Comparison of effectiveness of using trained key informants versus health surveillance assistants in identifying blind and visually impaired children in Malawi.

Abstract

Eye conditions associated with visual impairment and blindness in children, such as congenital cataract, can lead to long lasting visual problems if treatment is delayed. There is need to determine which method can be more effective in identifying blind and visual impaired children. In this study, two methods of identifying blind and visual impaired children (using key informants versus using health surveillance assistants) were compared in a randomised community study conducted in three districts in Southern Malawi. The ministry of Health was advocating for the training of Health Surveillance Assistants (HSAs) in primary eye care, which included case detection and refer of blind and visually impaired children; and the alternative was the training of key informants (KIs). The study was done to compare the effectiveness of the two methods of case identification and to provide guidelines on optimal approaches of identifying blind and severely visually impaired children in Malawi. Twelve clusters (group of villages) were selected, and six were randomly assigned to each group. After training in case identification and referral, Key informants and Heath surveillance assistant identified children from the clusters, within a six-week period, and the number of blind and visual impaired children identified in each group was determined and compared. In total, 159 Key informants and 151 Health Surveillance Assistants were selected and trained, and they identified 550 children with eye problems, among whom, after examination, only 15.1 % were blind or severely visually impaired. Key informants identified one and half times more blind/severally visual impaired children than HSAs (37 vs 22).The prevalence estimates of blindness among children identified by KIs was 3.3 per 10,000 (95% CI 2.7-3.9), while the prevalence estimates of blindness among children identified by HSAs was 1.9 per 10,000 (95% CI 1.3-2.5).The difference was statistically significant (P=0.03), but overall the number of children identified by both groups was lower than was the expected from prevalence estimates of 8.0 per 10,000. False positives between HSAs and KIs were comparable, with 68.8% of children identified by HSAs as blind, confirmed blind on examination, in comparison to 72.5% of children identified by KIs, also confirmed as blind on examination. Cortical blindness seconded by cataract were the commonest causes of blindness. In conclusion, Keys informants were more effective than Health Surveillance assistants in identifying blind and visually impaired children in Malawi, and this study supports and confirms findings from other areas