Explaining the continuing high prevalence of trichiasis unknown to the health system in intervention districts: a mixed methods explanatory study in four trachoma-endemic countries in Africa

• To explain the continuing high prevalence of trichiasis unknown to the health system in districts where it has been suggested that trachomatous trichiasis (TT) case finding, and outreach activities have covered the entire area

Specific objectives:

• To collect both survey and qualitative data in districts where it has been suggested that case finding, and outreach activities have covered the entire area
• To determine, the degree or magnitude of agreement (and disagreement) in “TT status” between standard population-based surveys and more detailed examination and interview
• To determine the proportion of TT cases correctly identified during the survey, correctly allocated to [a] ‘TT known to the health system’; [b] TT unknown to the health system’
• To determine the primary reasons trichiasis cases are inaccurately allocated to the above categories
• To determine the reasons that trichiasis cases truly unknown to the health system are failed to be identified and managed by the programme

At the 4^th Global Scientific Meeting on trachoma it was agreed that to assess whether the elimination prevalence target for trachomatous trichiasis (TT) has been reached, national programmes may use: (i) population-based prevalence surveys powered at evaluation-unit level; (ii) house-to-house case searches; or (iii) a combination of data from multiple adjacent evaluation units.

This multi-country mixed methods in Ethiopia, Kenya, Nigeria and Tanzania sets out to understand discrepancies between TT prevalence survey findings and programme or interview findings. The explanatory factors for these ‘mismatch’ situations may be on the patient side, the provider/programme side or a combination of them both.

In this study the research team will re-examine TT cases identified during recent Tropical Data prevalence surveys and subsequently consult the case finder and outreach registers to determine if the responses are a match or mismatch with the survey data. In the case of mismatch semi-structured interviews with case finders, surgeons, medical supervisors and programme staff will follow.

The results from this study will inform the need for any evidence-based programmatic changes, in relation to a) how case finding and outreach activities are conducted to ensure full geographical coverage; b) how recording and reporting of geographical coverage is done.