title: Study Heterogeneity and Estimation of Prevalence of Primary Aldosteronism: A Systematic Review and Meta-Regression Analysis.
abstract: For health care planning and allocation of resources, realistic estimation of the prevalence of primary aldosteronism is necessary. Reported prevalences of primary aldosteronism are highly variable, possibly due to study heterogeneity.
  
  
  
  Our objective was to identify and explain heterogeneity in studies that aimed to establish the prevalence of primary aldosteronism in hypertensive patients.
  
  
  
  PubMed, EMBASE, Web of Science, Cochrane Library, and reference lists from January 1, 1990, to January 31, 2015, were used as data sources.
  
  
  
  Description of an adult hypertensive patient population with confirmed diagnosis of primary aldosteronism was included in this study.
  
  
  
  Dual extraction and quality assessment were the forms of data extraction.
  
  
  
  Thirty-nine studies provided data on 42 510 patients (nine studies, 5896 patients from primary care). Prevalence estimates varied from 3.2% to 12.7% in primary care and from 1% to 29.8% in referral centers. Heterogeneity was too high to establish point estimates (I(2) = 57.6% in primary care; 97.1% in referral centers). Meta-regression analysis showed higher prevalences in studies 1) published after 2000, 2) from Australia, 3) aimed at assessing prevalence of secondary hypertension, 4) that were retrospective, 5) that selected consecutive patients, and 6) not using a screening test. All studies had minor or major flaws.
  
  
  
  This study demonstrates that it is pointless to claim low or high prevalence of primary aldosteronism based on published reports. Because of the significant impact of a diagnosis of primary aldosteronism on health care resources and the necessary facilities, our findings urge for a prevalence study whose design takes into account the factors identified in the meta-regression analysis.
authors.affiliation: Department of Primary and Community Care (S.C.K., J.C.B., M.C.v.d.W.), Department of Internal Medicine (T.D., A.R.H., J.W.L., J.D.), Department for Health Evidence (H.J.G., G.J.v.d.W.), Radboud University Medical Center, Nijmegen, The Netherlands; Department of Internal Medicine III (J.W.L.), University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: Sabine C
authors.initials: SC
authors.lastname: Käyser
authors.affiliation: Department of Primary and Community Care (S.C.K., J.C.B., M.C.v.d.W.), Department of Internal Medicine (T.D., A.R.H., J.W.L., J.D.), Department for Health Evidence (H.J.G., G.J.v.d.W.), Radboud University Medical Center, Nijmegen, The Netherlands; Department of Internal Medicine III (J.W.L.), University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Dekkers
authors.affiliation: Department of Primary and Community Care (S.C.K., J.C.B., M.C.v.d.W.), Department of Internal Medicine (T.D., A.R.H., J.W.L., J.D.), Department for Health Evidence (H.J.G., G.J.v.d.W.), Radboud University Medical Center, Nijmegen, The Netherlands; Department of Internal Medicine III (J.W.L.), University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Groenewoud
authors.affiliation: Department of Primary and Community Care (S.C.K., J.C.B., M.C.v.d.W.), Department of Internal Medicine (T.D., A.R.H., J.W.L., J.D.), Department for Health Evidence (H.J.G., G.J.v.d.W.), Radboud University Medical Center, Nijmegen, The Netherlands; Department of Internal Medicine III (J.W.L.), University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: Gert Jan
authors.initials: GJ
authors.lastname: van der Wilt
authors.affiliation: Department of Primary and Community Care (S.C.K., J.C.B., M.C.v.d.W.), Department of Internal Medicine (T.D., A.R.H., J.W.L., J.D.), Department for Health Evidence (H.J.G., G.J.v.d.W.), Radboud University Medical Center, Nijmegen, The Netherlands; Department of Internal Medicine III (J.W.L.), University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Carel Bakx
authors.affiliation: Department of Primary and Community Care (S.C.K., J.C.B., M.C.v.d.W.), Department of Internal Medicine (T.D., A.R.H., J.W.L., J.D.), Department for Health Evidence (H.J.G., G.J.v.d.W.), Radboud University Medical Center, Nijmegen, The Netherlands; Department of Internal Medicine III (J.W.L.), University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: Mark C
authors.initials: MC
authors.lastname: van der Wel
authors.affiliation: Department of Primary and Community Care (S.C.K., J.C.B., M.C.v.d.W.), Department of Internal Medicine (T.D., A.R.H., J.W.L., J.D.), Department for Health Evidence (H.J.G., G.J.v.d.W.), Radboud University Medical Center, Nijmegen, The Netherlands; Department of Internal Medicine III (J.W.L.), University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: Ad R
authors.initials: AR
authors.lastname: Hermus
authors.affiliation: Department of Primary and Community Care (S.C.K., J.C.B., M.C.v.d.W.), Department of Internal Medicine (T.D., A.R.H., J.W.L., J.D.), Department for Health Evidence (H.J.G., G.J.v.d.W.), Radboud University Medical Center, Nijmegen, The Netherlands; Department of Internal Medicine III (J.W.L.), University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: Jacques W
authors.initials: JW
authors.lastname: Lenders
authors.affiliation: Department of Primary and Community Care (S.C.K., J.C.B., M.C.v.d.W.), Department of Internal Medicine (T.D., A.R.H., J.W.L., J.D.), Department for Health Evidence (H.J.G., G.J.v.d.W.), Radboud University Medical Center, Nijmegen, The Netherlands; Department of Internal Medicine III (J.W.L.), University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: Jaap
authors.initials: J
authors.lastname: Deinum
mesh_terms: D000328:Adult; D001315:Australia / Q000453:epidemiology; D015340:Epidemiologic Research Design; D006801:Humans; D006929:Hyperaldosteronism / Q000453:epidemiology* / Q000209:etiology; D015995:Prevalence; D012044:Regression Analysis; D012189:Retrospective Studies; D013223:Statistics as Topic / Q000379:methods