

2. Department of Epidemiology, UMDNJ-School Public Health, New Jersey, USA.
3. Department of Maternal-Fetal Medicine, Kaiser Permanente West Los Angeles Medical Center, USA.
Background: To determine the extent to which the accuracy of reporting maternal and fetal clinical diagnoses and procedural coding varies between clinical utilization and perinatal services records.
Methods: Information on perinatal outcomes was extracted from Kaiser Permanente Southern California (KPSC) health plan perinatal service system (PSS) and clinical utilization records. A random sample of 400 charts was selected from eligible medical records. Clinical codes were abstracted for two time periods: 1/1/2003 through 12/31/2004 (paper medical records) and 1/1/2008 through 12/31/2008 (electronic medical records [EMRs]). Abstracted clinical codes were compared with corresponding diagnosis and procedural records, both maternal and fetal. Differences in coding accuracy between time periods were assessed through comparisons of sensitivity, specificity, positive and negative predictive value.
Results: The accuracy of clinical diagnoses and procedural coding varies considerably by outcome. Sensitivities were generally higher with clinical utilization than PSS records for placental abruption (97%), placenta previa (100%), preeclampsia (94%), gestational anemia (91%), PROM (83%), chorioamnionitis (97%), intrauterine growth restriction (80%), fetal distress (91%), malpresentation of the fetus (92%), incompetent cervix (73%), vaginal birth after cesarean delivery (75%), chronic hypertension (98%), and respiratory conditions (51%). Specificities and predictive values were acceptable for the majority of conditions.
Conclusion: Our findings suggest that many perinatal outcomes are not reliably coded in the PSS records. Accuracy of perinatal outcome identification can be improved by supplementing PSS records with electronic diagnosis and procedural codes from clinical utilization. Completeness of collected medical and obstetrical outcomes improved slightly after implementation of the EMR system at KPSC.
Keywords: Clinical coding, hospitalization, perinatal coding, PSS, pregnancy, sensitivity, specificity, predictive values