Impact of cancer diagnosis on persistence of oral antidiabetic drugs.

AIMS

The purpose of this study was to determine the effects of cancer occurrence on persistence of oral antidiabetic drugs (OAD) in France.

METHODS

A retrospective cohort including incident OAD users between 2006 and 2011 was set up using a permanent sample of health insurance beneficiaries (Echantillon Généraliste de Bénéficiaires, EGB). A Cox model was used to assess the association between cancer occurrence and OAD persistence. Non-persistence was defined as a gap in OAD treatment coverage between the end of a given prescription and a new one greater than or equal to 90 days. Cancer occurrence was studied as a time-dependent variable.

RESULTS

The study included 13,943 OAD users. Median follow-up was 760 days. After adjustment for age, sex, first OAD used, type of prescriber and polypharmacy, non-persistence risk was higher after a diagnosis of cancer: (HR: 1.93 and IC 95% 1.69; 2.21). Subgroup analyses according to cancer localization found a higher risk of non-persistence for lung cancer (HR: 2.66 and IC 95% 1.68; 4.23) and colorectal cancer (HR: 2.02 and IC 95% 1.40; 2.91).

CONCLUSIONS

Our findings indicate there is an association between cancer diagnosis and OAD non-persistence. Additional studies of this type would be useful to evaluate the association between cancer diagnosis and persistence of treatment of other chronic diseases.