Contribution of cost to treatment nonadherence in the US breast cancer survivors: a population-based analysis

Breast cancer survivors are often prescribed medications for at least 5 years to reduce recurrence risk, yet some forego this treatment due to cost. We sought to elucidate the prevalence of this and the factors contributing to it.

The National Health Interview Survey (NHIS) is a population-based survey, representative of the civilian non-institutionalized US population, administered annually by the CDC. People diagnosed with breast cancer within the past 5 years surveyed in the 2018 NHIS formed the cohort of interest.

Of the 24,858 breast cancer survivors surveyed, representing 244,607,304 in the population, 6.32% stated that they needed a prescription medicine within the past 12 months, but didn't get it filled because they couldn't afford it. Of those who had gotten a prescription within the past 12 months, 5.71, 5.94 and 7.48% had either skipped doses, taken less medication than prescribed, or delayed filling a prescription, respectively, to save money. 11.99% of people had done at least one of these, thereby foregoing treatment. On bivariate analyses, factors associated with foregoing treatment included age, race, education, family income, and insurance status (p < 0.001 for all). On multivariable analysis, age, race, family income, and insurance status were all independent predictors of foregoing treatment (p < 0.001 for all); education status was not significant in the model (p = 0.211).

Roughly 12% of breast cancer survivors who are prescribed medications within the first 5 years of their diagnosis will forego treatment due to cost. Family income and insurance status are key modifiable drivers of this.