jan 18, 2013
  5. Muziekvoorkeur belangrijke voorspeller voor kleine criminaliteit. Jan 8, 2013 (
  6. Maarten Keulemans: Muziek is goede graadmeter voor puberaal wangedrag - De Volkskrant, 12 januari 2013  (
  7. Maarten Keulemans: Als we nou eens alle wetenschapscommunicatie afschaffen? – Jan 23, 2013 (
  8. Roy Meijer: Wetenschapscommunicatie afschaffen, en dan? – Jan 24, 2013 (
  9. Michel van Baal. Wetenschapsjournalisten doen ook aan PR – Jan 25, 2013 ((
  10. What peer review means for science (
  11. Daniel Lakens. Waarom raadde Maarten Keulemans me Bad Science van Goldacre aan? Oct 25, 2012
  12. Why Publishing in the NEJM is not the Best Guarantee that Something is True: a Response to Katan - Sept 27, 2012 (
  13. Linda Duits: Debunk: worden pubers crimineel van muziek? (
  14. Lindy west: Science: “Delinquents Have the Best Taste in Music” (

Friday Foolery #54 The Best 404 Message ever?

25 01 2013


Somebody send me a direct message via Twitter, asking me if he had missed any posts. Sorting his Google Reader feeds, he saw this blog was last updated October.

And he is right :(.

Just to assure you that this blog is not dead, but hibernating*, I would like to link to perhaps the BEST 404 message ever.

This 404 message aptly shows where you can turn to when you “Lost your sense of direction” at the ASRM (American Society for Reproductive Medicine) website.


Hattip: Bora Zivkovic (@BoraZ), @palmd) and Rebecca Weinberg (@sciliz)

* I have little spare time (and energy) at the moment to write my “usual” long exhaustive posts. Sorry. But I will come back!

Why Publishing in the NEJM is not the Best Guarantee that Something is True: a Response to Katan

27 10 2012

ResearchBlogging.orgIn a previous post [1] I reviewed a recent  Dutch study published in the New England Journal of Medicine (NEJM [2] about the effects of sugary drinks on the body mass index of school children.

The study got widely covered by the media. The NRC, for which the main author Martijn Katan works as a science columnist,  columnist, spent  two full (!) pages on the topic -with no single critical comment-[3].
As if this wasn’t enough, the latest column of Katan again dealt with his article (text freely available at[4].

I found Katan’s column “Col hors Catégorie” [4] quite arrogant, especially because he tried to belittle a (as he called it) “know-it-all” journalist who criticized his work  in a rivaling newspaper. This wasn’t fair, because the journalist had raised important points [5, 1] about the work.

The piece focussed on the long road of getting papers published in a top journal like the NEJM.
Katan considers the NEJM as the “Tour de France” among  medical journals: it is a top achievement to publish in this paper.

Katan also states that “publishing in the NEJM is the best guarantee something is true”.

