Effect of specialized diagnostic assessment units on the time to diagnosis in screen-detected breast cancer patients

BACKGROUND: The duration of the cancer diagnostic process has considerable influence on patients' psychosocial well-being. Breast diagnostic assessment units (DAUs) in Ontario, Canada are designed to improve the quality and timeliness of care during a breast cancer diagnosis. We compared the diagnostic duration of patients diagnosed through a DAU vs usual care (UC). METHODS: Retrospective population-based cohort study of 2499 screen-detected breast cancers (2011) using administrative health-care databases linked to the Ontario Cancer Registry. The diagnostic interval was measured from the initial screen to cancer diagnosis. Diagnostic assessment unit use was based on the biopsy and/or surgery hospital. We compared the length of the diagnostic interval between the DAU groups using multivariable quantile regression. RESULTS: Diagnostic assessment units had a higher proportion of patients diagnosed within the 7-week target compared with UC (79.1% vs 70.2%, P<0.001). The median time to diagnosis at DAUs was 26 days, which was 9 days shorter compared with UC (95% CI: 6.4–11.6). This effect was reduced to 8.3 days after adjusting for all study covariates. Adjusted DAU differences were similar at the 75th and 90th percentiles of the diagnostic interval distribution. CONCLUSIONS: Diagnosis through an Ontario DAU was associated with a reduced time to diagnosis for screen-detected breast cancer patients, which likely reduces the anxiety and distress associated with waiting for a diagnosis.