The impact of community-based prevention on quality of life-The necessity to control for general health trends the Northern Sweden MONICA study in 2014

Background: The Västerbotten intervention program (VIP), is a public health promotion program in northern Sweden with the aim of preventing cardiovascular disease. Positive effects have been reported although the evidence is not unequivocal. Since only historical controls have been used, effects from other sources than the program have largely been uncontrolled for and health related quality of life (HRQoL) has not been evaluated. Purpose: By using the neighbouring county of Norrbotten (NB) as the reference population, we compare HRQoL in Västerbotten (VB) and in NB. Methods: In 2014 the Northern Sweden survey, Monitoring of Trends and Determinants in Cardiovascular Disease (MONICA), examined a random sample from the two counties. HRQoL was measured with the EQ-5D-3L. In total, 1112 subjects aged 40-74 years participated, 516 in VB and 594 in NB. Differences in mean QoL between VB and NB were analysed via Student's t-test and the Pearson chi-square test. Results: Average HRQoL measured by the EQ-5D-index was 0.798 in VB and 0.811 in NB, a difference of 0.013 (p = 0.2, CI -0.009 to 0.036). For subjects aged 45-54 years, the HRQoL was lower in VB than in NB, a difference of 0.048 (p = 0.041; CI 0.002 to 0.0094). Men had higher HRQoL than women, and university educated had higher HRQoL than those without university education. EQ-VAS showed similar results. Subjects from NB and from VB did not differ regarding age, gender and level of education. In NB, HRQoL decrease with age, a pattern not seen in VB. Conclusions: We found similar levels of HRQoL in VB and in NB