[Development of a risk calculator for drug compliance in treated hypertensives: The FLAHS Compliance Calculator]

Abstract

Objective: To investigate the determinants of non-compliance with antihypertensive treatments among participants in the FLAHS 2015 survey and to develop a risk calculator for drug compliance in a hypertensive population.

Methods: The FLAHS surveys are carried out by self-questionnaire sent by mail to individuals from the TNS SOFRES (representative panel of the population living in metropolitan France) sampling frame. In 2015, FLAHS was performed in subjects aged 55years and older. Using the Girerd questionnaire, the "perfect observance" was determined for a score of 0 and "nonobservance" for a score of 1 or higher. A Poisson regression was conducted in univariate and multivariate to estimate risk ratios for each determinant. A non-compliance risk calculator is constructed from multivariate analysis. A Poisson regression was performed in univariate and multivariate to estimate risk ratios. For each sex, a probability table is produced from the equation of the multivariate analysis and then the calculation of a nonobservance probability ratio (PR) using the profile with the best probability as a reference. Each subject is then classified into one of the three classes of risk of non-compliance: low (PR <1.5), high (PR>=2) and intermediate (PR>=1.5 and <2).

Results: The survey included 6379 subjects and analysis based on 2370 treated hypertensives. The onset of treatment was less than 2years in 7% of subjects and the median follow-up duration of treatment was 10years. Perfect compliance was observed in 64% of subjects. Independent determinants of non-compliance are: male sex, young age, number of antihypertensive tablet, treatment for a metabolic disease (diabetes, dyslipidemia), presence of other chronic illness, secondary prevention of cardiovascular disease. To get the risk class of nonobservance a web page is available at http://www.comitehta.org/flahs-observance-hta/.

Conclusion: The development of the FLAHS Compliance Test is a tool whose use is possible during an office visit. Its free availability for French doctor will be one of the actions undertaken as part of the "call for action for adherence in hypertension" proposed by the French League Against Hypertension in 2017.

Keywords: Antihypertensive drugs; Arterial hypertension; Drug compliance; Enquête FLAHS; FLAHS survey; Hypertension artérielle; Médicaments antihypertenseurs; Observance.