title: Association between success rate and citation count of studies of radiofrequency catheter ablation for atrial fibrillation: possible evidence of citation bias.
abstract: BACKGROUND
  The preferential citation of studies with the highest success rates could exaggerate perceived effectiveness, particularly for treatments with widely varying published success rates such as radiofrequency catheter ablation for atrial fibrillation.
  
  
  RESULTS
  We systematically identified observational studies and clinical trials of radiofrequency catheter ablation of atrial fibrillation between 1990 and 2012. Generalized Poisson regression was used to estimate association between study success rate and total citation count, adjusting for sample size, journal impact factor, time since publication, study design, and whether first or last author was a consensus-defined pre-eminent expert. We identified 174 articles meeting our inclusion criteria (36 289 subjects). After adjustment only for time since publication, a 10-point increase above the mean in pooled reported success rates was associated with a 17.8% increase in citation count at 5 years postpublication (95% confidence interval, 7.1-28.4%; P<0.001). After additional adjustment for impact factor, sample size, randomized trial design, and pre-eminent expert authorship, the association remained significant (18.6% increase in citation count; 95% confidence interval, 7.6-29.6%; P<0.0001). In this full model, time since publication, impact factor, and pre-eminent expert authorship were significant covariates, whereas randomized control trial design and study sample size were not.
  
  
  CONCLUSIONS
  Among studies of radiofrequency catheter ablation of atrial fibrillation, high success rate was independently associated with citation count, which may indicate citation bias. To readers of the literature, radiofrequency catheter ablation of atrial fibrillation could be perceived to be more effective than the data supports. These findings may have implications for a wide variety of novel cardiovascular therapies.
authors.affiliation: From the Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (D.D.H., P.A.H., M.P.T.), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA; and Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (P.S., P.A.H., M.V.P., P.J.W., M.P.T.), and Department of Sleep Sciences and Medicine (T.H.H), Stanford University School of Medicine, Palo Alto, CA.
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Perino
authors.affiliation: From the Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (D.D.H., P.A.H., M.P.T.), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA; and Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (P.S., P.A.H., M.V.P., P.J.W., M.P.T.), and Department of Sleep Sciences and Medicine (T.H.H), Stanford University School of Medicine, Palo Alto, CA.
authors.forename: Donald D
authors.initials: DD
authors.lastname: Hoang
authors.affiliation: From the Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (D.D.H., P.A.H., M.P.T.), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA; and Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (P.S., P.A.H., M.V.P., P.J.W., M.P.T.), and Department of Sleep Sciences and Medicine (T.H.H), Stanford University School of Medicine, Palo Alto, CA.
authors.forename: Tyson H
authors.initials: TH
authors.lastname: Holmes
authors.affiliation: From the Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (D.D.H., P.A.H., M.P.T.), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA; and Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (P.S., P.A.H., M.V.P., P.J.W., M.P.T.), and Department of Sleep Sciences and Medicine (T.H.H), Stanford University School of Medicine, Palo Alto, CA.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Santangeli
authors.affiliation: From the Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (D.D.H., P.A.H., M.P.T.), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA; and Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (P.S., P.A.H., M.V.P., P.J.W., M.P.T.), and Department of Sleep Sciences and Medicine (T.H.H), Stanford University School of Medicine, Palo Alto, CA.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Heidenreich
authors.affiliation: From the Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (D.D.H., P.A.H., M.P.T.), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA; and Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (P.S., P.A.H., M.V.P., P.J.W., M.P.T.), and Department of Sleep Sciences and Medicine (T.H.H), Stanford University School of Medicine, Palo Alto, CA.
authors.forename: Marco V
authors.initials: MV
authors.lastname: Perez
authors.affiliation: From the Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (D.D.H., P.A.H., M.P.T.), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA; and Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (P.S., P.A.H., M.V.P., P.J.W., M.P.T.), and Department of Sleep Sciences and Medicine (T.H.H), Stanford University School of Medicine, Palo Alto, CA.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Wang
authors.affiliation: From the Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (D.D.H., P.A.H., M.P.T.), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA; and Department of Medicine (A.C.P.), Division of Cardiovascular Medicine, (P.S., P.A.H., M.V.P., P.J.W., M.P.T.), and Department of Sleep Sciences and Medicine (T.H.H), Stanford University School of Medicine, Palo Alto, CA. mintu@stanford.edu.
authors.forename: Mintu P
authors.initials: MP
authors.lastname: Turakhia
mesh_terms: D001281:Atrial Fibrillation / Q000453:epidemiology* / Q000628:therapy; D015982:Bias; D017115:Catheter Ablation; D002986:Clinical Trials as Topic; D005104:Expert Testimony; D006801:Humans; D019451:Information Management / Q000706:statistics & numerical data*; D055811:Journal Impact Factor; D011643:Publishing; D014481:United States
keywords: atrial fibrillation; bias (epidemiology); catheter ablation