Adherence assessment of patients with metastatic solid tumors who are treated in an oncology group practice

Due to the increase of oral agents nonadherence is an emerging challenge in cancer care. We evaluated how well different assessments match and how adherence could be measured in routine care. For this purpose patients suffering from metastatic solid tumors who were treated with oral anticancer drugs in an oncology group practice were surveyed. Attending oncologists answered a questionnaire, too, and a retrospective analysis of prescription data was conducted. Caregivers who were eligible for an interview were surveyed additionally. 128 patients (70 % female) with a median age of 69 years (36-88) took part, 95 % of all approached patients. 56 % suffered from metastatic breast cancer, 44 % from other metastatic solid tumors. 65 caregivers (60 % female) with a median age of 62 years (21-82) were interviewed as well. Patients were assessed in 84 % as very reliable in medication-taking by their oncologists. This high adherence rate was supported by patients, caregivers and prescription data. However, concordance between assessments of patients, caregivers and oncologists was not substantial. Our method of considering different perspectives to assess adherence has to be improved and validated but could help to evaluate adherence with oral cancer therapy in routine care.