Cost-Related Medication Nonadherence in a Nationally Representative US Population with Self-Reported Glaucoma

To determine the rates of cost-related nonadherence to medications among US adults with glaucoma and to determine if participants with glaucoma have more cost-related medication nonadherence than those without glaucoma.

Cross-sectional study.

Participants in the 2016-2017 National Health Interview Survey (NHIS), a cross-sectional survey regarding health topics that is administered annually to a nationally representative sample of noninstitutionalized adults in the United States.

We calculated proportions of NHIS participants with and without self-reported glaucoma who reported cost-related nonadherence over the previous 12 months. We analyzed responses to 7 survey items that dealt with medication cost-related issues to any/all of a participants' medication: couldn't afford a prescribed medication; skipped medication doses to save money; took less medicine to save money; delayed filling a prescription to save money; asked doctor for lower cost medication to save money; bought prescription drugs from another country to save money; used alternative therapies to save money. We performed univariable and multivariable logistic regression to evaluate the association between self-reported glaucoma diagnosis and responses to these selected questions.

Proportion of participants with and without self-reported glaucoma who reported cost-related nonadherence.

Participants with glaucoma reported they could not afford prescribed medication more frequently than participants without glaucoma (8.2% vs. 6.4% P = 0.024). Adjusted predicted proportions from a multivariable model demonstrated that participants with glaucoma responded that they had greater cost-related barriers to medication access.

In this nationally representative sample of the US population, after adjustment for confounding variables, participants with glaucoma more frequently reported cost-related nonadherence to medications compared with participants without glaucoma. Providers prescribing medication to patients with glaucoma should be aware of these findings and consider the impact of medication cost on their patients' ability to adhere to therapy.