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pediatrics

Publication bias: big problem for children

Peter Gill
Last edited 6th May 2012

A recent study in the journal Pediatrics reported that only 29% of clinical studies in children have been published. This finding reinforces previous studies that there is significant publication bias in paediatric studies. These findings are a cause for serious concern.

What is publication bias? Essentially, it is the selected publication of studies based on the results, such as only publishing studies that demonstrate a drug works while not publishing studies that demonstrate harms.

Publication bias is a serious problem in healthcare and can have a large influence on treatment decisions by only providing limited information. Researchers have demonstrated substantial publication bias in certain areas such as the antidepressant medication reboxetine.

Several initiatives have been spearheaded to help reduce publication bias. The creation of open-access journals have shifted the focus from the importance of the results (as judged by a journal editorial committee) to the methodological rigour by which the study was completed.

But more importantly has been the creation of online trial registries, such as ClinicalTrials.gov launched in 2000. These registries serve as central databases of all the current and on-going clinical studies. Registration is optional, however in 2005 the ICMJE made registration of clinical trials as a pre-requisite of publication. Although this does not represent all journals, it sent a strong message of the importance of registration.

However despite the creation of trial registries, less than half of US based National Institute of Health (i.e. government) funded trials in children were registered on ClinicalTrials.gov. Another important finding was the lack of information included on the registries. One-third of all clinical studies terminated early did not provide any information about why they were stopped. The situation was similar for suspended studies with one quarter not providing information.

Were these studies stopped because of harms? Were the investigators no longer able to recruit children to enroll? Whatever the reason the studies were stopped, this information must be made public.

Registration of all clinical studies involving children must be made mandatory. This is the only way to minimise publication bias and increase the reporting of research. This would create massive industry uproar, but is it ethical to enroll children in a clinical study without having it publicly registered? At a minimum any trial that receives government funded must be registered.

However registration of studies is only one element of the formula. What about the dissemination of the results? Less than 10% of completed studies in children had results posted and publicly available. With the low publication rates of registered studies, and the even lower rate of posting results, how much information is still missing?

Indeed progress has been made to increase the quality and transparency of clinical studies in children but more is needed. We cannot assume that because trial registries exist that they are being used. Complacency must be replaced with compliance. It seems that more often than not, the little ones have the biggest problems.

The recent post on whether Christmas is bad for you inspired further questions on the evidence behind holiday season myths. There is a common misconception that poinsettias (Euphorbia pulcherrima for the botanists) are poisonous. Grandparents tell stories to new parents that they must be vigilant to ensure that children don’t ingest the plant’s leaves.

But what is the evidence?

A study published in 1996 in the American Journal of Emergency Medicine sought to provide an answer. The authors evaluated 849,575 plant exposures reported to the American Association of Poison Control Centers. Poinsettia exposures accounted for 22,793 cases, or nearly 3%, of which nearly all occurred in December and January. Not surprisingly, 94% of poinsettia exposures were in children.

But were they poisonous? No. None were fatal. In fact, only 4% of patients required treatment in a health care facility and fewer than 7% developed toxicity. Most reactions were mild - children that ingested leaves may experience diarrhea and vomiting or have an allergic reaction to the skin.

Poinsettias are not toxic. They don’t stalk family homes waiting for the opportune time to poison children with their attractive red leaves. Children that accidentally ingest poinsettia leaves rarely require treatment. In fact, the real concern is that they may be a choking hazard.

Well what are the real hazards around Christmas time? The Children's Hospital of Philadelphia website highlights the harms that children need to worry about. An unsuspecting culprit took the top spot: alcohol. Alcohol is a serious hazard in children that can lead to major health problems if ingested by children, even in small quantities. Be wary of leaving empty glasses around the house that could break and be ingested by children.

Similar to alcohol if you are in a cold enough climate, windshield washer fluid and antifreeze are serious hazards. The sweet tasting liquid that looks like Kool-Aid can lead to blindness, seizures, heart-rhythm changes and even death if ingested.

Other quintessential botanical Christmas symbols that are poisonous: holly. A handful of berries from the Illex opaca shrub can produce nausea, vomiting, diarrhea and drowsiness in children. The toxicity of kiss causing mistletoe is not supported by the evidence with most cases having a similar outcome as with poinsettia exposure. But with all substances, beware of large amounts.

Be on the look out for disc batteries (coin shaped circular ones) that can be a choking hazard if swallowed. If they become stuck in the esophagus or stomach, they can begin to leak their caustic contents and cause severe burns.

Irrespective of the hazard, most children swallow these objects when they are left unattended. When enjoying the holiday season this year, keep an eye on the curious children putting objects in their mouth and dispel the old urban myths that lack evidence. Happy Holidays.

Emergency contraception: emotion, evidence and bubble gum

Peter Gill
Last edited 18th December 2011

Earlier this year, the FDA recommended that emergency contraception, or Plan B, should be available without prescription to girls under 17 as it is currently available by prescription only to this age group. In an unprecedented move, the US Health and Human Services secretary Kathleen Sebelius vetoed the FDA's recommendation to make Plan B available without prescription to all women of childbearing age in the US. Mr. Obama said the secretary felt a 10- or 11-year-old should not be able to buy emergency contraception “alongside bubble gum or batteries."

What is Plan B or emergency contraception? Plan B is a pill that consists of the hormone progestin that works by preventing an egg from being fertilised. It must be used within 120 hours after unprotected sex, is safe and effective with few side effects and none dangerous.

Unlike some misconceptions, the availability of emergency contraception dose not change rates of sexual activity or increase the frequency of unprotected sex among adolescents.

Unintended pregnancies are an emotional and controversial issue, invoking deep-rooted religious, political and ideological beliefs. The US has one of the highest rates of unintended pregnancies with nearly half of all pregnancies unintended. In particular, adolescent birth rates in the US are much higher than rates in other developed countries.

Side stepping the issue of induced abortion, what is the effect of unintended pregnancy on women? A recent Lancet editorial discussed the results of a comprehensive review into the mental health outcomes of women after having an induced abortion. The key study finding was that having an unwanted pregnancy leads to an increased risk of mental health problems, not having an induced abortion.

The US should be leading the battle to reduce unintended pregnancies. Indeed the American Academy of Pediatrics (AAP) “encourages abstinence plus comprehensive sexuality education as the best way to help prevent unintended pregnancy and sexually transmitted diseases.” Further, they support the availability of emergency contraception, or Plan B, for adolescents.

Given that only 20-25% of health care providers discuss emergency contraception with adolescents, the restriction of Plan B to prescription only to adolescents under 17 seems a major barrier to access.

What is the likelihood that a 15-year-old who had unprotected sex is going to get a prescription for Plan B? She will be able to purchase acetominophen (i.e. Tylenol or Paracetamol) without a prescription, a medication that can potentially cause fatal liver damage and lead to liver failure if used inappropriately, yet she cannot purchase Plan B to prevent an unintended pregnancy.

Rather than rely on evidence, emotion wins. But the real loser are adolescents under 17 who may face life-long mental health problems. When emotion wins, we all lose.

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