Enhanced invitation methods and uptake of health checks in primary care: randomised controlled trial and cohort study using electronic health records

Background: A national programme of health checks to identify risk of cardiovascular disease (CVD) is being rolled out but is encountering difficulties because of low uptake. Objective: To evaluate the effectiveness of an enhanced invitation method using the question-behaviour effect (QBE), with or without the offer of a financial incentive to return the QBE questionnaire, at increasing the uptake of health checks. The research went on to evaluate the reasons for the low uptake of invitations and compare the case mix for invited and opportunistic health checks. Design: Three-arm randomised trial and cohort study. Participants: All participants invited for a health check from 18 general practices. Individual participants were randomised. Interventions: (1) Standard health check invitation only; (2) QBE questionnaire followed by a standard invitation; and (3) QBE questionnaire with offer of a financial incentive to return the questionnaire, followed by a standard invitation. Main outcome measures: The primary outcome was completion of the health check within 6 months of invitation. A p-value of 0.0167 was used for significance. In the cohort study of all health checks completed during the study period, the case mix was compared for participants responding to invitations and those receiving 'opportunistic' health checks. Participants were not aware that several types of invitation were in use. The research team were blind to trial arm allocation at outcome data extraction. Results: In total, 12,459 participants were included in the trial and health check uptake was evaluated for 12,052 participants for whom outcome data were collected. Health check uptake was as follows: standard invitation, 590 out of 4095 (14.41%); QBE questionnaire, 630 out of 3988 (15.80%); QBE questionnaire and financial incentive, 629 out of 3969 (15.85%). The increase in uptake associated with the QBE questionnaire was 1.43% [ 95% confidence interval (CI) -0.12% to 2.97%; p = 0.070] and the increase in uptake associated with the QBE questionnaire and offer of financial incentive was 1.52% (95% CI -0.03% to 3.07%; p = 0.054). The difference in uptake associated with the offer of an incentive to return the QBE questionnaire was -0.01% (95% CI -1.59% to 1.58%; p = 0.995). During the study period, 58% of health check cardiovascular risk assessments did not follow a trial invitation. People who received an 'opportunistic' health check had greater odds of a >= 10% CVD risk than those who received an invited health check (adjusted odds ratio 1.70, 95% CI 1.45 to 1.99; p < 0.001). Conclusions: Uptake of a health check following an invitation letter is low and is not increased through an enhanced invitation method using the QBE. The offer of a 5 pound incentive did not increase the rate of return of the QBE questionnaire. A high proportion of all health checks are performed opportunistically and not in response to a standard invitation letter. Participants receiving opportunistic checks are at higher risk of CVD than those responding to standard invitations. Future research should aim to increase the accessibility of preventative medical interventions to increase uptake. Research should also explore the wider use of electronic health records in delivering efficient trials.