Understanding the Causes of Nonadherence to Chronic Medications Among Patients With Cancer and Multimorbidity: A Qualitative Study

Background

When patients with multimorbidity (≥ 2 chronic diseases) are diagnosed with cancer, their adherence to non-cancer medications declines. Nonadherence in this patient population has been linked to an increased risk of disease progression, hospitalization, and death. However, the reasons for declines in adherence are not well understood.

Objective

To qualitatively explore barriers and facilitators of chronic medication adherence among patients with multimorbidity and active cancer.

Design

Semi-structured interviews conducted in March–November 2023.

Participants

Adults aged ≥ 50 years with 2+ chronic conditions and cancer diagnosed within the past year and under active treatment at one large academic health system. We used purposive sampling to include balanced numbers of advanced (stage 3–4) and non-advanced (stage 1–2) cancers, and perceived change in chronic medication adherence after cancer diagnosis (same/better vs. worse).

Approach

We asked participants to describe medication adherence barriers and facilitators, and experiences balancing cancer and non-cancer symptoms, medications, and medical appointments. We analyzed transcripts using applied thematic analysis.

Key Results

We interviewed 20 participants. The majority were female (14/20), had breast cancer (8/20) or lung cancer (6/20), and took 3+ medications (12/20). Half had stage 3–4 disease. Three themes emerged. First, participants felt forced to prioritize among their diseases, medications, and appointments. Many focused their energy on their cancer, putting management of their chronic diseases on pause. Second, participants’ trust in caregivers, medical teams, and their own self-confidence influenced their motivation to adhere to medications. Third, adherence was logistically difficult and depended on drug side effects, drug-disease interactions, drug-drug interactions, and conflicting recommendations from cancer and non-cancer care teams.

Conclusions

Patients with cancer and multimorbidity must manage the demands of their cancer and non-cancer treatments simultaneously and navigate relationships with multiple healthcare professionals whose recommendations may conflict. Interventions are needed to address barriers to adherence in this population.