Objective: To determine whether age, gender, body mass index (BMI), community pharmacy blood pressure (CPBP), daytime ambulatory BP (ABP) variability, treatment compliance, number of anti-hypertensive drugs and smoking status are factors associated with the community pharmacy white-coat effect (CPWCE) in treated hypertensive patients.
Setting: Eight community pharmacies in Gran Canaria, Spain.
Method: A cross-sectional study was carried out from June 2008 to June 2009. The study included treated hypertensive patients older than 18 years. Patients were excluded if: systolic BP (SBP)/diastolic BP (DBP) ≥ 200/110 mmHg, not-recommended or unable to perform home BP measurements, changes in anti-hypertensive treatment <4 weeks, history of cardiovascular disease <6 months or pregnancy. Blood pressure (BP) was measured by a community pharmacist at 4 visits to the community pharmacy and using ABP monitoring (24 h).
Main outcome measure: The CPWCE was calculated as the difference between the mean BP in the community pharmacy and daytime ABP. Independent predictors of the CPWCE were identified using multivariate linear regression analysis.
Results: Two hundred thirteen patients agreed to participate in the study. After exclusion and withdrawal, 169 patients were included in the analysis. Multiple linear regression analysis for systolic CPWCE revealed only community pharmacy SBP as an independent factor (β = 0.35; P < 0.001). The regression analysis for diastolic CPWCE revealed female gender (β = 4.88; P < 0.001), BMI (β = 0.48; P < 0.001) and community pharmacy DBP (β = 0.24; P < 0.001) as independent determinants.
Conclusion: In this sample of treated hypertensive patients, factors such as gender, community pharmacy DBP and BMI were positively associated and may exert an important influence on the magnitude of the diastolic CPWCE. On the other hand, the CPWCE on SBP increased as the community pharmacy SBP increased.