Identifying patients at high risk for obstructive sleep apnoea syndrome in Nigeria: A multicentre observational study

BACKGROUND Obstructive sleep apnoea is associated with significant health consequences. A significant proportion of hospitalized patients at risk for obstructive sleep apnoea were never identified and referred for polysomnography for diagnosis. The objective of this study was to determine the factors associated with high risk for obstructive sleep apnoea and use it to identify patients at risk for the condition in tertiary hospitals in Nigeria. METHODS This was a multicentre observational study of adult patients hospitalized in three selected hospitals from 15th January to 17th March 2015. Berlin questionnaire and Epworth sleepiness scale were used to assess for obstructive sleep apnoea risk and excessive daytime sleepiness respectively. Additional questions on traditional risk factors for obstructive sleep apnoea were also obtained. RESULTS Nine hundred and twenty-six patients were recruited into the study. Respondents' mean age was 44.3 years ± 15.2years, 486 (52.5%) were females and 556 (60.0%) had one or more medical co-morbidity and none of the patients had a previous diagnosis of obstructive sleep apnoea. Factors that were independently associated with high risk for obstructive sleep apnoea include systemic hypertension(aOR-10.33;95%: CI 6.42-16.61), obesity(aOR-7.87;95% CI: 4.33-14.29); excessive daytime sleepiness (aOR-3.77;95% CI :2.28-6.22), tobacco smoking (aOR-2.99;95% CI: 1.76-5.07), snoring in a first-degree relative (aOR-1.83;95% CI: 1.19-2.81); and the use of sedative (aOR-1.82;95% CI: 1.06-3.15). CONCLUSIONS This study shows that patients with systemic hypertension, obesity, excessive daytime sleepiness, history of smoking, snoring in a first-degree relative and use of sedatives are at high risk of obstructive sleep apnoea. None of the patients at high risk had a previous diagnosis of sleep apnoea by a physician, highlighting the diagnostic challenges of this condition. The results of this study will assist health care professionals in early identification of individuals at risk of obstructive sleep apnoea and subsequent referral for a sleep study.