Translation and Validation of a Swahili Version of the Sinonasal Outcome Test (Snot-22)

Abstract

Background: Chronic rhinosinusitis (CRS) affects millions worldwide. Sinonasal Outcome Test (SNOT-22) is the most suitable outcome measure in evaluating CRS patients. It was developed in English. Administering it in English would exclude our population who communicate in Swahili. It is therefore important to develop a Swahili questionnaire. Objective: To translate and validate a Swahili version of the Sinonasal Outcome Test (SNOT) -22 questionnaire. Study Design: This was a prospective cohort study. Study setting: The study was conducted in the Ear, Nose and Throat (ENT) department of Kenyatta National Hospital. Study duration: This study was carried out from July 2019 to February 2020. Study population: There were two cohorts of adult patients with CRS. One of 69 patients on scheduled clinic and another of 35 patients scheduled for sinonasal surgery. Methodology: The SNOT-22 was translated into Swahili using World Health Organisation (WHO) method, followed by testing on day 1 and retesting on day 14 to 69 cases to determine its consistency and validity. The validated SNOT-22 was administered to 35 patients undergoing endoscopic sinus surgery (ESS) before surgery, then three months post-surgery to determine its reliability and magnitude of treatment effect. Results: In the test retest arm, females constituted 45(62.5%), and males 24(34.8%). In the operative arm, females made up 60% (21). Mean age in test retest group was 37yrs±13.61 and 33.4±8.26 in operative arm. Cronbach’s alpha was 0.799. Intraclass correlation coefficient was 0.799(CI: 0.72-0.86, P<0.001). Comparing scores in preoperative and postoperative groups showed

statistical significance, 55.65±26.92 vs 19.41±10.35, P<0.001.Magnitude of treatment effect Cohen’s d value was 1.77. Conclusion and recommendations: The Swahili version of the SNOT 22 from this study has good internal consistency, reliability and validity. It is a valid instrument in assessing HRQoL in Swahili speaking patients. It can be used for patient care and clinical research.