I think the latter statement is wrong for a number of reasons.*

  1. First, most published findings are false [6]. Thus journals can never “guarantee”  that published research is true.
    Factors that  make it less likely that research findings are true include a small effect size,  a greater number and lesser preselection of tested relationships, selective outcome reporting, the “hotness” of the field (all applying more or less to Katan’s study, he also changed the primary outcomes during the trial[7]), a small study, a great financial interest and a low pre-study probability (not applicable) .
  2. It is true that NEJM has a very high impact factor. This is  a measure for how often a paper in that journal is cited by others. Of course researchers want to get their paper published in a high impact journal. But journals with high impact factors often go for trendy topics and positive results. In other words it is far more difficult to publish a good quality study with negative results, and certainly in an English high impact journal. This is called publication bias (and language bias) [8]. Positive studies will also be more frequently cited (citation bias) and will more likely be published more than once (multiple publication bias) (indeed, Katan et al already published about the trial [9], and have not presented all their data yet [1,7]). All forms of bias are a distortion of the “truth”.
    (This is the reason why the search for a (Cochrane) systematic review must be very sensitive [8] and not restricted to core clinical journals, but even include non-published studies: for these studies might be “true”, but have failed to get published).
  3. Indeed, the group of Ioannidis  just published a large-scale statistical analysis[10] showing that medical studies revealing “very large effects” seldom stand up when other researchers try to replicate them. Often studies with large effects measure laboratory and/or surrogate markers (like BMI) instead of really clinically relevant outcomes (diabetes, cardiovascular complications, death)
  4. More specifically, the NEJM does regularly publish studies about pseudoscience or bogus treatments. See for instance this blog post [11] of ScienceBased Medicine on Acupuncture Pseudoscience in the New England Journal of Medicine (which by the way is just a review). A publication in the NEJM doesn’t guarantee it isn’t rubbish.
  5. Importantly, the NEJM has the highest proportion of trials (RCTs) with sole industry support (35% compared to 7% in the BMJ) [12] . On several occasions I have discussed these conflicts of interests and their impact on the outcome of studies ([13, 14; see also [15,16] In their study, Gøtzsche and his colleagues from the Nordic Cochrane Centre [12] also showed that industry-supported trials were more frequently cited than trials with other types of support, and that omitting them from the impact factor calculation decreased journal impact factors. The impact factor decrease was even 15% for NEJM (versus 1% for BMJ in 2007)! For the journals who provided data, income from the sales of reprints contributed to 3% and 41% of the total income for BMJ and The Lancet.
    A recent study, co-authored by Ben Goldacre (MD & science writer) [17] confirms that  funding by the pharmaceutical industry is associated with high numbers of reprint ordersAgain only the BMJ and the Lancet provided all necessary data.
  6. Finally and most relevant to the topic is a study [18], also discussed at Retractionwatch[19], showing that  articles in journals with higher impact factors are more likely to be retracted and surprise surprise, the NEJM clearly stands on top. Although other reasons like higher readership and scrutiny may also play a role [20], it conflicts with Katan’s idea that  “publishing in the NEJM is the best guarantee something is true”.

I wasn’t aware of the latter study and would like to thank drVes and Ivan Oranski for responding to my crowdsourcing at Twitter.


  1. Sugary Drinks as the Culprit in Childhood Obesity? a RCT among Primary School Children (
  2. de Ruyter JC, Olthof MR, Seidell JC, & Katan MB (2012). A trial of sugar-free or sugar-sweetened beverages and body weight in children. The New England journal of medicine, 367 (15), 1397-406 PMID: 22998340
  3. NRC Wim Köhler Eén kilo lichter.NRC | Zaterdag 22-09-2012 (
  4. Martijn Katan. Col hors Catégorie [Dutch], (published in de NRC,  (20 oktober)(
  5. Hans van Maanen. Suiker uit fris, De Volkskrant, 29 september 2012 (freely accessible at
  6. Ioannidis, J. (2005). Why Most Published Research Findings Are False PLoS Medicine, 2 (8) DOI: 10.1371/journal.pmed.0020124
  7. Changes to the protocol
  8. Publication Bias. The Cochrane Collaboration open learning material (
  9. de Ruyter JC, Olthof MR, Kuijper LD, & Katan MB (2012). Effect of sugar-sweetened beverages on body weight in children: design and baseline characteristics of the Double-blind, Randomized INtervention study in Kids. Contemporary clinical trials, 33 (1), 247-57 PMID: 22056980
  10. Pereira, T., Horwitz, R.I., & Ioannidis, J.P.A. (2012). Empirical Evaluation of Very Large Treatment Effects of Medical InterventionsEvaluation of Very Large Treatment Effects JAMA: The Journal of the American Medical Association, 308 (16) DOI: 10.1001/jama.2012.13444
  11. Acupuncture Pseudoscience in the New England Journal of Medicine (
  12. Lundh, A., Barbateskovic, M., Hróbjartsson, A., & Gøtzsche, P. (2010). Conflicts of Interest at Medical Journals: The Influence of Industry-Supported Randomised Trials on Journal Impact Factors and Revenue – Cohort Study PLoS Medicine, 7 (10) DOI: 10.1371/journal.pmed.1000354
  13. One Third of the Clinical Cancer Studies Report Conflict of Interest (
  14. Merck’s Ghostwriters, Haunted Papers and Fake Elsevier Journals (
  15. Lexchin, J. (2003). Pharmaceutical industry sponsorship and research outcome and quality: systematic review BMJ, 326 (7400), 1167-1170 DOI: 10.1136/bmj.326.7400.1167
  16. Smith R (2005). Medical journals are an extension of the marketing arm of pharmaceutical companies. PLoS medicine, 2 (5) PMID: 15916457 (free full text at PLOS)
  17. Handel, A., Patel, S., Pakpoor, J., Ebers, G., Goldacre, B., & Ramagopalan, S. (2012). High reprint orders in medical journals and pharmaceutical industry funding: case-control study BMJ, 344 (jun28 1) DOI: 10.1136/bmj.e4212
  18. Fang, F., & Casadevall, A. (2011). Retracted Science and the Retraction Index Infection and Immunity, 79 (10), 3855-3859 DOI: 10.1128/IAI.05661-11
  19. Is it time for a Retraction Index? (
  20. Agrawal A, & Sharma A (2012). Likelihood of false-positive results in high-impact journals publishing groundbreaking research. Infection and immunity, 80 (3) PMID: 22338040


