Reliability of collecting colorectal cancer stage information from pathology reports and general practitioners in Queensland.

To investigate the reliability of collecting colorectal stage information from pathology reports and general practitioners in Queensland, Australia. A longitudinal study of colorectal cancer survivors conducted in 2003 and 2004 (n=1966, response rate=57%) obtained stage information from clinical specialists (n=1334), general practitioners (GP) (n=1417) and by extracting stage from pathology reports (n=1484). Reliability of stage information was determined by comparing stage from GPs and pathology reports with that reported by the clinical specialists, using a weighted kappa. GPs and pathology reports each had a similar level of agreement with clinical specialists, with kappa scores of 0.77 (0.75-0.80) (n=1042) and 0.78 (0.75-0.81) (n=1152), respectively. Results were similar when restricting to records staged by all three methods (n=847). GPs had similar levels of agreement with clinical specialists within each stage, although pathology reports tended to under-stage patients in Stage D (0.37). Collapsing stage into two categories (A or B, C or D) increased the reliability estimates from the pathology reports to 0.91 (0.88-0.93), but there was little change in GP estimates 0.79 (0.75-0.83). Extractions from pathology reports are a valid source of broad stage information for colorectal cancer. In the absence of clinical stage data, access to pathology records by population-based cancer registries enables a more accurate assessment of survival inequalities in colorectal cancer survival.