The Effects of a Co-design Based Invitation Strategy on Participation in a Preventive Health Check Program: A Randomized Controlled Trial (Preprint)
BACKGROUND Primary-care-based preventive programs that aim to reduce morbidity and mortality from lifestyle-related diseases often suffer from low to moderate participation rates. Improving participation rates is essential to clinical effect and cost effectiveness. In 2016-2017 we conducted the first pilot study (TOF pilot1) testing a primary-care-based preventive program (the TOF intervention) comprising systematic identification of individuals at risk of lifestyle-related diseases, and subsequent targeted preventive services offered to the at-risk population. A total of 40.2% of the invited patients consented to take part in the study with the highest participation rates obtained among women and patients with higher income, education, and employment. OBJECTIVE The aim of this study was to evaluate the effect of a revised invitation strategy targeting men and patients of low educational attainment on overall participation rate and participant demography. METHODS This study was embedded in the second pilot study (initiated in October 2018) testing an adjusted TOF intervention (TOF pilot2). The revised invitation strategy comprised a pre-notification postcard and a new invitation targeting men and patients of low educational attainment. The new invitation was developed in a co-design process involving communication professionals and target group representatives. The study sample consisted of 4633 patients aged 29-59 years and residing in two municipalitites in the Region of Southern Denmark. Eligible patients were randomly assigned to four invitation groups receiving either 1) The original invitation used in TOF pilot1 (Control group), 2) The original invitation and the pre-notification postcard, 3) The new, revised invitation and the pre-notification postcard, or 4) The new invitation only. RESULTS Overall, 2171 (46.9%) patients consented to participate. Compared to receiving the original invitation alone, participation rates increased significantly for those groups who received the new revised invitation alone (p<.001), the new invitation with the pre-notification postcard (p<.001), and the original invitation with the pre-notification postcard (p<.001). Participation across the three intervention groups was increased among women as well as men, patients of high as well as low educational attainment and patients of low as well as higher family income. The largest relative increase in participation was seen among males, patients with low educational attainment, and patients with low family income. No significant increase in participation was detected among unemployed patients and patients of non-Danish origin. CONCLUSIONS The results showed that significant improvements in participation rates can be obtained from pre-notification postcards and invitations that have undergone a co-design process, involving communication professionals and target group representatives. Although firm conclusions can not be made from the present study, the apparent increased effect on participation among men and patients of low socioeconomic status may be relevant in programs that aim to reduce inequality in health. In order to reach the most socioeconomically disadvantaged groups, the invitation strategy should probably be combined with other more individual-oriented recruitment approaches. CLINICALTRIAL Clinical Trial Gov (NCT03913585)