* Addendum: my (unpublished) letter to the NRC

Tour de France.
Nadat het NRC eerder 2 pagina’ s de loftrompet over Katan’s nieuwe studie had afgestoken, vond Katan het nodig om dit in zijn eigen column dunnetjes over te doen. Verwijzen naar je eigen werk mag, ook in een column, maar dan moeten wij daar als lezer wel wijzer van worden. Wat is nu de boodschap van dit stuk “Col hors Catégorie“? Het beschrijft vooral de lange weg om een wetenschappelijke studie gepubliceerd te krijgen in een toptijdschrift, in dit geval de New England Journal of Medicine (NEJM), “de Tour de France onder de medische tijdschriften”. Het stuk eindigt met een tackle naar een journalist “die dacht dat hij het beter wist”. Maar ach, wat geeft dat als de hele wereld staat te jubelen? Erg onsportief, omdat die journalist (van Maanen, Volkskrant) wel degelijk op een aantal punten scoorde. Ook op Katan’s kernpunt dat een NEJM-publicatie “de beste garantie is dat iets waar is” valt veel af te dingen. De NEJM heeft inderdaad een hoge impactfactor, een maat voor hoe vaak artikelen geciteerd worden. De NEJM heeft echter ook de hoogste ‘artikelterugtrekkings’ index. Tevens heeft de NEJM het hoogste percentage door de industrie gesponsorde klinische trials, die de totale impactfactor opkrikken. Daarnaast gaan toptijdschriften vooral voor “positieve resultaten” en “trendy onderwerpen”, wat publicatiebias in de hand werkt. Als we de vergelijking met de Tour de France doortrekken: het volbrengen van deze prestigieuze wedstrijd garandeert nog niet dat deelnemers geen verboden middelen gebruikt hebben. Ondanks de strenge dopingcontroles.

Silly Sunday #52 Online Education Sites: and the Spam Goes on.

14 10 2012

On many occasions  (hereherehere and here [1-4), I have warned against top 50 and 100 lists made by online education sites, like,

They are no more than splogs and link bait scams. Thus please don’t give them credit by linking to their sites.

I have also mentioned that people affiliated with these sites sometimes offer to write guest posts. Or they ask me to place an infographic.

Apparently they don’t do a lot of research. The post don’t really fit the topic of this blog and the writers don’t seem aware of my critical posts in the pasts.

Nevertheless, the number of requests keeps on growing. Sometimes I get 4-5 a day. Really ridiculous…

They don’t seem discouraged by my lack of response.

The letters are usually quite impersonal (they just found a wordpress-tag for instance).


Hey ,


While doing research  for an online educational resource I write for, I ran across your blog and thought you may be interested in an idea for a post I have been thinking about.

The fate of schools in California is tied to the financial health of the state and because of years of economic downturn and recession, the state can no longer support the schools and the price of tuition is skyrocketing. This is making attending college considerably more difficult for many qualified applicants.

