Validation of the Sinhala Berlin and STOP-Bang questionnaires to detect obstructive sleep apnoea risk among antenatal women in Sri Lanka

Introduction: Screening can facilitate early detection and management of obstructive sleep apnoea (OSA) during pregnancy and improve pregnancy outcomes. Our aim was to determine the validity of the Sinhala translation of the Berlin and STOP-Bang questionnaires to detect the OSA risk among Sri Lankan antenatal women.

Methods: Berlin and the STOP-Bang questionnaires were translated to Sinhala language using the standard translation/ back-translation method. Face, content, and consensual validity of the Sinhala versions of Berlin (Berlin-S) and STOP-Bang (STOPBang-S) questionnaires were determined through a modified Delphi process conducted among respiratory physicians. These validated versions were administered to 200 antenatal women at selected antenatal clinics. The exploratory and confirmatory factor analyses (EFA and CFA) were performed. Internal consistency was assessed. Test-retest reliability and Inter-interviewer reliability for these questionnaires were assessed using Cohen’s kappa (k) and intra class correlation coefficient (ICC) values, respectively.

Results: Berlin-S and STOP-Bang-S showed good content, consensual and face validity. The EFA for Berlin-S confirmed a three-factor model compatible with the original instrument but CFA confirmed a one-factor model. The EFA for STOP-Bang-S confirmed a two-factor model. The CFA confirmed a one-factor model that was compatible with the original factor structure. The internal consistency of Berlin-S and STOP-Bang-S were satisfactory. Testretest reliability of Berlin-S and STOP-Bang-S were high for Berlin-S categories (k 0.828 [95% CI: 0.65-1.00]) and STOP-Bang-S score (ICC 0.982 [95% CI: 0.954-0.993]) respectively. The Cohen’s kappa value for the Inter-interviewer reliability of Berlin-S categories was 1.00 (95% CI: 1.00-1.00) and the ICC of STOP-Bang-S total score were 0.992 (95% CI: 0.960-0.994).

Conclusions: The Sinhala versions of Berlin and STOP-Bang questionnaires are valid and reliable tools to screen for OSA risk among antenatal women in Sri Lanka.