OBJECTIVE : This research was performed to analyze selected socioeconomic and clinical factors relating to both physicians and patients associated with physicians' prescribing of expensive medications and medications with abuse potential side effects for treatment of sleep difficulties in a nationally representative sample of outpatient physician visits in the United States. METHODS: A multivariate logistic regression method was used to analyze the 1996-2001 National Ambulatory Medical Care Survey data to determine the patient and physician factors associated with a prescription for expensive medication and medications with abuse potential side effects in outpatient settings. RESULTS: From 1996 to 2001, about 94.6 million sleep-difficulty related visits were made to outpatient physician offices in the United States. Forty eight percent (45 million) of sleep-difficulty related visits received prescription for medication therapy only. Patients over 65 years of age were 44% less likely (OR: 0.56, 95% CI: 0.35-0.90) to receive an expensive medication prescriptions than patients aged 18-34 years (reference group). Hispanic patients were 56% less likely to receive an expensive medication prescription than Non-Hispanic patients during their visits (OR: 0.44, 95% CI: 0.22-0.88). Male patient visits were 39% less likely than female patient visits to result in receipt of medication with abuse potential among patient visits receiving medication therapy (OR: 0.61, 95% CI: 0.45-0.81). In addition, patients with mental comorbidities were 80% more likely to be associated with receipt of a prescription of medications with abuse potential than patients with no mental comorbidities (OR: 1.80, 95% CI: 1.31-2.47). CONCLUSIONS: This study indicated that patient's age and ethnicity influence physician prescribing of expensive medications for treatment of sleep difficulties. In addition, increased probability of receipt of medication with abuse potentials in female gender is of concern, when safer alternative medications with lower abuse potentials are easily available.