I would love to write about this for your blog. Let me know if you’re interested and I will send you a full outline.



Lately I’m also informed about dead links at my blog. How kind. Three guesses which link is offered instead…..


Hi Laika Spoetnik,

I came across your website and wanted to notify you about a broken link on your page in case you weren’t aware of it. The link on which links to is no longer working. I’ve included a link to a useful page on Members of Congress that you could replace the broken link with if you’re interested in updating your website. Thanks for providing a great resource!

Link: http://www. onlinebachelordegreeprograms . com / resources / bachelor-of-arts-in-political-science-congress /
(spaces added)

Alexandra Sawyer


p.s. ( as far as I know I never linked to visi com, and 2009/6 is not a single post, but many..)


  1. Vanity is the Quicksand of Reasoning: Beware of Top 100 and 50 lists! (
  2. Beware of Top 50 “Great Tools to Double Check your Doctor” or whatever Lists. ((
  3. Even the Scientific American Blog Links to Spammy Online Education Affiliate Sites… (
  4. Health and Science Twitter & Blog Top 50 and 100 Lists. How to Separate the Wheat from the Chaff. (


Sugary Drinks as the Culprit in Childhood Obesity? a RCT among Primary School Children

24 09 2012 Childhood obesity is a growing health problem. Since 1980, the proportion of overweighted children has almost tripled in the USA:  nowadays approximately 17% of children and adolescents are obese.  (Source: [6])

Common sense tells me that obesity is the result of too high calory intake without sufficient physical activity.” - which is just what the CDC states. I’m not surprised that the CDC also mentions the greater availability of high-energy-dense foods and sugary drinks at home and at school as main reasons for the increased intake of calories among children.

In my teens I already realized that sugar in sodas were just “empty calories” and I replaced tonic and cola by low calory  Rivella (and omitted sugar from tea). When my children were young I urged the day care to restrain from routinely giving lemonade (often in vain).

I was therefore a bit surprised to notice all the fuss in the Dutch newspapers [NRC] [7] about a new Dutch study [1] showing that sugary drinks contributed to obesity. My first reaction was “Duhhh?!…. so what?”.

Also, it bothered me that the researchers had performed a RCT (randomized controlled trial) in kids giving one half of them sugar-sweetened drinks and the other half sugar-free drinks. “Is it ethical to perform such a scientific “experiment” in healthy kids?”, I wondered, “giving more than 300 kids 14 kilo sugar over 18 months, without them knowing it?”

But reading the newspaper and the actual paper[1], I found that the study was very well thought out. Also ethically.

It is true that the association between sodas and weight gain has been shown before. But these studies were either observational studies, where one cannot look at the effect of sodas in isolation (kids who drink a lot of sodas often eat more junk food and watch more television: so these other life style aspects may be the real culprit) or inconclusive RCT’s (i.e. because of low sample size). Weak studies and inconclusive evidence will not convince policy makers, organizations and beverage companies (nor schools) to take action.

As explained previously in The Best Study Design… For Dummies [8] the best way to test whether an intervention has a health effect is to do a  double blind RCT, where the intervention (in this case: sugary drinks) is compared to a control (drinks with artificial sweetener instead of sugar) and where the study participants, and direct researchers do not now who receives the  actual intervention and who the phony one.

The study of Katan and his group[1] was a large, double blinded RCT with a long follow-up (18 months). The researchers recruited 641 normal-weight schoolchildren from 8 primary schools.

Importantly, only children were included in the study that normally drank sugared drinks at school (see announcement in Dutch). Thus participation in the trial only meant that half of the children received less sugar during the study-period. The researchers would have preferred drinking water as a control, but to ensure that the sugar-free and sugar-containing drinks tasted and looked essentially the same they used an artificial sweetener as a control.

The children drank 8 ounces (250 ml) of a 104-calorie sugar-sweetened or no-calorie sugar-free fruit-flavoured drink every day during 18 months.  Compliance was good as children who drank the artificially sweetened beverages had the expected level of urinary sucralose (sweetener).

