Background: Large variation in measures of diagnostic activity have been described previously between English general practices, but related predictors remain understudied.

Objective: To examine associations between general practice population and characteristics, with the use of urgent referrals for suspected cancer, and use of endoscopy.

Methods: Cross-sectional observational study of English general practices. We examined practice-level use (/1000 patients/year) of urgent referrals for suspected cancer, gastroscopy, flexible sigmoidoscopy and colonoscopy. We used mixed-effects Poisson regression to examine associations with the socio-demographic profile of practice populations and other practice attributes, including the average age, sex and country of qualification of practice doctors.

Results: The socio-demographic characteristics of registered patients explained much of the between-practice variance in use of urgent referrals (32%) and endoscopic investigations (18%-27%), all being higher in practices with older and more socioeconomically deprived patients. Practice-level attributes explained a substantial amount of between-practice variance in urgent referral (19%) but little of the variance in endoscopy (3%-4%). Adjusted urgent referral rates were higher in training practices and those with younger GPs. Practices with mean doctor ages of 41 and 57 years (at the 10th/90th centiles of the national distribution) would have urgent referral rates of 24.1 and 19.1 / 1000 registered patients, p<0.001.

Conclusion: Most between-practice variation in use of urgent referrals and endoscopies seems to reflect health need. Some practice characteristics, such as the mean age of GPs, are associated with appreciable variation in use of urgent referrals, though these associations do not seem strong enough to justify targeted interventions.