Impact of health-promoting text messages on cardiovascular risk: findings from a randomized controlled trial in primary care

Abstract

Introduction – Cardiovascular disease (CVD) prevention is a major public health priority. Text message interventions promoting a healthy lifestyle can contribute to improved blood pressure in patients with hypertension, however the effect on other metabolic outcomes and broader CVD risk factor control are less studied. We aimed to investigate the effect of health-promoting text messages on metabolic- and multiple CVD risk factors among Swedish primary care patients with hypertension. Methods – This was a multi-center randomized controlled trial including a total of 401 participants. Four health-promoting text messages per week were sent to the intervention group (n = 193) for 6 months, with the control group (n = 208) receiving standard care. Data were analyzed according to the intention-to-treat principle. We investigated the intervention effect on metabolic risk factors, change in number of CVD risk factors, and improvements in CVD risk factor control at follow-up compared to baseline. Results – There was no difference between the intervention and the control group in improved CVD risk profiles, although both groups had decreased their number of CVD risk factors at follow-up. However, in subgroup analyses both sedentary participants and those with poor self-rated health demonstrated significant improvements in CVD risk factor control between baseline and follow-up in the intervention compared with the control group (Z = -2.551, p = 0.01; Z = −2.043, p = 0.041). Furthermore, the intervention group had a modest reduction in HbA1c (−0.61 mmol/L, p = 0.04), with limited clinical impact. Discussion – Health-promoting text messages did not reduce the number of CVD risk factors or improve the overall risk profile in the intervention group compared to control but showed a small effect among participants with sedentary lifestyle or poor self-rated health. Its overall effect on metabolic risk including HbA1c was limited. Still, modest effects on CVD risk factors may have important public health implications, especially in targeted groups. Clinical trial registration – ClinicalTrials.gov, identifier NCT04407962.