Predictors of the Home-Clinic Blood Pressure Difference: A Systematic Review and Meta-Analysis

BACKGROUND Patients may have lower (white coat hypertension) or higher (masked hypertension) blood pressure (BP) at home compared to the clinic, resulting in misdiagnosis and suboptimal management of hypertension. This study aimed to systematically review the literature and establish the most important predictors of the home-clinic BP difference. METHODS A systematic review was conducted using a MEDLINE search strategy, adapted for use in 6 literature databases. Studies examining factors that predict the home-clinic BP difference were included in the review. Odds ratios (ORs) describing the association between patient characteristics and white coat or masked hypertension were extracted and entered into a random-effects meta-analysis. RESULTS The search strategy identified 3,743 articles of which 70 were eligible for this review. Studies examined a total of 86,167 patients (47% female) and reported a total of 60 significant predictors of the home-clinic BP difference. Masked hypertension was associated with male sex (OR 1.47, 95% confidence interval (CI) 1.18-1.75), body mass index (BMI, per kg/m(2) increase, OR 1.07, 95% CI 1.01-1.14), current smoking status (OR 1.32, 95% CI 1.13-1.50), and systolic clinic BP (per mm Hg increase, OR 1.10, 95% CI 1.01-1.19). Female sex was the only significant predictor of white coat hypertension (OR 3.38, 95% CI 1.64-6.96). CONCLUSIONS There are a number of common patient characteristics that predict the home-clinic BP difference, in particular for people with masked hypertension. There is scope to incorporate such predictors into a clinical prediction tool which could be used to identify those patients displaying a significant masked or white coat effect in routine clinical practice.