Anti-Depressant Adherence Among Hispanic Patients in an Integrated Health Care Treatment Model

Background/Purpose: We report on antidepressant adherence among Hispanics seeking mental health services in primary care settings as an ancillary outcome from a National Institutes of Health-funded study. Participants were randomized to one of two educational interventions, and the overall study tested the effect of a culturally-tailored educational intervention on patients’ engagement in depression treatment within an integrated health care model. Depression treatment entailed psychotherapy with a licensed clinical social worker, medication alone, or a combination of both, over a 1-year period. Adherence to anti-depressant medications was measured throughout the project and compared across various demographic characteristics. Age was a key dependent variable used in this study due to literature showing that age can be significantly correlated, associated, and can be a significant predictor of adherence. Since Hispanic individuals often experience stigma, cultural barriers, and hesitancy related to anti-depressant treatment, we sought to understand what factors may predict the likelihood of adherence in an integrated health care model.

Methods: Longitudinal data was collected over a two-year period at a primary care community clinic. The project had an original sample of 150 Hispanic participants of whom a vast majority were female (88.7%). However, for the purpose of this study we focused on the 66 participants who were prescribed anti-depressant medications. Adherence was measured with the Patient Adherence Questionnaire (PAQ), a validated 2-item questionnaire that asks patients about their medication use (missed medications or dosage changes) over the past week. The study collected data on symptoms of depression, PTSD, anxiety, anti-depressant stigma, depression knowledge, and adherence to anti-depressants. For this study, we looked at patient adherence at two key time points (1-month and 13-weeks). We utilized binary logistic regression to identify factors that may increase or decrease the likelihood of adherence in Hispanic patients at a community primary care clinic.

Results: T-test and chi-square analyses did not reveal significant differences between the original sample and those who initiated anti-depressant treatment. Non-adherence to anti-depressant medication was 49.3% at 1-month and 57% at 13-weeks post treatment initiation. Logistic regression analyses revealed that age was the only significant predictor of anti-depressant non-adherence at 1-month (OR = .872, p = .022) and 13-weeks (OR=.899, p = .003). In other words, as age increased, the likelihood of non-adherence decreased by 12.2% at 13-weeks post treatment initiation and by 11.1% at 1-month post treatment initiation.

Conclusions and Implications: In the current sample, the likelihood of Hispanic patients to remain adherent to antidepressant therapy increased with the age of the patient. Since primary care is the most likely place to be prescribed an antidepressant for Hispanic patients, further research to better understand adherence is essential. In addition, integrated health care interventions designed to help identify, reduce, or eliminate barriers to adherence and improve cultural understanding, may help address issues of non-adherence in primary care settings.