Beliefs about medicines in relation to the initiation of cardiovascular preventive medications during a 3 year follow-up period after inclusion in the VIPVIZA trial: a cohort study.

Abstract

To investigate if beliefs about medicines affect the time to the initiation of cardiovascular preventive medications during a 3 year follow-up period. A questionnaire and register-based cohort study. Primary care in Sweden, in which people 40, 50 and 60 years old underwent risk factor screening and individual health promotion within the Västerbotten intervention programme (VIP). People at low/medium risk of cardiovascular disease (CVD) according to the risk factor screening were included in the <b>VI</b>suali<b>Z</b>ation of asymptomatic <b>A</b>therosclerotic disease for optimum cardiovascular prevention-a population-based Pragmatic Randomised Open Blinded End-point trial (PROBE) nested in the <b>V</b>ästerbotten <b>I</b>ntervention <b>P</b>rogramme (VIPVIZA), aiming at improved primary prevention of CVD. People participating in the VIPVIZA 3 year follow-up (n=3167 (89.7%)), receiving the Beliefs about medicines questionnaire (BMQ) (n=2314 (73.1%)) and with complete answers to at least one subscale in the BMQ general (n=2258 (97.6%)) were included. Moreover, only those 60 years old at baseline (n=2073 (58.7%)) and without antihypertensive and/or lipid-lowering drugs (n=1769 (50.1%)) 6 months prior to inclusion in the VIPVIZA trial were included. Accordingly, the final study population comprised 888 people without antihypertensive medicines and 1185 without lipid-lowering drugs, respectively. The primary outcome was time to the binary event of initiating antihypertensives or lipid-lowering agents, identified within the time frame from inclusion in the VIPVIZA study until the study participants' 3 year follow-up visit. General beliefs about medicines were assessed according to the BMQ. Cox proportional hazards models, adjusted for sex, were conducted to investigate primary outcome. Participants with stronger general beliefs about medicines being overused had significantly longer time to initiation of antihypertensive drugs in the control group (HR 0.91; 95% CI 0.84 to 0.996) but not in the intervention group (HR 1.05; 95% CI 0.95 to 1.16). No significant associations were found between beliefs about medicines and initiation of lipid-lowering treatment. A more negative perception of drugs being overused was significantly associated with delayed initiation of antihypertensive drug treatment. Our results suggest that the VIPVIZA intervention may overbridge negative perceptions and affect the initiation of antihypertensive medications in a positive manner. NCT01849575 (date of registration: 8 May 2013).