Patient characteristics associated with medication adherence [abstract] Abstract uri icon

abstract

  • OBJECTIVE: To help understand medication adherence within HealthPartners, we developed a study to assess factors associated across eight different conditions. This presentation focuses on associated patient-related characteristics.
    METHODS: We identified all members 18+ with a minimum of two prescription fills for > 28 days’ supply within 1 year between January 2007 and March 2009. Medications of interest (n=128) were identified for the treatment of one of the following eight diseases: depression, hypertension, hypercholesterolemia, diabetes, asthma/COPD, multiple sclerosis, cancer or osteoporosis. Diagnosis records were identified by ICD-9 code and merged with the prescription order records. We then examined differences across conditions by age, sex, race, co-morbidity and geo-code. Data were examined first with patients who had only one of the eight conditions and had only one medication (n=15,334). Analyses were then repeated on the population of patients who had any number of conditions and any number of medications (n=31,636 patients). Adherence was calculated by the Medication Possession Ratio. We used an 80% threshold.
    RESULTS: Statistically significant differences were found. Males were generally more adherent than females, although the magnitude was small. Whites were more adherent than patients of other races and older patients were more adherent than those younger. Adherence was higher among patients living in areas having a higher proportion of residents with a high school education, lower poverty, and higher family income. Among patients with any number of conditions drug adherence increased with lower Charlson score, having fewer of the eight conditions we considered, and being on fewer drugs for those conditions. Substantial variation was found in drug adherence by condition, with multiple sclerosis, hypertension, hyperlipidemia, osteoporosis, and cancer having a high percentage of patients considered adherent (75% +). Whereas adherence rates for depression, diabetes, and asthma/COPD were 62%, 51% and 33% respectively.
    CONCLUSION AND IMPLICATIONS: We expected to find adherence to be higher as pharmacy is a covered benefit and access to medications available through multiple channels. Never-the-less, significant differences were found by sex, age, race, SES and across the multiple conditions studied. There remains great room for improvement specifically related to treatment for diabetes and asthma.

publication date

  • 2011