Influence of Patient Characteristics on Success of Ambulatory Blood Pressure Monitoring

Abstract

To examine the influence of specific patient characteristics on the success of ambulatory blood pressure monitoring (ABPM). Retrospective analysis. University-affiliated family care center. Five hundred thirty patients (mean age 52.7 yrs, range 14-90 yrs) who were undergoing ABPM between January 1, 2001, and July 1, 2007. Specific patient characteristics were identified through an electronic medical record review and then examined for association with ABPM session success rate. These patient characteristics included age, sex, weight, height, body mass index (BMI), occupation, clinic blood pressure, travel distance to clinic, and presence of diabetes mellitus or renal disease. The percentage of valid readings obtained during an ABPM session was analyzed continuously (0-100%), whereas overall session success was analyzed dichotomously (0-79% or 80-100%). Univariate and multivariate regression analyses were performed to examine the influence of patient characteristics on the percentage of valid readings and the overall likelihood of achieving a successful session. In the 530 patients, the average percentage of valid readings was 90%, and a successful ABPM session (>or= 80% valid readings) was obtained in 84.7% (449 patients). A diagnosis of diabetes was found to negatively predict ABPM session success (continuous variable analysis, p=0.019; dichotomous variable analysis, odds ratio [OR] 0.45, 95% confidence interval [CI] 0.23-0.87, p=0.019), as did renal disease (continuous variable analysis, p=0.006; dichotomous variable analysis, OR 0.39, 95% CI 0.17-0.90, p=0.027) and increasing BMI (continuous variable analysis, p<0.001; dichotomous variable analysis, OR 0.78, 95% CI 0.65-0.93, p=0.005). Renal disease and BMI remained significant predictors in adjusted analyses. For most patients, ABPM was successful; however, elevated BMI and renal disease were associated with less complete ABPM session results. Adaptation and individualization of the ABPM process may be necessary to improve results in these patients.