At the end of the study the kids in the sugar-free group gained a kilo less weight than their peers. They also had a significant lower BMI-increase and gained less body fat.

Thus, according to Katan in the Dutch newspaper NRC[7], “it is time to get rid of the beverage vending machines”. (see NRC [6]).

But does this research really support that conclusion and does it, as some headlines state [9]: “powerfully strengthen the case against soda and other sugary drinks as culprits in the obesity epidemic?”

Rereading the paper I wondered as to the reasons why this study was performed.

If the trial was meant to find out whether putting children on artificially sweetened beverages (instead of sugary drinks) would lead to less fat gain, then why didn’t the researchers do an  intention to treat (ITT) analysis? In an ITT analysis trial participants are compared–in terms of their final results–within the groups to which they were initially randomized. This permits the pragmatic evaluation of the benefit of a treatment policy.
Suppose there were more dropouts in the intervention group, that might indicate that people had a reason not to adhere to the treatment. Indeed there were many dropouts overall: 26% of the children had stopped consuming the drinks, 29% from the sugar-free group, and 22% from the sugar group.
Interestingly, the majority of the children who stopped drinking the cans because they no longer liked the drink (68/94 versus 45/70 dropouts in the sugar-free versus the sugar group).
Ànd children who correctly assumed that the sweetened drinks were “artificially sweetened” was 21% higher than expected by chance (correct identification was 3% lower in the sugar group).
Did some children stop using the non-sugary drinks because they found the taste less nice than usual or artificial? Perhaps.

This  might indicate that replacing sugar-drinks by artificially sweetened drinks might not be as effective in “practice”.

Indeed most of the effect on the main outcome, the differences in BMI-Z score (the number of standard deviations by which a child differs from the mean in the Netherland for his or her age or sex) was “strongest” after 6 months and faded after 12 months.

Mind you, the researchers did neatly correct for the missing data by multiple imputation. As long as the children participated in the study, their changes in body weight and fat paralleled those of children who finished the study. However, the positive effect of the earlier use of non-sugary drinks faded in children who went back to drinking sugary drinks. This is not unexpected, but it underlines the point I raised above: the effect may be less drastic in the “real world”.

Another (smaller) RCT, published in the same issue of the NEJM [2](editorial in[4]), aimed to test the effect of an intervention to cut the intake of sugary drinks in obese adolescents. The intervention (home deliveries of bottled water and diet drinks for one year) led to a significant reduction in mean BMI (body mass index), but not in percentage body fat, especially in Hispanic adolescents. However at one year follow up (thus one year after the intervention had stopped) the differences between the groups evaporated again.

But perhaps the trial was “just” meant as a biological-fysiological experiment, as Hans van Maanen suggested in his critical response in de Volkskrant[10].

Indeed, the data actually show that sugar in drinks can lead to a greater increase in obesity-related parameters (and vice versa). [avoiding the endless fructose-glucose debate [11].

In the media, Katan stresses the mechanistic aspects too. He claims that children who drank the sweetened drinks, didn’t compensate for the lower intake of sugars by eating more. In the NY-times he is cited as follows[12]: “When you change the intake of liquid calories, you don’t get the effect that you get when you skip breakfast and then compensate with a larger lunch…”

This seems a logic explanation, but I can’t find any substatation in the article.

Still “food intake of the children at lunch time, shortly after the morning break when the children have consumed the study drinks”, was a secondary outcome in the original protocol!! (see the nice comparison of the two most disparate descriptions of the trial design at [5], partly shown in the figure below).

“Energy intake during lunchtime” was later replaced by a “sensory evaluation” (with questions like: “How satiated do you feel?”). The results, however were not reported in their current paper. That is also true for a questionnaire about dental health.

Looking at the two protocol versions I saw other striking differences. At 2009_05_28, the primary outcomes of the study are the children’s body weight (BMI z-score),waist circumference (replaced by waist to height), skin folds and bioelectrical impedance.
The latter three become secondary outcomes in the final draft. Why?

