Comparing primary and secondary health-care use between diagnostic routes before a colorectal cancer diagnosis: cohort study using linked data.

BACKGROUND: Survival in cancer patients diagnosed following emergency presentations is poorer than those diagnosed through other routes. To identify points for intervention to improve survival, a better understanding of patients' primary and secondary health-care use before diagnosis is needed. Our aim was to compare colorectal cancer patients' health-care use by diagnostic route. METHODS: Cohort study of colorectal cancers using linked primary and secondary care and cancer registry data (2009-2011) from four London boroughs. The prevalence of all and relevant GP consultations and rates of primary and secondary care use up to 21 months before diagnosis were compared across diagnostic routes (emergency, GP-referred and consultant/other). RESULTS: The data set comprised 943 colorectal cancers with 24% diagnosed through emergency routes. Most (84%) emergency patients saw their GP 6 months before diagnosis but their symptom profile was distinct; fewer had symptoms meeting urgent referral criteria than GP-referred patients. Compared with GP-referred, emergency patients used primary care less (IRR: 0.85 (95% CI 0.78-0.93)) and urgent care more frequently (IRR: 1.56 (95% CI 1.12; 2.17)). CONCLUSIONS: Distinct patterns of health-care use in patients diagnosed through emergency routes were identified in this cohort. Such analyses using linked data can inform strategies for improving early diagnosis of colorectal cancer.