To construct a questionnaire for estimation of sleep related breathing disorders in Indians.
To assess the inter-observer reliability, a specialist and a trained health worker administered the questionnaire to 135 adult individuals, who presented in the outpatient department of V.P. Chest Institute. Taking the specialist's opinion as the reference, various parameters of reliability were calculated. The test-retest reliability was calculated by questioning 50 individuals twice after an interval of one week by the same observer. The questionnaire was validated by performing polysomnography on 11 normal and 11 individuals with sleep related symptoms suggestive of obstructive sleep apnoea (based on the questionnaire).
The sensitivity, specificity and predictive values were calculated for each question. While sensitivity ranged from 42–55% (questions on snoring and daytime sleepiness with a sensitivity of 87% and 93% respectively), specificity was found to be 94 – 96% with an efficiency of 0.899. The kappa value for intra-observer reliability was found to be 0.815. With polysomnography as the gold standard for diagnosing sleeprelated breathing disorders, the questionnaire had a sensitivity of and specificity of 82%.
Our questionnaire compares favourably with other standard questionnaires like the Berlin Questionnaire.
This short questionnaire with good reliability is suitable for Indian population studies.
sleep related breathing disorders, reliability, validity, polysomnography
