To assess health care characteristics for hypertensive patients and their association with uncontrolled hypertension in a primary care outpatient clinic.Cross-sectional.A review was conducted of 50% of 8080 (n= 4040) files. Patient, physician and primary health care clinic characteristics were recorded.The factors associated with uncontrolled hypertension were: age (OR, 1.43; CI95% : 1.015-1.030), BMI (OR, 1.03; CI95%: 1.02-1.05), creatinine serum levels (OR, 1.16; CI95%: 1.03-1.30), three or more different antihypertensive drugs (OR, 1.48; CI95%: 1.31-1.07), to be treated by a physician with more than 20 years of medical practice (OR, 1.21; CI95%; 1.06-1.39) or by a non-specialist physician (OR, 1.43; CI95%: 1.20-1.71) and to be treated in the morning shift (OR, 1.21; CI95%: 1.07- 1.56).Hypertension is well-controlled in the majority of patients. Patient-related factors are important in uncontrolled hypertension; however, health care system characteristics also play an important role.