Click to enlarge (source [5])

It is funny that although the main outcome is the BMI z score, the authors mainly discuss the effects on body weight and body fat in the media (but perhaps this is better understood by the audience).

Furthermore, the effect on weight is less then expected: 1 kilo instead of 2,3 kilo. And only a part is accounted for by loss in body fat: -0,55 kilo fat as measured by electrical impedance and -0,35 kilo as measured by changes in skinfold thickness. The standard deviations are enormous.

Look for instance at the primary end point (BMI z score) at 0 and 18 months in both groups. The change in this period is what counts. The difference in change between both groups from baseline is -0,13, with a P value of 0.001.

(data are based on the full cohort, with imputed data, taken from Table 2)

Sugar-free group : 0.06±1.00  [0 Mo]  –> 0.08±0.99 [18 Mo] : change = 0.02±0.41  

Sugar-group: 0.01±1.04  [0 Mo]  –> 0.15±1.06 [18 Mo] : change = 0.15±0.42 

Difference in change from baseline: −0.13 (−0.21 to −0.05) P = 0.001

Looking at these data I’m impressed by the standard deviations (replaced by standard errors in the somewhat nicer looking fig 3). What does a value of 0.01 ±1.04 represent? There is a looooot of variation (even though BMI z is corrected for age and sex). Although no statistical differences were found for baseline values between the groups the “eyeball test” tells me the sugar- group has a slight “advantage”. They seem to start with slightly lower baseline values (overall, except for body weight).

Anyway, the changes are significant….. But significance isn’t identical to relevant.

At a second look the data look less impressive than the media reports.

Another important point, raised by van Maanen[10], is that the children’s weight increases more in this study than in the normal Dutch population. 6-7 kilo instead of 3 kilo.

In conclusion, the study by the group of Katan et al is a large, unique, randomized trial, that looked at the effects of replacement of sugar by artificial sweeteners in drinks consumed by healthy school children. An effect was noticed on several “obesity-related parameters”, but the effects were not large and possibly don’t last after discontinuation of the trial.

It is important that a single factor, the sugar component in beverages is tested in isolation. This shows that sugar itself “does matter”. However, the trial does not show that sugary drinks are the main obesity  factor in childhood (as suggested in some media reports).

It is clear that the investigators feel very engaged, they really want to tackle the childhood obesity problem. But they should separate the scientific findings from common sense.

The cans fabricated for this trial were registered under the trade name Blikkie (Dutch for “Little Can”). This was to make sure that the drinks would never be sold by smart business guys using the slogan: “cans which have scientifically been proven to help to keep your child lean and healthy”.[NRC]

Still soft drink stakeholders may well argue that low calory drinks are just fine and that curbing sodas is not the magic bullet.

But it is a good start, I think.

Photo credits Cola & Obesity:  Melliegrunt Flikr [CC]

  1. de Ruyter JC, Olthof MR, Seidell JC, & Katan MB (2012). A Trial of Sugar-free or Sugar-Sweetened Beverages and Body Weight in Children. The New England journal of medicine PMID: 22998340
  2. Ebbeling CB, Feldman HA, Chomitz VR, Antonelli TA, Gortmaker SL, Osganian SK, & Ludwig DS (2012). A Randomized Trial of Sugar-Sweetened Beverages and Adolescent Body Weight. The New England journal of medicine PMID: 22998339
  3. Qi Q, Chu AY, Kang JH, Jensen MK, Curhan GC, Pasquale LR, Ridker PM, Hunter DJ, Willett WC, Rimm EB, Chasman DI, Hu FB, & Qi L (2012). Sugar-Sweetened Beverages and Genetic Risk of Obesity. The New England journal of medicine PMID: 22998338
  4. Caprio S (2012). Calories from Soft Drinks – Do They Matter? The New England journal of medicine PMID: 22998341
  5. Changes to the protocol
  6. Overweight and Obesity: Childhood obesity facts  and A growing problem (
  7. NRC Wim Köhler Eén kilo lichter.NRC | Zaterdag 22-09-2012 (
  8.  The Best Study Design… For Dummies (
  9. Studies point to sugary drinks as culprits in childhood obesity – CTV News (
  10. Hans van Maanen. Suiker uit fris, De Volkskrant, 29 september 2012 (freely accessible at
  11. Sugar-Sweetened Beverages, Diet Coke & Health. Part I. (
  12. Roni Caryn Rabina. Avoiding Sugared Drinks Limits Weight Gain in Two Studies. New York Times, September 21, 2012

#EAHIL2012 CEC 1: Drupal for Librarians

5 07 2012

This week I’m blogging at (and mostly about) the 13th EAHIL conference in Brussels. EAHIL stands for European Association for Health Information and Libraries.

