Monitoring impairment in leprosy: choosing the appropriate tool

[[[ Objective: ]]] To assess to what extent the Maximum WHO Impairment Grade, the EHF Score and Impairment Summary Form (ISF) reflect changes in impairment, both in number(s) and severity. [[[ Design: ]]] The impairment data at registration and at release from treatment of 444 persons affected by leprosy registered for MDT from 1994-2003 in Federal Capital Territory, Nigeria were analysed using three monitoring tools. [[[ Results: ]]] Of the 444 patients, 92 people had a change (10 deteriorated, 70 improved while 12 had improvement in some parts of their body and deterioration in other parts) in their impairment between Registration and Release from Treatment. Of the 10 people whose impairment status deteriorated, the WHO Grade missed 7 and the EHF score missed 4. The ISF missed none. Of the 70 whose impairment status improved, the WHO grade missed 27; the EHF score missed 20 and the ISF missed 9. The WHO Grade had a sensitivity of 50%, the EHF Score 61% and the ISF 90%. Negative predictive values were 88%, 91% and 98% respectively. [[[ Conclusions: ]]] The Maximum WHO Impairment Grade use should be limited to an indicator of late case detection. The EHF score is better used at programme level than individual patient level. The ISF is a sensitive tool for monitoring impairments at patient level to aid clinical decision making.