Epidemiology of Sleep Disorders in the Adult Population of Delhi: A Questionnaire Based Study

Abstract

A questionnaire based survey was conducted to determine the prevalence of common sleeprelated disorders in the adult population of Delhi. The questionnaire used for the purposes of this study was adapted from those by Chervin and the Stanford Sleep Clinic questionnaire. A total of 4000 questionnaires were distributed of which 2774 were received back. And finally 2475 questionnaires were selected for analysis as they satisfied all criteria for acceptance. A subgroup of 200 (a number that was considered to be statistically significant) adults were randomly selected from the total pool of adults that reported snoring and were then subjected to whole night in-lab supervised polysomnography. The overall prevalence of snoring was found to be 39.5% (Males = 49.5%, Females = 29%). The overall prevalence of Sleep disordered breathing (SDB) was 4.3%. Approximately 48.6% of the adult population was seen to suffer from excessive daytime sleepiness. The prevalence of symptoms suggestive of restless leg syndrome was 8.2% and was found to correlate significantly with BMI, rising age and female gender. The overall prevalence of sleepwalking in the adult population studied was 6%. The prevalence of nightmares in the adult population studied was 30.6% while bruxism was observed to be present in 9.2% of the adult population studied. Approximately 2.3% of the entire study population admitted that they consumed sleeping pills. Its use correlated significantly with rising socio-economic strata and symptoms suggestive of disorders of initiation and maintenance of sleep (DIMS) . Approximately 10.7% of the study population responded affirmatively to have met with road traffic accident in the past few years and 28.1% of the adult population was observed to have complaints suggestive of disorders of initiation and maintenance of sleep. More than half the population under study was observed to be sleep-deprived (sleep time <8 hours per day); and 29.3% of them slept for less than seven hours. In this questionnaire-based survey, approximately 55% of the study population was observed to have some type of sleep-related disorder. This indicates that the impact of sleep disorders on the morbidity profile of this segment of urban society is of a gigantic proportion. It also reflects the phenomenal burden of undiagnosed sleep disorders in this segment of the general population as well as its impact on social, mental, physical and economic health of the society.