Invited discussant of the study on medication nonadherence, Michaela A. Dinan, PhD, Co-Leader of Cancer Prevention and Control at Yale Cancer Center and Associate Professor of Chronic Disease Epidemiology at the Yale School of Public Health, in Connecticut, noted that the CAHPS survey data provide a “unique opportunity to obtain patient-reported outcomes and opinions regarding their health care.” However, these surveys are not administered at times directly related to cancer diagnosis.
“Because patients were a median of 7 years out from their diagnosis, the actual prescriptions for which adherence was being assessed may not have all been medications directly related to their cancer care,” said Dr. Dinan. “It’s also unclear whether patients were nonadherent to multiple medications or just the more expensive ones, since only a single metric of finance-related nonadherence was provided in the survey.”
Michaela A. Dinan, PhD
Interpreting Survey Findings
The study also observed that differences in out-of-pocket costs in patients who did vs did not report financially motivated nonadherence were larger in urban-dwelling patients than in patients living in rural areas. The investigators concluded that cost-related prescription adherence was associated with total out-of-pocket costs, with less focus on out-of-pocket co-pays for the drugs themselves.
“In survivors reporting nonadherence, out-of-pocket drug costs were only about $76 more than patients who were adherent,” said Dr. Dinan, who noted that most of the difference in costs was related to outpatient and physician services. “One interpretation is that the overall financial medical burden is relevant to adherence more than just the direct co-pays for drugs.”
Dr. Dinan also highlighted the decreased difference in out-of-pocket costs for patients in rural areas. Although she agreed with the authors that prescription-adherence decisions may be more cost-sensitive for rural patients, an alternative interpretation is that cost considerations may be less critical to rural patients (or more critical to urban patients).
“If the investigators had found a $0 difference between adherent and nonadherent patients in rural settings, for example, the interpretation would have been that money does not impact adherence,” said Dr. Dinan. “A smaller dollar amount difference between adherent and nonadherent patients does not necessarily suggest that out-of-pocket costs are stronger drivers of nonadherence for rural patients.”
Next Steps
According to Dr. Dinan, multivariable and subgroup analyses in the future might help to disentangle these factors. Because adherence was survey-based, an investigation using Medicare Part D data to compare patient self-reported adherence and objective prescription-fill data could also be useful to validate these data, she added.
Finally, said Dr. Dinan, it would be interesting to explore how financial factors such as lost wages, incomes, savings, and social support impact financial burdens to adherence.
DISCLOSURE: Dr. Dinan has received research funding from AstraZeneca and Janssen.
