Objectives: A cancer diagnosis can influence medication adherence for chronic conditions by shifting care priorities or reinforcing disease prevention. This study describes changes in adherence to medications for treating three common chronic conditions – diabetes, hyperlipidemia, and hypertension – among older adults newly diagnosed with non-metastatic breast, colorectal, lung, or prostate cancer. Methods: We identified Medicare beneficiaries aged ≥66 years newly diagnosed with cancer and using medication for at least one chronic condition, and similar cohorts of matched individuals without cancer. To assess medication adherence, proportion of days covered (PDC) was measured in six-month windows starting six-months before through 24 months following cancer diagnosis or matched index date. Generalized estimating equations were used to estimate difference-in-differences (DID) comparing changes in PDCs across cohorts using the pre-diagnosis window as the referent. Analyses were run separately for each cancer type-chronic condition combination. Results: Across cancer types and non-cancer cohorts, adherence was highest for anti-hypertensives (90–92%) and lowest for statins (77–79%). In older adults with colorectal and lung cancer, adherence to anti-diabetics and statins declined post-diagnosis compared with the matched non-cancer cohorts, with estimates ranging from a DID of −2 to −4%. In older adults with breast and prostate cancer cohorts, changes in adherence for all medications were similar to non-cancer cohorts. Conclusion: Our findings highlight variation in medication adherence by cancer type and chronic condition. As many older adults with early stage cancer eventually die from non-cancer causes, it is imperative that cancer survivorship interventions emphasize medication adherence for other chronic conditions.
Bibliographical noteFunding Information:
This research was support by the National Institute on Aging ( NIA R01 AG050733 ; PI: Trogdon). The database infrastructure used for this project was supported through the University of North Carolina Clinical and Translational Science Award ( UL1TR001111 ) and the UNC Lineberger Comprehensive Cancer Center , University Cancer Research Fund via the State of North Carolina.
Dr. Lund's spouse is a full-time, paid employee of GlaxoSmithKline who also holds stock in the amount of approximately $42,000. Dr. Lund also receives unrelated grant funding paid to her institution from AbbVie. Dr. Wheeler receives unrelated grant funding paid to her institution from Pfizer. All other co-authors have no potential conflicts of interest to report.
The database infrastructure used for this project was supported through the University of North Carolina Clinical and Translational Science Award (UL1TR001111) and the UNC Lineberger Comprehensive Cancer Center, University Cancer Research Fund via the State of North Carolina.
This study used the linked SEER-Medicare database. The interpretation and reporting of these data are the sole responsibility of the authors. The collection of cancer incidence data used in this study was supported by the California Department of Public Health as part of the statewide cancer reporting program mandated by California Health and Safety Code Section 103885; the National Cancer Institute‘s Surveillance, Epidemiology and End Results Program under contract HHSN261201000140C awarded to the Cancer Prevention Institute of California, contract HHSN261201000035C awarded to the University of Southern California, and contract HHSN261201000034C awarded to the Public Health Institute; and the Centers for Disease Control and Prevention‘s National Program of Cancer Registries, under agreement # U58DP003862-01 awarded to the California Department of Public Health. The ideas and opinions expressed herein are those of the author(s) and endorsement by the State of California Department of Public Health, the National Cancer Institute, and the Centers for Disease Control and Prevention or their Contractors and Subcontractors is not intended nor should be inferred. The authors acknowledge the efforts of the National Cancer Institute; the Office of Research, Development and Information, CMS; Information Management Services (IMS), Inc.; and the Surveillance, Epidemiology, and End Results (SEER) Program tumor registries in the creation of the SEER-Medicare database.
- Chronic conditions
- Medication adherence
PubMed: MeSH publication types
- Journal Article