Tuesday, April 10, 2012

Disability indices


Leprosy Mailing List – March 6th, 2012 
Ref.:    Disability indices
From:  C Smith, Aberdeen, Scotland, UK

Dear Emanuel,
Thank you for giving details of the Bechelli Index used in FIOCRUZ [LML Feb. 25th, 2012].  I know it well but I had called it the Disability Index.  I used it extensively in the 1970s and 1980s in my doctoral thesis using the Disability Index 2 as the outcome in leprosy control – see the attached papers.
There were 3 indices proposed in the 1971 paper by Bechelli and Dominguez.  I wondered when the grading changed from a scale of 0,1,2, and 3 to a scale of 0,1 and 2.  The answer is in the WHO Expert Committee on Leprosy Report 768 published in 1988 and the change is described in the WHO Guide to Leprosy Control, 2nd Edition in 1988.  The reason given for the change was that the grading system was considered to be ‘rather beyond the comprehension of primary health workers’.  1988 was the period when the uptake of MDT to replace dapsone mono-therapy was being advocated, and primary care was becoming involved in the delivery of leprosy services. 
The index you are using is the new 0,1 and 2 scale recommended by the Expert Committee in 1988 to calculate the Disability Index 2 (Bechelli Index 2) by adding all the scores for each eye, hand and foot and dividing by 6 to give an average.  The EHF score is actually the Bechelli Index 1 where the maximum score for each eye, hand and foot is added to produce the total score rather than the average score.         
The questions raised by Linda Lehman [LML March 1st, 2012] are very relevant about which index to use and when?  The Bechelli Index 2 which you use and the EHF score (Bechelli Index 1) are useful in monitoring progress in individual patients whereas the Grade 2 maximum score is more limited to monitoring early case detection in programmes with less expertise.
The important point is that we need to be clear which assessment we are using for which purpose, and that we all use them in the same way to be consistent and to provide comparable information.
Many thanks,
Cairns

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