Objective: This study evaluated the association between various socioeconomic and clinical factors relating to patients and physicians and the prescribing of medications that have a high abuse potential or are expensive for the treatment of sleep difficulties in a nationally representative sample of outpatient physician visits in the United States.
Methods: This cross-sectional study used data from the National Ambulatory Medical Care Survey from 1996-2001. Patients aged > or =18 years who received treatment for sleep difficulties in US outpatient settings over this period were included in the study sample. Office visits were considered related to insomnia/sleep difficulties if relevant International Classification of Diseases, Ninth Revision, diagnosis codes were recorded and if insomnia was reported as the reason for the visit or any medication with a primary indication for insomnia was prescribed. Medications associated with dependence and withdrawal symptoms were categorized as having a high abuse potential. Medications were considered expensive if the average wholesale price of 100 tablets was > or =$150 (ie, the 75th percentile of the total cost of all medications prescribed for sleep disorders only). The data were subjected to multivariate logistic regression analysis.
Results: From 1996 through 2001, 2966 unweighted patient visits for insomnia/sleep difficulty were identified, representing approximately 94.6 million weighted observations in the overall US population; pharmacotherapy only was prescribed at 48% (45 million) of these visits. Medications with abuse potential were prescribed at 53% (24 million) of visits. Among visits at which pharmacotherapy was prescribed, visits by male patients were 39% less likely than visits by female patients to result in a prescription for a medication with abuse potential (odds ratio [OR] = 0.61; 95% CI, 0.45-0.81). Visits by patients with psychiatric comorbidities were 80% more likely to be associated with receipt of a prescription for a medication with abuse potential than were visits by patients with no such comorbidities (OR = 1.80; 95% CI, 1.31-2.47). Expensive medications were prescribed at 25% (15 million) of visits involving some pharmacotherapy. Patients aged > or =65 years were 44% less likely to receive a prescription for an expensive medication than was the reference group, patients aged 18 to 34 years (OR = 0.56; 95% CI, 0.35-0.90). Hispanic patients were 56% less likely to receive a prescription for an expensive medication than were non-Hispanic patients (OR = 0.44; 95% CI, 0.22-0.88).
Conclusions: This study found an increased probability of female patients with sleep difficulties receiving a medication with high abuse potential in outpatient settings in the United States from 1996 through 2001. In addition, there was a possible association between the age and ethnicity of patients with insomnia/sleep difficulties and the prescribing of expensive medications for sleep difficulties.