Abstract 860: Alteration In Blood Pressure Monitoring Technique Impacts Hypertension Treatment
Objectives: Our study investigated the hypothesis that current methods of blood pressure (BP) assessment in an ambulatory clinic result in significantly different BP measurements than those obtained by following the American Heart Association (AHA) recommendations as well as the hypothesis that these BP differences result in treatment variation.
Methods: This was a randomized, cross-over study in 40 patients with hypertension presenting to the UNMH Adult Internal Medicine Clinic. BP was measured in all patients in random order by the clinic staff using the traditional triage method and by the Principal Investigator using the AHA-recommended method. Trained observers documented BP techniques used. Two complete patient profiles were constructed for each patient one with the AHA BP and one with the triage BP. A panel of blinded providers including internists, a cardiologist, and a clinical pharmacist was asked to provide hypertensive treatment recommendations for each profile.
Results: Only DBP differed significantly (77.6 mmHg ± 11.9 vs. 80.4 mmHg ± 10.5; p=0.02) between the triage and AHA methods, respectively. However, individual BP results varied greatly between the two methods. SBP readings differed by ≥5 mmHg in either direction for 68% of patients while 78% of patient’s DBP readings differed by ≥2 mmHg in either direction. Overall, 65% of patients were not at their goal BP when measured with the AHA method compared to 52% with the triage method (p<0.001). Multiple technical errors were seen during the triage method that likely accounted for the variation. Significant differences in treatment between profiles existed. The number of patients with treatment variations between their two profiles ranged from 13% to 23% (p<0.01 for all providers). Kappa scores indicated moderate to substantial clinical agreement between the physicians but only slight agreement between the pharmacist and physicians.
Conclusions: When comparing the two methods of BP measurement, clinically significant differences were observed in a large percentage of patients. This difference significantly impacted hypertension treatment recommendations. Inaccurate BP assessment may lead to inappropriate treatment of hypertension.