By Paul Saunderson, Chair of the ILEP ITC
24th August 2018
This month, the full WHO Guidelines for the Diagnosis, Treatment and Prevention of Leprosy, and the Report of the literature review were released, although the Executive Summary, giving the main recommendations has been in the public domain for some time and has been discussed quite widely.
The full documents are available at http://www.searo.who.int/entity/global_leprosy_programme/en/
Over the last 15 years or so, WHO has established a rigorous process for reviewing evidence and writing official Guidelines on medical matters. This is the first time this has ever been done for leprosy, and it is stated on page 25 that they will be valid until 2022, unless new evidence becomes available. Part 1 (page 1) of the Guidelines describes the process in detail. Medical care generally has improved incrementally in recent decades, especially in the Western world, because of the wide acceptance of evidence-based medicine and the robust methods with which the evidence is assessed.
It may be noted that the quality of the evidence on which these recommendations for leprosy are based is low, except for the evidence underlying chemoprophylaxis with single dose rifampicin, which is described as moderate, the COLEP study being one of very few randomized controlled trials ever done in leprosy. Sadly, due to poor study design, small sample sizes and the lack of good follow-up – mainly the results of under-funding – most research in leprosy is regarded as of low quality.
All the recommendations are termed ‘Conditional’ and this is explained towards the end of Part 1 (on page 13): “A conditional recommendation is one for which GDG concluded that the desirable effects of adhering to the recommendation probably outweigh the undesirable effects, but the balance of benefits to harms was relatively small or there was less certainty about the conclusions. The implications of a conditional recommendation are that, although most programmes or settings would adopt the recommendation, some would not or would do so only under certain conditions.”
The Guidelines are written for National Leprosy Control Programs and it is expected that many programs will adopt the recommendations as being the best available options in the areas of diagnosis, treatment and prevention of leprosy, given the evidence we have at present. The Guidelines are clear about the necessary conditions required before implementing the recommendations; for example, the need for programs to adequately identify and manage contacts of leprosy cases before introducing chemoprophylaxis (page xiv). For most ILEP members, support of National Programs with whom they work, and the strategies they adopt, will be the norm.
The fact that so much of the evidence is of poor quality, sends a salutary message to those of us engaged in, or supporting, research. Part 3 (page 27) of the Guidelines presents research priorities. The most appropriate response for ILEP members to make would be to redouble our efforts in research, so that when the time comes to update these Guidelines, there will be evidence of a much higher quality on the basis of which more robust recommendations can be made. Similarly, the Leprosy Research Initiative, supported by many ILEP members, must ensure that the studies it supports are well designed and will produce evidence which will be rated more highly. It is good to note that a number of larger studies of chemoprophylaxis are already funded, so more evidence will appear in due course.