Identification of patient-related, healthcare-related and knowledge-related factors associated with inadequate blood pressure control in outpatients: a cross-sectional study in Serbia

OBJECTIVES: To determine rate of blood pressure (BP) control and to analyse patient-related, medication-related and healthcare system-related factors associated with poor BP control in outpatients with hypertension (HT). DESIGN: Cross-sectional study. SETTING: Two study sites with different levels of healthcare (primary healthcare (PHC) and secondary level of healthcare (SHC)) in Vojvodina, Northern Serbia. PARTICIPANTS: A total of 581 patients (response rate 96.8%) visiting their primary care physician between July 2019 and June 2020 filled out a pretested semistructured questionnaire and had a BP reading during their regular appointments. PRIMARY AND SECONDARY OUTCOME MEASURES: Data on demographics, medication, BP control (target systolic BP≤140 mm Hg and∕ or diastolic BP≤90 mm Hg) and knowledge on HT was collected. Based on the median of knowledge score, patients were classified as having poor, average and adequate knowledge. RESULTS: Majority of the respondents (74.9%) had poorly controlled BP and had HT longer than 10 years. Larger number of patients at PHC site was managed with monotherapy while at the SHC majority received three or more antihypertensive drugs. Respondents from SHC showed a significantly lower knowledge score (9, 2–15) compared with the respondents from PHC (11, 4–15, p=0.001). The share of respondents with adequate knowledge on HT was significantly higher in the group with good BP control (26% and 9.2%, respectively). In a multivariate regression analysis, factors associated with poor BP control were knowledge (B=−1.091; p<0001), number of drugs (B=0536; p<0001) and complications (B=0898; p=0004). CONCLUSIONS: Poor BP control is common in outpatients in Serbia, irrespective of the availability of different levels of healthcare. Patients with poor knowledge on HT, with complications of HT and those with multiple antihypertensive drugs, were at particular risk of poor BP control. Our study could serve as a basis for targeted interventions to improve HT management.