Assessing the concordance and accuracy between hospital discharge data, electronic health records, and register books for diagnosis of inpatient admissions of miscarriage: A retrospective linked data study

Background: Despite the high prevalence of miscarriage, there are few studies which assess the concordance of a diagnosis of miscarriage in routinely collected health databases. Objectives: To determine agreement and accuracy for the diagnosis of miscarriage between electronic health records (EHR), the Hospital Inpatient-Enquiry (HIPE) system, and hospital register books in Ireland. Methods: This is a retrospective study comparing agreement of diagnosis of miscarriage between three hospital data sources from January to June 2017. All inpatient admissions for miscarriage were reviewed from a single, tertiary maternity hospital in Ireland. Kappa, sensitivity, specificity, positive and negative predictive value were calculated. Results: In this retrospective concordance study, EHR records confirmed 96.2% diagnosis of miscarriage of HIPE records, and 95.1% of register books records. A total of 95 records were not recorded in the register books but were recorded in HIPE and EHR. This study found a considerable variability when comparing definitions of type of miscarriage (i.e., missed miscarriage, incomplete, and complete) between the three data sources. Conclusion: Although this study found a high concordance in inpatient admissions for miscarriage between EHR, HIPE, and register books, a considerable discrepancy was found when classifying miscarriage between the three data sources.