Side Effects, Self-Management Activities, and Adherence to Oral Anticancer Agents.

PURPOSE

There are growing concerns about patients' adherence to oral anticancer agents (OAAs), and the need for patients to engage in self-management of OAA-related side effects. We assessed associations among adherence, severity of side effects, and effectiveness of self-management of side effects in patients taking capecitabine.

METHODS

Adherence to capecitabine at 6 weeks was measured by the Medication Event Monitoring System among 50 patients with gastrointestinal cancers. Severity of side effects related to capecitabine and effectiveness of self-management of side effects were captured using the Modified Self-Care Diary at the time of enrollment and weekly for 6 weeks. Spearman's correlation, Mann-Whitney -tests, and multiple linear regression were conducted, <0.05.

RESULTS

Overall mean adherence rate was 85.4±14.1%. Adherence rate was not significantly correlated to the mean severity of total side effects at any time point and was correlated with the mean effectiveness of self-management of total side effects only at week 2 (=0.29, =0.04). However, adherence rate was associated with the mean severity of one specific side effect, diarrhea, at 6 weeks (=0.36, =0.01) and marginally correlated to the mean effectiveness of self-management of diarrhea at 6 weeks (=0.28, =0.05). Mean severity of diarrhea at 6 weeks was an independent predictor of adherence rate (=4.97, =0.01), with the control of age (=0.52, =0.002), number of outpatient medications (=1.12, =0.007), health literacy (=2.53, =0.04), diagnosis of colorectal cancer (=11.6, =0.03), and capecitabine in combination with other chemotherapies (=16.8, =0.001) in the model.

CONCLUSION

This pilot study suggests ongoing examination of both severity and effectiveness of self-management of side effects in future studies of adherence to OAAs is merited. There is a need for future studies with larger sample sizes that explore the complex relationships among adherence, severity of side effects, and effectiveness of self-management of side effects in OAA therapy.