Epidemiology Reports ISSN 2054-9911 | Volume 3 | Article 1 Research Open Access Performance of an administrative claims algorithm to estimate the incidence of pure red cell aplasia in chronic hepatitis C patients Scott C. Quinlan 1* , Jennifer C.L. Hawes 1 , Daniel Mines 2 , Shirin Ahmed 2 , Stephan Lanes 1 , Vinay Mehta 2 , Crystal N. Holick 1 , Nancy Santanello 2 and T. Christopher Mast 2 1 HealthCore, Inc., 800 Delaware Avenue, Fifth Floor, Wilmington, DE 19801, USA. 2 Department of Epidemiology, Merck Research Laboratories, 351 N. Sumneytown Pike, North Wales, PA 19454, USA. *Correspondence: squinlan@healthcore.com Abstract Background: We developed and validated an algorithm to evaluate pure red cell aplasia (PRCA) incidence in chronic hepatitis C (CHC) patients in a large observational database. Methods: We conducted a retrospective study using the HealthCore Integrated Research Database SM (HIRD) in which we identified CHC patients and followed them forward to identify PRCA occurrences. Possible PRCA cases were identified based on a medical claim for aplastic anemia (ICD-9-CM 284.8x or 284.9x) with a claim for bone marrow biopsy in the prior 30 days. Medical records were requested and reviewed by an Adjudication Committee (AC) to confirm PRCA case status. The positive predictive value (PPV) and 95% confidence interval (CI) for the PRCA algorithm were estimated based on adjudication results. Results: A total of 36,164 CHC patients were identified yielding 25 suspected PRCA cases. Medical records were obtained and reviewed for 17 cases. Of these 17 cases, none were confirmed as PRCA (PPV: 0.0%; 95% CI 0.0-19.5%). Estimated confirmed PRCA incidence was 0.0/1,000 person-years (95% CI 0.00-0.05/1,000 person-years). Conclusions: Automated case definitions for PRCA performed poorly in identifying PRCA in CHC patients, limiting our ability to estimate PRCA incidence. PRCA in CHC patients is rare and difficult to study using large automated databases. Keywords: Observational study, hepatitis C, chronic, red-cell aplasia, pure, incidence © 2015 Quinlan et al; licensee Herbert Publications Ltd. his is an Open Access article distributed under the terms of Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0). his permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Introduction Pure red cell aplasia (PRCA) is a rare hematological disorder characterized by severe anemia, reticulocytopenia, and al- most complete absence of erythroid precursor cells in the bone marrow. All other cell lineages are present and appear morphologically normal [1]. Pure red cell aplasia is an acquired anemia that may be primary or develop secondary to a variety of neoplastic, autoimmune, or infectious diseases [1]. There have been case reports of PRCA developing in patients undergoing treatment for chronic hepatitis C (CHC) [2-8]. Limited data are available on the population-based PRCA incidence in patients treated for CHC. One hospital-based survey conducted in France of 6,630 treated CHC patients over one year found that PRCA developed in two of 581 patients who received EPO concomitantly (3.4 cases per 1,000 patients) [9]. The two PRCA cases were based on physician reporting and were not otherwise verified but the investigators were confident in their validity because one of the drug manufacturers also reported two cases of PRCA in CHC treated patients during the same time period [9]. The rarity of PRCA has limited the ability to conduct epi- demiologic studies, as large cohorts of patients are needed to identify sufficient cases for examination. Administrative claims databases offer large populations and have recently CrossMark ← Click for updates