OBJECTIVES: Electronic medical records (EMRs) increasingly are being used by outcomes researchers to study the quality of medical care. The study assessed the impact of non-medical switches in ARB therapy on blood pressure (BP) and medical resource utilization including office visits and other antihypertensive medications. METHODS: A retrospective study was conducted using the GE Centricity EMR of a primary care physicians group. Hypertensive patients >18 years, continuously enrolled, and receiving ARB therapy were included. Switch must have occurred after the patient was on the first ARB for at least 60 days. The control group remained on the same ARB and did not switch. A 1:1 matching was done on the duration of initial ARB therapy and presence of diabetes or renal impairment. Demographic characteristics, clinical parameters, ARB use, and office visits were identified. Data was extracted using Microsoft SQL and statistical analyses were conducted using SPSS version 18.0. RESULTS: A total of 4,851 patients (mean age 68.23 years, female 58.1%) were prescribed an ARB between 2004 and 2008 out of which 3,083 (63.6%) stayed on one ARB and 1,768 (36.4%) switched from one ARB to another. Matched pairs of switchers (n=357) and control group (n=357) were then identified. There was no difference in mean baseline systolic BP (SBP) for switchers (143.79+21.22) and control (144.20+22.16) but switchers had higher post-switch SBP (141.06+18.52) than control (137.97+20.58) (p=0.035). More switchers lost control from index to first visit post-index period (11.5%) than control (8.7%). More antihypertensive agents were added in switchers (1.91+1.7) than control (1.02+1.2) in the post-index period (p<0.001). CONCLUSIONS: EMRs have the potential to bridge research with clinical care by providing real-world data. This study demonstrates that non-medical switches may result in loss of BP control and additional medical resource use. Thus, careful consideration should be given before switching therapies for non-medical reasons.