Regression Analysis of Non-iatrogenic Factors That Determine Adherence to Radiation Therapy

The aim of this study is to explore non-medical factors that determine withdrawal from radiation therapy. Data from 2,643 patients who received radiotherapy in our Hospital from March 2010 to March 2012 were collected. Using gender, age, stage of the disease, Karnofsky score, aim of radiation therapy, therapy technique, vocation, medical insurance, and educational status as variables, 43 patients who terminated radiation therapy due to non-medical causes and 43 who completed the recommended course in the same period of time were, respectively, allocated to study and control groups. Univariate and 1:1 multivariate conditional logistic regression analyses were used to determine the risk facts for treatment withdrawal. Forty-three patients who withdrew from the therapy received at least one and maximally 26 therapy sessions (median of seven). A significant part of therapy withdrawals occurred during the first week and accounted for 37 % of therapy withdrawals. Univariate analysis showed that vocation, medical insurance, educational status, stage of the disease, Karnofsky score, aim, and technique of radiation therapy were significant determinants of therapy withdrawal. Furthermore, medical insurance status and stage of the disease were also found to be determinants in the multivariate regression analysis. Medical insurance and stage of the disease were found to be the major determinants that affect withdrawal from radiation therapy.