title: Prevalence of hypertension and its treatment among adults presenting to primary health clinics in rural Zambia: analysis of an observational database.
abstract: BACKGROUND
  Hypertension constitutes a growing burden of illness in developing countries like Zambia. Adequately screening and treating hypertension could greatly reduce the complications of stroke and coronary disease. Our objective was to determine the prevalence of hypertension and identify current treatment practices among adult patients presenting for routine care to rural health facilities in the Better Health Outcomes through Mentoring and Assessments (BHOMA) project.
  
  
  METHODS
  We conducted a retrospective analysis of routinely collected clinical data from 46 rural government clinics in Zambia. Our analysis cohort comprised patients ≥ 25 years with recorded blood pressure measurements, who sought care at primary health centers. Consistent with prior research, in our primary analysis, we only included data from first visits. Hypertension was defined as a systolic blood pressure ≥140 mmHg, or diastolic blood pressure ≥90 mmHg, or reported use of antihypertensive medication. A sensitivity analysis was performed using median blood pressure for individuals with multiple visits.
  
  
  CONCLUSIONS
  From January 2011 to December 2014, 116,130 first visits by adult patients met eligibility criteria. The crude prevalence of hypertension by onsite measurement or reported use of antihypertensive medication was 23.1% [95% CI: 22.8-23.3] (23.6% in females, 22.3% in males). The age standardized prevalence of hypertension across participating sites was 28.0 [95% CI: 27.7-28.3] (29.7% in females, 25.8% in males). Sensitivity analysis revealed a similar prevalence using data from all visits. Only 5.6% of patients had a diagnosis of hypertension documented in their medical record. Among patients with hypertension, only 18.0% had any antihypertensive drug prescribed, with nifedipine (8.9%), furosemide (8.3%), and propranolol (2.4%) as the most common.
  
  
  CONCLUSIONS
  Age standardized prevalence of hypertension in rural primary health clinics in Zambia was high compared to other studies in rural Africa; however, we diagnosed hypertension with only one measurement and this may have biased our findings. Future efforts to improve hypertension control should focus on population preventive care and primary healthcare provider education on individual management.
authors.affiliation: Primary Care and Health Systems Department, Center for Infectious Disease Research Zambia, Lusaka, Zambia. lilyyan@stanford.edu.|Stanford University School of Medicine, Stanford, California, USA. lilyyan@stanford.edu.
authors.forename: Lily D
authors.initials: LD
authors.lastname: Yan
authors.affiliation: Primary Care and Health Systems Department, Center for Infectious Disease Research Zambia, Lusaka, Zambia. benjamin_chi@med.unc.edu.|Department of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA. benjamin_chi@med.unc.edu.
authors.forename: Benjamin H
authors.initials: BH
authors.lastname: Chi
authors.affiliation: Primary Care and Health Systems Department, Center for Infectious Disease Research Zambia, Lusaka, Zambia. ntazana.sindano@cidrz.org.
authors.forename: Ntazana
authors.initials: N
authors.lastname: Sindano
authors.affiliation: Primary Care and Health Systems Department, Center for Infectious Disease Research Zambia, Lusaka, Zambia. samuel.bosomprah@cidrz.org.|Department of Biostatistics, School of Public Health, University of Ghana, Accra, Ghana. samuel.bosomprah@cidrz.org.
authors.forename: Samuel
authors.initials: S
authors.lastname: Bosomprah
authors.affiliation: Department of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA. jeffrey_stringer@med.unc.edu.
authors.forename: Jeffrey Sa
authors.initials: JS
authors.lastname: Stringer
authors.affiliation: Primary Care and Health Systems Department, Center for Infectious Disease Research Zambia, Lusaka, Zambia. roma.chilengi@cidrz.org.|Department of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA. roma.chilengi@cidrz.org.
authors.forename: Roma
authors.initials: R
authors.lastname: Chilengi
mesh_terms: D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001795:Blood Pressure Determination / Q000706:statistics & numerical data; D019049:Developed Countries; D005260:Female; D006304:Health Status; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D012424:Rural Population / Q000706:statistics & numerical data*; D015024:Zambia / Q000453:epidemiology
chemical_list: D000959:Antihypertensive Agents