A systematic review of validated methods to capture stillbirth and spontaneous abortion using administrative or claims data

• Among 13 studies using algorithms to identify either outcome, none used the same combination of codes.
• Rates of stillbirth and spontaneous abortion identified ranged substantially.
• One study fully described validation procedures and statistics for stillbirth; none validated codes for spontaneous abortion.
• Data sets used may not be generalizable to the general population of pregnant women in the U.S.
• Additional validation studies with a nationally representative sample are needed.

PurposeTo identify and assess diagnosis, procedure and pharmacy dispensing codes used to identify stillbirths and spontaneous abortion in administrative and claims databases from the United States or Canada.MethodsWe searched the MEDLINE database from 1991 to September 2012 using controlled vocabulary and key terms related to stillbirth or spontaneous abortion. We also searched the reference lists of included studies. Two investigators independently assessed the full text of studies against pre-determined inclusion criteria. Two reviewers independently extracted data regarding participant and algorithm characteristics and assessed each study's methodological rigor using a pre-defined approach.ResultsTen publications addressing stillbirth and four addressing spontaneous abortion met our inclusion criteria. The International Classification of Diseases, Ninth Revision (ICD-9) codes most commonly used in algorithms for stillbirth were those for intrauterine death (656.4) and stillborn outcomes of delivery (V27.1, V27.3-V27.4, and V27.6-V27.7). Papers identifying spontaneous abortion used codes for missed abortion and spontaneous abortion: 632, 634.x, as well as V27.0–V27.7. Only two studies identifying stillbirth reported validation of algorithms. The overall positive predictive value of the algorithms was high (99%–100%), and one study reported an algorithm with 86% sensitivity. However, the predictive value of individual codes was not assessed and study populations were limited to specific geographic areas.ConclusionsAdditional validation studies with a nationally representative sample are needed to confirm the optimal algorithm to identify stillbirths or spontaneous abortion in administrative and claims databases.‘