Variations in the investigation of colorectal cancer-related symptoms in Australian primary care: a retrospective cohort study.

Abstract

Colorectal cancer-related symptoms are commonly seen in primary care. Understanding variations in symptom management is crucial for timely care. To examine diagnostic testing patterns for gastrointestinal symptoms associated with colorectal cancer in primary care. Retrospective cohort study using linked primary care data from patients aged ≥40 years presenting with colorectal cancer-related symptoms between 2008 and 2022. The proportion of patients receiving diagnostic actions was assessed, including medications, pathology, imaging, colonoscopy, or specialist referral. Differences in testing by socioeconomic status and subsequent colorectal cancer diagnosis were examined. Among 70 107 patients, 378 (0.5%) were diagnosed with colorectal cancer within 12 months. Abdominal pain (32%; <i>n</i> = 28 455/90 059) and diarrhoea (21%; <i>n</i> = 19 071/90 059) were the most frequent presentations. No investigation or treatment occurred in 20% (change in bowel habit; <i>n</i> = 226/1106) to 50% (constipation; <i>n</i> = 6028/12 128; and diarrhoea; <i>n</i> = 7069/14 122) of patients. Medication-only management was highest for diarrhoea (11%; <i>n</i> = 1547/14 122) and constipation (23%; <i>n</i> = 2847/12 128). Blood or imaging tests were most frequent for abdominal pain (36%; <i>n</i> = 7572/20 956) and abdominal mass (41%; <i>n</i> = 294/718). Colonoscopy or specialist referral was highest for rectal bleeding (67%; <i>n</i> = 4536/6772) and change in bowel habit (60%; <i>n</i> = 662/1106). Investigation likelihood increased with multiple symptoms or repeat visits (odds ratio [OR] 3.40, 95% confidence interval [CI] = 3.16 to 3.65, <i>P</i><0.001). Patients aged ≥80 years were significantly less likely to be investigated or referred (OR 0.53, 95% CI = 0.50 to 0.55, <i>P</i><0.001), and those from more advantaged areas were more likely to be investigated (OR 1.45, 95% CI = 1.38 to 1.53, <i>P</i><0.001). Substantial variation in investigating colorectal cancer-related symptoms may contribute to inequities in diagnostic outcomes.