Validity of Heart Failure Diagnoses in Administrative Databases: A Systematic Review and Meta-Analysis Natalie McCormick 1,2 , Diane Lacaille 2,3,4 , Vidula Bhole 2,5 , J. Antonio Avina-Zubieta 2,3,4 * 1 Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada, 2 Arthritis Research Centre of Canada, Richmond, British Columbia, Canada, 3 Division of Rheumatology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada, 4 Cardiovascular Committee of the Canadian Rheumatology Administrative Data Network, Richmond, British Columbia, Canada, 5 EpiSolutions Consultancy Services, Thane, India Abstract Objective: Heart failure (HF) is an important covariate and outcome in studies of elderly populations and cardiovascular disease cohorts, among others. Administrative data is increasingly being used for long-term clinical research in these populations. We aimed to conduct the first systematic review and meta-analysis of studies reporting on the validity of diagnostic codes for identifying HF in administrative data. Methods: MEDLINE and EMBASE were searched (inception to November 2010) for studies: (a) Using administrative data to identify HF; or (b) Evaluating the validity of HF codes in administrative data; and (c) Reporting validation statistics (sensitivity, specificity, positive predictive value [PPV], negative predictive value, or Kappa scores) for HF, or data sufficient for their calculation. Additional articles were located by hand search (up to February 2011) of original papers. Data were extracted by two independent reviewers; article quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. Using a random-effects model, pooled sensitivity and specificity values were produced, along with estimates of the positive (LR+) and negative (LR2) likelihood ratios, and diagnostic odds ratios (DOR = LR+/LR2) of HF codes. Results: Nineteen studies published from1999–2009 were included in the qualitative review. Specificity was $95% in all studies and PPV was $87% in the majority, but sensitivity was lower ($69% in $50% of studies). In a meta-analysis of the 11 studies reporting sensitivity and specificity values, the pooled sensitivity was 75.3% (95% CI: 74.7–75.9) and specificity was 96.8% (95% CI: 96.8–96.9). The pooled LR+ was 51.9 (20.5–131.6), the LR2 was 0.27 (0.20–0.37), and the DOR was 186.5 (96.8–359.2). Conclusions: While most HF diagnoses in administrative databases do correspond to true HF cases, about one-quarter of HF cases are not captured. The use of broader search parameters, along with laboratory and prescription medication data, may help identify more cases. Citation: McCormick N, Lacaille D, Bhole V, Avina-Zubieta JA (2014) Validity of Heart Failure Diagnoses in Administrative Databases: A Systematic Review and Meta-Analysis. PLoS ONE 9(8): e104519. doi:10.1371/journal.pone.0104519 Editor: Yiru Guo, University of Louisville, United States of America Received April 9, 2014; Accepted July 10, 2014; Published August 15, 2014 Copyright: ß 2014 McCormick et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability: The authors confirm that all data underlying the findings are fully available without restriction. All relevant data are within the paper and its Supporting Information files. Funding: This study was funded in part by the Canadian Arthritis Network (http://www.canradnetwork.ca). Natalie McCormick is supported by a Doctoral Research Award from the Canadian Institutes of Health Research. J. Antonio Avina-Zubieta held a salary award from the Canadian Arthritis Network and The Arthritis Society of Canada. He is currently the British Columbia Lupus Society Scholar and holds a Scholar Award from the Michael Smith Foundation for Health Research. Diane Lacaille holds the Mary Pack Chair in Arthritis Research from UBC and The Arthritis Society of Canada. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: Vidula Bhole is the sole proprietor of a consulting company, EpiSolutions Consultancy Services. There are no patents, products in development or marketed products to declare. This does not alter the authors’ adherence to all the PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors. * Email: azubieta@arthritisresearch.ca Introduction Heart failure (HF) is a chronic condition that affects about 26 million people worldwide [1] and imposes a tremendous burden on these individuals and their families. The typical 40 year-old faces a 20% lifetime risk of developing HF [2], and the incidence of HF amongst adults 65 years of age and older is approximately 12.5 per 1,000 person-years [3]. About half of new cases are expected to die within five years of diagnosis [2], and estimates of the annual economic burden of HF have recently exceeded $30 billion in the United States [2], and $108 billion worldwide [4]. The European Society of Cardiology describes HF as a disorder of cardiac structure or function where the heart is unable to deliver adequate levels of oxygen to the tissues [5]. Cases often have primary left systolic HF, which is characterized by ‘‘reduced contraction and emptying of the left ventricle’’ [5]. Still, many cases have left diastolic HF, in which ventricular compliance and filling are impaired [6] but the contractile function of the ventricle is preserved. HF has some ‘classic’ signs and symptoms, including ankle oedema, and exertional dyspnoea and fatigue [5,6]. However, HF is not considered to be a discrete condition but a ‘‘complex clinical syndrome’’ [6] that occurs in conjunction with PLOS ONE | www.plosone.org 1 August 2014 | Volume 9 | Issue 8 | e104519