Determinants of nonmedical use, abuse or dependence on prescription drugs, and use of substance abuse treatment.

Background: Previous studies have found a negative association between health insurance and nonmedical use of prescription drugs (NMUPD), and abuse or dependence on prescription drugs (ADPD); and mixed associations between health insurance and use of substance abuse treatment (SAT). However, effect of health insurance in the specific subgroups of population is largely unknown.

Objective: To estimate the relationship between health insurance and (1) NMUPD, (2) ADPD, and (3) use of SAT services among 12-64 years old, noninstitutionalized individuals and to see if these relationships are different in different subgroups of population.

Methods: This study used cross-sectional survey data from 2007 National Survey on Drug Use and Health. Bivariate and multiple logistic regression analyses were conducted.

Results: In 2007, self-reported prevalence of NMUPD was approximately 10% (N=15,509,703). In multivariate analysis, NMUPD was negatively associated with health insurance, age, race other than non-Hispanic White, education, marital status, and income ($40,000-$74,999). Past year use of tobacco and alcohol were positively associated with NMUPD. Among those with private health insurance, Hispanics and individuals with family income less than $20,000 and $40,000-$74,999 were more likely prone to NMUPD than others. High school graduates with public health insurance were less likely prone to NMUPD. Approximately, 13% of nonmedical users reported ADPD (N=2,011,229). Health insurance and age were negatively associated with ADPD. However, people who were unmarried, reported fair/poor health, and used tobacco were more likely to report ADPD. Lastly, the use of substance abuse treatment programs was approximately 73% and 76% between NMUPD and ADPD population, respectively. Health insurance was not associated with use of substance abuse treatment. Individuals with high school education were 2.6 times more likely to use substance abuse treatment than the college graduates. Additionally, no significant interaction effects were found between health insurance, and sociodemographic factors on ADPD and the use of substance abuse treatment.

Conclusions: Health insurance had a differential impact on NMUPD only. Among privately insured, Hispanics and individuals reporting family income less than $20,000 were more likely to engage in NMUPD. There is a need to better understand and monitor the use of prescription drugs among these groups. This knowledge can help in developing public health programs and policies that discourage NMUPD among these individuals.