Purpose — To determine the intermediate-term impact of diagnosis and treatment of ductal carcinoma in situ of the breast (DCIS) on health services utilization, we compared utilization by cases of DCIS to unaffected controls.
Methods — We identified a population-based cohort of Ontario females diagnosed with DCIS between 2010 and 2015. We matched 5 controls without any history of cancer to each case, on the date of diagnosis of the case (the index date), by age, annual mammography history, socioeconomic status, and comorbidity. We identified billing claims and hospital records, during the interval 13 to 60 months prior to, and subsequent to the index date, and computed rates per 100 person-years during both intervals, to conduct a difference-in-differences analysis. We used negative binomial regression to test if the change in rates in health services differed between cases and controls.
Results — Visits with a breast diagnosis code, and claims for breast surgery and imaging, were significantly increased among cases compared to controls (all p values < 0.0001) after DCIS;however, there was no increase in visits for anxiety or depression (RR 1.13 (95% CI 0.97, 1.32, p = 0.11), visits to psychiatrists (RR 1.07 (95% CI 0.82, 1.40) p = 0.6), or hospital procedures other than breast surgery (RR 1.10 (95% CI 0.88, 1.37) p = 0.4).
Conclusions — DCIS is associated with more visits and procedures related to the breast compared to controls following diagnosis and treatment, but other health services utilization and visits related to anxiety and depression were not increased.