Waiting time for radiation therapy in breast cancer patients in Quebec from 1992 to 1998: a study of surgically treated breast cancer patients in Quebec documents and helps to explain increased waiting times for radiation therapy.

BACKGROUND: This study was conducted among surgically treated breast cancer patients in Quebec to determine waiting time between surgery and post-operative radiation therapy and factors influencing it.
METHODS: Records of fee-for-service claims and hospitalizations were obtained for all women who, between 1992 and 1998, underwent an invasive procedure for non-metastatic breast cancer. Waiting time was defined as the time between either the last surgical procedure or the last cycle of chemotherapy and the initiation of radiation therapy. Hierarchical linear regression models were used to identify predictors of waiting time.
RESULTS: Over seven years, 29,072 episodes of breast cancer treatments were identified, of which 17,684 included radiation therapy. The number of cases increased by 5.5% per year, but concurrent broadening of indications for radiation therapy led to an increase in the number of breast cancer patients receiving radiation therapy of 9% per year. In hierarchical linear modelling, comparing 1998 to 1992, median waiting time increased by 63% (95% confidence interval [CI] 35%-97%) in patients not receiving chemotherapy and by 35% (95% CI 3%-88%) in patients receiving chemotherapy. Other predictors of shorter waiting times were localized cancer stage, breast-conserving surgery, early consultation with a radiation oncologist, having surgery in a centre with a radiation therapy facility, living close to a radiation therapy facility and living in a higher socio-economic area.
INTERPRETATION: Using administrative databases to evaluate waiting times is feasible. Explanations of the increased waiting time include increased demand, insufficient resources and changes in the indications for breast-conserving surgery and radiation therapy.