Validation of administrative and clinical case definitions for gestational diabetes mellitus against laboratory results. Issue 6 (16th November 2016)

• Record Type: Journal Article
• Authors: Bowker, S. L.; Savu, A.; Donovan, L. E.; Johnson, J. A.; Kaul, P.
• Is Part Of: Diabetic medicine. Volume 34:Issue 6(2017)
• Page Start: 781
• Page End: 785
• Publication Date: 2016-11-16
• Subjects: Diabetes -- Periodicals; 616.462
• DOI: 10.1111/dme.13271
• Languages: English
• ISSNs: 0742-3071

Abstract

Abstract: Aim: To examine the validity of International Classification of Disease, version 10 (ICD‐10) codes for gestational diabetes mellitus in administrative databases (outpatient and inpatient), and in a clinical perinatal database (Alberta Perinatal Health Program), using laboratory data as the 'gold standard'. Methods: Women aged 12–54 years with in‐hospital, singleton deliveries between 1 October 2008 and 31 March 2010 in Alberta, Canada were included in the study. A gestational diabetes diagnosis was defined in the laboratory data as ≥2 abnormal values on a 75‐g oral glucose tolerance test or a 50‐g glucose screen ≥10.3 mmol/l. Results: Of 58 338 pregnancies, 2085 (3.6%) met gestational diabetes criteria based on laboratory data. The gestational diabetes rates in outpatient only, inpatient only, outpatient or inpatient combined, and Alberta Perinatal Health Program databases were 5.2% (3051), 4.8% (2791), 5.8% (3367) and 4.8% (2825), respectively. Although the outpatient or inpatient combined data achieved the highest sensitivity (92%) and specificity (97%), it was associated with a positive predictive value of only 57%. The majority of the false‐positives (78%), however, had one abnormal value on oral glucose tolerance test, corresponding to a diagnosis of impaired glucose tolerance in pregnancy. Conclusions: The ICD‐10 codes for gestational diabetes in administrative databases, especially when outpatient and inpatient databases are combined, can be used to reliably estimate the burden of the disease at the population level. Because impaired glucose tolerance in pregnancy and gestational diabetes may be managed similarly in clinical practice, impaired glucose tolerance in pregnancy is often coded as gestational diabetes. What's new?: This is the first study to examine the validity of International Classification of Disease, version 10 (ICD‐10) codes for gestational diabetes mellitus using laboratory data as the 'gold standard'. Gestational diabetes coding in outpatient and inpatient databases combined is highly sensitive (92%) and specific (97%) and can be used to estimate the burden of disease at the population level.