OXCHECK 1995.

Methods	Design: RCT by household Setting: 5 primary care practices in Luton and Dunstable, Bedfordshire, England. 3 practices with > 10,000 patients in Luton, 2 practices with ˜7500 patients; 1 in Luton, 1 in Dunstable Dates: Practice registers screened in 1988, participants randomised in 1988, intervention group health check in 1989 ‐ 1990, control group health check 1992 ‐ 1993 Follow‐up: 3 years (intervention group)
Participants	N randomised: 11,090 (to 4 groups, only 2 were analysed in publication) Intervention n = 2776 Control: n = 2783 Potential participants were all those on the practice register, men or women, aged 35 ‐ 64 on 1/1/1989. Some of these (338) were later deemed “not eligible for a health check” but exclusion criteria not stated. For intervention group: mean prevalence of chest pain 10% in men, 8% in women (using WHO questionnaire, “indicates angina or infarction”) Hypertension, diabetes or IHD mean prevalence 14% of men, 15% of women
Interventions	Setting: Primary care Intervention: Health check: details of personal and family history of IHD, stroke, HTN, DM, cancer, smoking, dietary intake; measurement of height/weight (BMI calculated), BP, serum cholesterol. Nurses were instructed to counsel participants about risk factors, ascertaining their views and negotiating priorities and targets for risk reduction, with follow‐up by mutual agreement between nurse and participant. Set protocols for repeat measurement were laid down for high blood pressure and hyperlipidaemia. The intervention group were further randomised to receive annual re‐examinations (n = 110) or a single return visit at 3 years (n = 1105). Control: No intervention during study period (had initial health check at the same time as the 3‐year follow‐up for intervention group) % men: control group 885/1916 (46.2%); intervention group 987/2205 (44.8%) Age: not reported, states groups did not differ significantly in the distribution if age or social class
Outcomes	BP, lipid levels (total cholesterol), costs, attendance rates, case‐finding rates
Notes	Intervention: 1660/2776 attended follow‐up (raw 40.2% loss), stated 18.3% loss when removing those who left the practice area Control: 1916/2783 attended follow‐up (raw 31.2% loss), stated 18.7% loss when removing those who left the practice area
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not reported
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Not reported, but outcomes objective so low risk of bias
Incomplete outcome data (attrition bias) All outcomes	Low risk	Losses reported and similar between groups
Selective reporting (reporting bias)	Unclear risk	Unclear
Other bias	Unclear risk	Unclear