Sedating medications and undiagnosed obstructive sleep apnea: physician determinants and patient consequences.

BACKGROUND: Sedative medications may be inadvertently prescribed to patients with undiagnosed obstructive sleep apnea (OSA) and may worsen daytime sleepiness. STUDY OBJECTIVES: To determine whether patients with undiagnosed OSA were prescribed sedative medications and whether such prescriptions increased the risk for traffic accidents. A secondary objective was to determine physician characteristics associated with such prescription practices. DESIGN: Retrospective chart review. Telephone interviews of patients and physicians. INTERVENTION: None. PATIENTS: One hundred fifty-one consecutive patients at a sleep laboratory. RESULTS: Forty-one of 137 (30%) patients with undiagnosed OSA had received prescriptions for sedating medications. Regression analysis identified self-report of sleepiness while driving (p = .05) and prescription for risperidone as independent risk factors for motor vehicle accidents (p = .005), while prescription of any sedative (excluding risperidone) tended to be associated with accidents (p =.10). In patients with severe OSA, prescription of sedating medications was associated with a greater risk for motor vehicle accidents than those without such prescriptions (relative risk = 2.6; p = .04). In patients with prescription for sedating medications (n = 41), the apnea-hypopnea index was directly proportional to the risk for motor vehicle accidents (r2 = 0.26; p = .001) suggesting a 'dose effect' of severity of sleep-disordered breathing on risk for accidents. Physicians who did not usually treat patients with sleep disorders were more likely to prescribe sedatives to patients with undiagnosed OSA than were physicians with such expertise: neurologist, pulmonologist, or psychiatrist (52% vs 10%; relative risk = 5.2; p = .02) CONCLUSION: Prescription of sedating medications may increase the risk of road accidents in patients with undiagnosed severe OSA, and such prescription practices are less likely to occur in physicians with expertise in sleep medicine.