Obstructive sleep apnea and excessive daytime sleepiness among commercial motor vehicle drivers in Lusaka, Zambia.

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) is a risk factor for a major public health problem, car crashes, due to excessive daytime sleepiness (EDS). Commercial vehicle driving (CVD) is a hazardous occupation, having a high fatality rate worldwide. There have been no studies on EDS and OSA in Zambia despite the high rate of annual road traffic accidents (RTAs). We aim to determine the prevalence of EDS and OSA risk among CVDs in Lusaka, Zambia to assess the impact of OSA on high RTA rates.

METHODS: This was a cross-sectional study. The STOP BANG Questionnaire and the Epworth Sleepiness Scale (ESS) were used. Consecutive sampling of drivers was done who were divided into low and high risk of OSA (HROSA). The risk factors associated with OSA in the bivariate analyses were subjected to a multivariate logistic regression model.

RESULTS: One hundred and thirty-six drivers participated in the study (all male) with a mean age of 48+/-5 years. The prevalence of HROSA was 22.8% out of whom 67.7% also had a EDS. Only 9.6% of the total cohort had EDS without HROSA. Using Fisher exact HROSA was significantly associated with older age (>50 years, p<0.001), obesity (BMI>30 p<0.001), Neck Circumference of > 40 cm (p=0.032) and hypertension (p<0.001). Snoring and EDS were significantly associated with RTAs (p<0.0001 and p 0.007 respectively).

CONCLUSIONS: High risk of OSA and EDS are common among CMV drivers in Zambia and underdiagnosed. The risk factors for OSA are amenable to preventive interventions.