I already blogged about the second Continuing Education Course (CEC) I followed, but I followed a continuing education course at Mondays, one day earlier. That session was led by Patrice Chalon, who is a Knowledge Manager at KCE – Belgian Health Care Knowledge Centre.

The first part was theoretical and easy to follow. Unfortunately there were quite a few mishaps with the practical part (some people could not install the program via the USB-stick, parts of the website were deleted and the computers were slow), but the entire session was instructive anyway. Even though I was about the only person (of 6) lacking CMS or HTML knowledge (but rereading the course abstract I now realize that was a prerequisite….)

Drupal is a freely available, easy to use,  modular content management system (CMS), for which you don’t need to have extensive programming (or HTML) experience.

Drupal was created by a Belgium student (Dries Buytaert) in 2000. It evolved from (small news site with build-in web board to share news among friends)  to Drupal (pronounced as “droo-puhl”, derived from the English pronunciation of the Dutch word “Druppel” which means “drop”). The purpose was to enable others to use and extend the experimentation platform so that more people could develop it further. is a well established and active community with over 630,000 subscribed members.

This web application makes use of PHP as a programming language and MySQL as a database backend.

In Drupal every “page” is a node. You can define as many nodes as you need (news, page, event etc) and create “child” pages if you like (and move them to another parent page if necessary).

The editing function is easy: you can easily edit the format without needing HTML (looks quite like WordPress) and add files as if were email. Therefore it could easily have a wiki function as well.

Drupal is fitted with a very good taxonomy system. This helps to organize nodes and menus.

Nodes, account registration and maintenance, menu management, and system administration all are basic features of  the standard release of Drupal, known as Drupal core.

But thanks to the large community, Drupal benefits from thousands of third party modules, to tailor Drupal to your needs. When choosing modules it is important to check for longevity (are modules still being adapted for new Drupal releases, how many downloads are there: the more downloads the more popular the module, the more likely the module is going to stay).

There are also different themes.

Drupal is used a lot by libraries and libraries in turn have developed specific modules apt to use for library-purposes.

The view-module enables you to provide a view of the metadata and you can use metadata as a filter to create lists. Patrick was very enthusiastic about the bibliographic function (“the ENDNOTE within the context management system). He showed that it was very easy to import and search for bibliographic records (and metadata) from PubMed, Google Scholar etc (and maintain correct links over time), i.e. just enter the PMID, DOI lookup etc. Keywords like MeSH are loaded correctly.

Forgive me if I don’t remember (and even may be wrong about) the technical details, but it really looked like a great tool with many possible forms of  uses.

If you need more information you can contact Patrick (Twitter: @pchalon) or consult Drupal and especially the Drupal Group “Libraries”  and Drupalib.

And as said, there is a large active community. For Drupal’s motto is “Come for the software, stay for the community.”

Examples of Drupal Websites: The new face of the Cochrane was created by its webmaster Chris Mavergames, and it is far more inviting to read and more interactive then it’s boring predecessor. As a matter of fact it was Chris’ enthusiasm about Drupal and the new looks of the Cochrane site which raised my interest into Drupal. Chris has a website about Drupal (& web development, linked data & information architecture in general) and a Twitter list of Drupal folks you can follow.

Another example is, created by Patrick. Here is a presentation by Patrick that shows more details about this website (and Drupal’s versatility to create library websites).

This blogpost is largely based on the comprehensive course notes of Patrick Chalon’s “Drupal for Librarians” (CC), supplemented with my own notes.


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