Effectiveness of letters to patients with or without Cochrane blogshots on 10-year cardiovascular risk change among women in menopausal transition: 6-month three-arm randomized controlled trial

BACKGROUND: Health information and patient education on lifestyle changes may have a positive effect on the prevention of many chronic conditions, especially cardiovascular diseases (CVDs). We performed a parallel, three-arm randomized controlled trial (RCT) of 6-month educational intervention in a form of letters containing a reminder of the participant’s CVD risk with or without Cochrane blogshots to reduce CVD risk among women aged 45–65 with one or more known CVD risk factors. METHODS: The control group received a letter about their CVD risk at the beginning of the trial. The intervention groups received the initial letter about their CVD risk and remainder letters about their CVD risk every 2 months, with or without Cochrane blogshots: (1) effect of calcium in the prevention of high blood pressure, (2) effect of reducing saturated fat acids in eating habits, and (3) effects of green and black tea in CVD prevention. The primary outcome was CVD risk reduction calculated as the difference between the baseline and 6-month score for a 10-year risk of fatal CVD according to the ACC/AHA guidelines. RESULTS: After both interventions, CVD risk reduction was significantly higher compared to the control group (P < 0.001, Kruskal-Wallis H test). The number of participants who decreased their CV risk was 29% (20/70) in the control group, 69% (48/70) in the group receiving the reminder letters, and 70% (49/70) in the group receiving the reminder letters and blogshots. The number needed to treat to achieve risk reduction was 2.41 (95% CI = 1.77 to 3.78) for letters with a CVD risk reminder and 2.50 (1.81 to 4.03) for letters with a reminder and a blogshot. The group receiving reminder letters with Cochrane blogshots had a significant change in the category of CVD risk, mainly from high to moderate and from moderate to low CVD risk category. CONCLUSIONS: A simple and inexpensive intervention method in a form of letters reminding women about their CVD risk with or without providing additional health information in the form of Cochrane blogshots about interventions for important CVD risk factors may be effective in CVD management and could be considered by primary care providers. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04601558. Retrospectively registered on October 19, 2020 SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12916-022-02555-2.