{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T04:29:13Z","timestamp":1789532953641,"version":"build-2803163510"},"reference-count":43,"publisher":"Oxford University Press (OUP)","issue":"10","license":[{"start":{"date-parts":[[2025,1,14]],"date-time":"2025-01-14T00:00:00Z","timestamp":1736812800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/journals\/pages\/open_access\/funder_policies\/chorus\/standard_publication_model"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,10,7]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:p>The accuracy of low birth weight (LBW) and small for gestational age (SGA) in administrative health care records is crucial for perinatal studies but there are few published validity studies. Using 1999-2010 Medicaid Analytic eXtract (MAX) data linked to birth certificates (BCs), we identified mother-infant dyads (\u226530\u00a0days enrollment after delivery, with valid gestational age [GA] and birth weight [BW] data). We identified LBW and SGA according to International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Infants with BW &amp;lt;\u200910% of the US reference were flagged as SGA. For LBW group diagnoses, we imputed BW using median, mean BW from BCs, and ICD code boundaries of infants in the same LBW group. We calculated the sensitivity, specificity, and positive and negative predictive values to assess performance. We identified 1\u2009536\u2009272 live births. All LBW groups had low Ses and high SPs and NPVs, whereas PPVs varied. Among infants with SGA diagnoses based on GA\/BW from the BC, SE of the SGA codes was 13.36%, SP was 99.01%, and PPV was 67.37%. Combining imputation with LBW codes increased SE up to 22.09% (lower boundary) but decreased PPV to 41.53% (lower boundary). The ICD-9-CM codes from administrative health care records had low SE but high SP. Imputation based on GA and BW did not add much value to SGA identification.<\/jats:p>","DOI":"10.1093\/aje\/kwae472","type":"journal-article","created":{"date-parts":[[2025,1,15]],"date-time":"2025-01-15T22:26:06Z","timestamp":1736979966000},"page":"2887-2895","source":"Crossref","is-referenced-by-count":4,"title":["Validation of diagnosis codes for low birth weight and small for gestational age in the Medicaid Analytic eXtract database"],"prefix":"10.1093","volume":"194","author":[{"given":"Xi","family":"Wang","sequence":"first","affiliation":[{"name":"Department of Pharmaceutical Outcomes and Policy, College of Pharmacy, University of Florida , Gainesville, FL ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7040-1561","authenticated-orcid":false,"given":"Yehua","family":"Wang","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Outcomes and Policy, College of Pharmacy, University of Florida , Gainesville, FL ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6697-6450","authenticated-orcid":false,"given":"Yanmin","family":"Zhu","sequence":"additional","affiliation":[{"name":"Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women\u2019s Hospital and Harvard Medical School , Boston, MA ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Diana","family":"Montoya-Williams","sequence":"additional","affiliation":[{"name":"Division of Neonatology, The Children's Hospital of Philadelphia , Philadelphia, PA ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joshua","family":"Brown","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Outcomes and Policy, College of Pharmacy, University of Florida , Gainesville, FL ,","place":["United States"]},{"name":"Center for Drug Evaluation and Safety, University of Florida , Gainesville, FL ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amie J","family":"Goodin","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Outcomes and Policy, College of Pharmacy, University of Florida , Gainesville, FL ,","place":["United States"]},{"name":"Center for Drug Evaluation and Safety, University of Florida , Gainesville, FL ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ellen","family":"Zimmerman","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology, Hepatology & Nutrition, College of Medicine, University of Florida , Gainesville, FL ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Almut G","family":"Winterstein","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Outcomes and Policy, College of Pharmacy, University of Florida , Gainesville, FL ,","place":["United States"]},{"name":"Center for Drug Evaluation and Safety, University of Florida , Gainesville, FL ,","place":["United States"]},{"name":"Department of Epidemiology, Colleges of Medicine and Public Health and Health Professions, University of Florida , Gainesville, FL ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2025,1,14]]},"reference":[{"key":"2025101606073304000_ref1","doi-asserted-by":"publisher","first-page":"67","DOI":"10.4137\/CMPed.S40070","article-title":"Intrauterine growth restriction: antenatal and postnatal aspects","volume":"10","author":"Sharma","year":"2016","journal-title":"Clin Med Insights Pediatr."},{"issue":"2","key":"2025101606073304000_ref2","doi-asserted-by":"publisher","first-page":"219","DOI":"10.1210\/er.2006-0039","article-title":"Small for gestational age: short stature and beyond","volume":"28","author":"Saenger","year":"2007","journal-title":"Endocr Rev."},{"issue":"6","key":"2025101606073304000_ref3","doi-asserted-by":"publisher","first-page":"413","DOI":"10.1016\/j.annepidem.2010.11.012","article-title":"Prepregnancy body mass index, smoking during pregnancy, and infant birth weight","volume":"21","author":"La Merrill","year":"2011","journal-title":"Ann Epidemiol."},{"issue":"9888","key":"2025101606073304000_ref4","doi-asserted-by":"publisher","first-page":"273","DOI":"10.1016\/S0140-6736(13)60311-6","article-title":"Effect of fetal and child health on kidney development and long-term risk of hypertension and kidney disease","volume":"382","author":"Luyckx","year":"2013","journal-title":"Lancet."},{"issue":"2","key":"2025101606073304000_ref5","doi-asserted-by":"publisher","first-page":"41","DOI":"10.15585\/mmwr.mm6602a1","article-title":"Inpatient hospitalization costs associated with birth defects among persons of all ages - 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