Several articles in Issue #5, 2015 of the International Journal of Epidemiology report on a debate that has been ignited about deworming programs in schools. The editorial summarizes the coverage in this issue " The World Health Organization and other international agencies promote deworming as a means of improving nutritional status, cognition and school attendance and thereby promoting economic development, largely on the basis of a single study in Kenya published a decade ago, augmented by a study from 1910 and an unpublished report of a follow-up of the Kenya study. In this issue of IJE we publish re-analyses of the influential Miguel and Kremer paper, a response by these authors and a commentary by Garner and others. The upshot of the re-analyses is that there may be a small effect of deworming on school attendance but no clear effect on examination performance. A 2015 update of a Cochrane review on the effects of deworming assessed in randomized controlled trials found no strong evidence of effects on nutritional status, haemoglobin levels, school attendance or exam performance. A so-called ‘worm wars’ for and against continuing current deworming policy in light of this new evidence has been declared, with considerable media coverage." uch re-analysis studies should help support better evidence-based policy, but the World Health Organization was quick to declare its continued commitment to deworming the world swiftly after the Cochrane review came out." WHO has also recently updated its guidance about deworming programs in its Library of Evidence for Nutrition Actions (eLENA).
ISHN briefly examined the 2015 Cochrane Review with a view to determining if the RCT studies and hence the review used common sense, context and different combinations of interventions as part of its analysis. We did this because we often find that RCT's and Systematic Reviews often are lacking in such considerations because of the narrow focus imposed on them by virtue of the protocols and procedures for such studies and reviews.Here are a couple of comments that should be considered as his debate move forward:
This is an important illustration of how the required narrow focus of RCT's and systematic reviews can ignite debates that are not really based on the real world. Given the increased attention being given to Neglected Tropical Diseases by WHO, we need to ensure that such scientific advice based on research evidence is tempered by ongoing analysis of databases such as student enrollment patterns over several years as well as the professional advice gathered in structured consultations with program staff,
(This item is among the 5-10 highlights posted for ISHN members each week from the ISHN Member information service. Click on the web link to join this service and to support ISHN)
ISHN briefly examined the 2015 Cochrane Review with a view to determining if the RCT studies and hence the review used common sense, context and different combinations of interventions as part of its analysis. We did this because we often find that RCT's and Systematic Reviews often are lacking in such considerations because of the narrow focus imposed on them by virtue of the protocols and procedures for such studies and reviews.Here are a couple of comments that should be considered as his debate move forward:
- The Cochrane Review considers the impact of a single dose of pills, multiple doses of pills as they are applied to all students in an endemic area or just to the students who are infected.
- The review reports that a single pill administered in all regions does not have an impact on average weight, cognition, school participation or academic achievement. However, the review does not seem to differentiate among populations that have high, medium or low infection rates. From a common sense point of view, it would seem obvious that an intervention affecting only a small percentage of students over a short period of time (most studies were less than a few years) would not have much effect on the average weight or performance of the entire group.
- The review, and likely the RCT's examined in the review, does not differentiate or examine the context of this single intervention in depth in the review. Is the pill administered as part of an overall effort to make the school healthier through a school health approach, or is this just the administration of a medication? Is there a mandatory health education curriculum or program in place to complement the administration of the medicine? Are parents involved? By asking these types of questions, we can reveal that the problem of inadequate descriptions of contexts and control groups in RCT studies is likely at play here.
- Similarly, the review does not examine if the intervention of giving pills is coordinated with additional nutrition support (to catch up children weakened by the disease) or changes are made in classrooms to catch there students up academically as well.
This is an important illustration of how the required narrow focus of RCT's and systematic reviews can ignite debates that are not really based on the real world. Given the increased attention being given to Neglected Tropical Diseases by WHO, we need to ensure that such scientific advice based on research evidence is tempered by ongoing analysis of databases such as student enrollment patterns over several years as well as the professional advice gathered in structured consultations with program staff,
(This item is among the 5-10 highlights posted for ISHN members each week from the ISHN Member information service. Click on the web link to join this service and to support ISHN)
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