Translation, cultural adaptation and validation of the Thinking Healthy Programme manual for perinatal depression in Galle District, Sri Lanka

Abstract

Perinatal depression is a common, under-treated condition in Sri Lanka, where approximately one in five perinatal women experiences depressive symptoms and access to specialist mental health care is limited. The World Health Organization’s Thinking Healthy Programme (THP) is an evidence-based cognitive-behavioural intervention designed for delivery by non-specialist workers, but a locally validated Sinhala version for Public Health Midwife (PHM) delivery in Galle District was not available. We translated the THP manual from English into Sinhala using forward and back translation by four bilingual investigators, culturally adapted the draft using Bernal’s Ecological Validity Framework with a five-member multidisciplinary group and pre-tested the adapted version with five PHMs across five Medical Officer of Health areas in Galle District. We then validated the manual through a Modified Delphi process involving a nine-member multidisciplinary expert panel that assessed face, content and consensual validity over two iterative rounds and a final roundtable. The scale-level Content Validity Index was 0.96, with mean (SD) ratings of 3.8 (0.7) for relevance and 3.8 (0.1) for clarity. The panel reached unanimous consensus, supporting field-testing of THP delivery by PHMs.