PATTERNS AND PREDICTORS OF DEPRESSION TREATMENT AMONG OLDER ADULTS WITH PARKINSON’S DISEASE AND DEPRESSION IN AMBULATORY CARE SETTINGS IN THE UNITED STATES

OBJECTIVES: The objectives of this study were to assess the patterns and predictors of depression treatment among older adults with Parkinson's disease (PD) and depression seeking care in ambulatory settings in the United States (US). METHODS: We adopted a cross-sectional study design by pooling multiple-year data (2005-2011) from the National Ambulatory Medical Care Survey (NAMCS) and the outpatient department of the National Hospital Ambulatory Medical Care Survey (NHAMCS). The final study sample consisted of visits by older adults (age ≥ 65 years) with PD and depression. PD was identified by using ICD-9-CM code of 332.xx. Depression diagnosis was identified if answer to the question "Regardless of the diagnoses written...does the patient now have: depression?" was "yes". Depression treatment, which was the dependent variable for this study, was defined as antidepressant use with or without psychotherapy. To identify the predictors of depression treatment, multivariate logistic regression analysis was conducted adjusting for predisposing, enabling, and need factors. Complex survey design of NAMCS-NHAMCS were adjusted in all analyses to obtain nationally representative estimates. RESULTS: According to NAMCS-NHAMCS 2005-2011, approximately 1.7 million visits recorded a concurrent PD and depression diagnosis. Depression treatment was recorded in 57.63% of the study sample visits, mainly driven by antidepressant use alone. Men were 64% less likely (Odds Ratio=0.359,95% CI 0.139-0.932) than women to receive depression treatment. Individuals with PD and depression were 74% more likely (Odds ratio=1.743, 95% CI 1.376-2.209) and 44% less likely (Odds ratio=0.559, 95% CI 0.396-0.790) to receive depression treatment with the increase in each number of medication used and chronic condition respectively. CONCLUSIONS: Approximately six out of ten older adults with PD and depression received some form of depression treatment. Future real-world long-term studies should investigate health outcomes associated with depression treatment in this population.