Abstract
BACKGROUND: The Sleep Quality Questionnaire (SQQ) is a short and easy-to-understand resourceful tool for measuring poor sleep quality; however, it remains to be validated. AIM: The focus of this study is to determine its reliability and validity among Nigerian adolescents. SETTING: Four gender-mixed schools within Benin City, Nigeria were selected to participate in the study. METHODS: Questionnaires containing the SQQ, the Sleep Condition Indicator (SCI), which is a validated scale, and the Hospital Anxiety and Depression Scale (HADS) from 377 students selected from the junior and senior secondary school students were analysed. RESULTS: The mean age calculated was 14.78 years for 174 male and 203 female students. Cronbach's alpha for the SQQ scale was 0.70. It correlated strongly with the SCI (rho = 0.93, p = 0.00), weakly with the HADS depression (rho = -0.19, p < 0.01) and anxiety (rho = -0.30, p < 0.01), but had no association with gender. Factor analysis revealed three factors with an eigenvalue greater than 1. Factors 1-3 accounted for 31.78%, 15.16% and 11.26% of the variance, respectively, totalling 58.2%. The reliability of each of the three factors was as follows: factor 1, 0.75; factor 2, 0.47; and factor 3, 0.62. The SQQ demonstrated good specificity and sensitivity at a cut-off point of 18. CONCLUSION: It is therefore recommended that the SQQ be included in the screening of sleep-related problems in adolescents, both in the primary and secondary care settings in Nigeria. CONTRIBUTION: The research shows that the Sleep Quality Questionnaire is both a reliable and valid screening tool among adolescents in Nigeria. Its brevity and simplicity further promote its use in clinical and non-clinical settings.