Introduction:Most information on the causes of blindness has come from examining children in special education. To obtain a more representative population based sample of children, we developed a novel method for ascertaining severe visually impaired (SVI) or blind (BL) children by training local volunteers to act as key informants (KI). The purpose of this study is to compare the demography and cause of blindness in children recruited by KI's with other ascertainment methods.
Method: Children with SVI/BL were recruited in all 64 districts of Bangladesh. Three sources for case ascertainment were utilized; schools for the blind (SpEdu), community based rehabilitation programs (CBR) and key informants (KIs). All data were recorded using the standard WHO/PBL Eye Examination Record.
Results: A total of 1,935 children were recruited. Approximately 800 KIs were trained. The majority of the children were recruited by the key informants (64.3%). Children recruited by KIs were more likely to be female (OR 1.6, p<0.001), of pre-school age (OR 14.1, p<0.001), from rural areas (OR 5.9, p=<0.001), be multiply impaired (OR 3.1, p=0.005), and suffering from treatable eye diseases (OR 1.3, p=0.005) when compared to SpEdu. Overall a child with an avoidable causes of SVI/BL had 40% (adjusted CI 1.1 to 1.7, p=0.015) and 30% (CI 1.0 to 1.7, p=0.033) higher odds of being ascertained using the KIs compared to SpEdu and CBR methods respectively.
Conclusion: Using this innovative approach has resulted in one of the largest studies of SVI/BL children to date. The findings indicate that KIs can recruit large numbers of children quickly, and that the children they recruit are more likely to be representative of all blind children in the community.
- Case ascertainment
- Childhood blindness
- Key informant
- schools for the blind