Treatment adherence of cancer patients to orally administered chemotherapy: insights from a Greek study using a self-reported questionnaire.

Purpose: The aim of this prospective observational study was to investigate the patterns of treatment adherence to orally administered chemotherapy of patients being treated for cancer.

Methods: Patients were asked to participate in the survey during their visits to the study centers' pharmacists or doctors to obtain their oral medication from April 2008 until May 2009. The data were collected using a self-reported anonymous 7-page long questionnaire, which contained questions about their demographic profile, disease and treatment characteristics, and side-effects and adherence information, both intentional and nonintentional.

Results: 99 Patients completed the questionnaire. Missing values ranged from 1% to 8%. Unintended nonadherence to therapy was reported by 19 patients. The most important factor correlating with unintended nonadherence was the patient's belief regarding treatment effectiveness since only 16.7% of the patients believing that their treatment is effective reported nonadherence as opposed to 62.5% for those that did not believe that treatment is effective (p=0.03). Intentional nonadherence was reported by 14 patients The most important factor correlating to intentional nonadherence was time since disease diagnosis, as nonadherence was reported by 33.3% of the patients having the disease less than 6 months, compared to 16.7% for those between 6 and 24 months and 8.3% for those between 2 and 5 years (p=0.01).

Conclusion: Greek patients seem to have similar nonadherence pattern as in other countries. Confidence in treatment efficacy appeared as a significant adherence determinant.