Medication adherence varies widely depending on the condition for which a patient is taking that medication, according to a retrospective study of more than 15,000 patients in an integrated health system.
Researchers investigated medication adherence among patients with multiple sclerosis, cancer, hyper cholesterolemia, hypertension, osteoporosis, depression, diabetes, and asthma/chronic obstructive pulmonary disease (COPD). Patients were required to have only 1 disease for which they were taking a single medication. By examining pharmacy claims records, the researchers identified patients with a minimum of 2 prescription fills for ≥28 days of medication supply within 1 year. Adherence was calculated using the medication possession ratio, which had to be ≥80% for the patient to be determined adherent.
There was wide variation in adherence by condition, ranging from 85% for multiple sclerosis to 32% for asthma/COPD. Efforts to improve adherence in conditions with the lowest compliance levels are needed, and, as such, the authors are now conducting followup research among patients with diabetes and asthma/ COPD to better understand facilitators and barriers to optimal medication use.