The impact of patient characteristics and social drivers of health factors on oral oncolytic adherence.

Abstract

Background: Oral oncolytic medication adherence is crucial for effective cancer treatment, yet adherence rates vary widely (16%-100%) depending on cancer subtypes, assessment methodologies, and patient contexts. The increased use of oral medications for various cancer types, although often advantageous over traditional parenteral infusions, has transferred the responsibility of medication administration and management to patients. As such, Stanford Specialty Pharmacy uses a team of pharmacists and liaisons who proactively follow-up with patients before each refill to track adherence and make recommendations where required. Although this program is a step forward in bettering patient outcomes, it does not address the root cause of medication nonadherence. It is vital to better understand trends associated with oral oncolytic medication adherence to better support patients with adherence.

Objective: To conduct a retrospective analysis of patient records at Stanford Health Care (SHC) Specialty Pharmacy to probe correlations between patient characteristics, social determinants and drivers of health, and adherence to oral oncolytic medications to better support patients with their medication adherence.

Methods: This population included patients aged at least 18 years who had an oral oncolytic dispensed from SHC Specialty Pharmacy between May 2022 and April 2023, with patient characteristics and adherence data taken from patients' electronic health records. Medication nonadherence was defined as a proportion of days covered less than 80%. Using multivariable mixed-effects logistic regression, the rate of nonadherence was compared across several patient characteristics, including age, race and ethnicity, and geographic residence.

Results: Among 939 patients, 73.75% demonstrated medication adherence, highlighting a high adherence rate within the SHC Specialty Pharmacy cohort. Smoking was significantly associated with 395% higher odds of nonadherence (95% CI = 1.07 - 14.6; P = 0.04) compared with smoking abstinence, whereas patients with obesity presented 59% lower odds of nonadherence compared with patients with normal weight (95% CI = 0.24-0.69; P < 0.001). Additionally, trends in primary language, race and ethnicity, and geographic residence in relation to medication adherence were seen.

Conclusions: These findings show multiple patient characteristics that are associated with oral oncolytic adherence. These identified patterns and additional studies will better inform targeted interventions for achieving equitable care and enhancing access to effective cancer treatments, leading to improved patient outcomes.