Eman S Haidari1,2, Henry C Lee2, Jessica L Illuzzi3, Haiqun Lin4, Xiao Xu3. 1. Neonatal-Perinatal Medicine Fellowship Program, Maternal and Child Health Research Institute, and ehaidari@stanford.edu. 2. Department of Pediatrics, Stanford Medicine, Stanford University, Stanford, California; and. 3. Department of Obstetrics, Gynecology, and Reproductive Sciences, School of Medicine and. 4. Department of Biostatistics, School of Public Health, Yale University, New Haven, Connecticut.
Abstract
OBJECTIVES: Efforts to study potential overuse of NICU admissions and hospital variation in practice are often hindered by a lack of an appropriate data source. We examined the concordance of hospital-level NICU admission rates between birth certificate data and California Children's Services (CCS) data to inform the utility of birth certificate data in studying hospital variation in NICU admissions. METHODS: We analyzed birth certificate data from California in 2012 and hospital-specific summary data from CCS regarding NICU admissions. NICU admission rates were calculated for both data sets while using CCS data as the gold standard. The difference between birth certificate-based and CCS-based NICU admission rates was assessed by using the Wilcoxon signed rank test, and concordance between the 2 rates was evaluated by using Lin's concordance correlation coefficient and Kendall's W concordance coefficient. RESULTS: Among a total of 103 hospitals that were linked between the 2 data sets, birth certificate data generally underreported NICU admission rates compared with CCS data (median = 7.72% vs 11.51%; P < .001). However, in a subset of 35 hospitals where the difference in NICU admission rates between the 2 data sets was small, the birth certificate-based NICU admission rate showed good concordance with the rate from CCS data (Lin's concordance correlation coefficient = 0.91; 95% confidence interval: 0.84-0.95; Kendall's W concordance coefficient = 0.99; P < .001). Hospitals with good-concordance data did not differ from other hospitals in the institutional characteristics assessed. CONCLUSIONS: For a selected subset of hospitals, birth certificate data may offer a reasonable means to investigate hospital variation in NICU admissions.
OBJECTIVES: Efforts to study potential overuse of NICU admissions and hospital variation in practice are often hindered by a lack of an appropriate data source. We examined the concordance of hospital-level NICU admission rates between birth certificate data and California Children's Services (CCS) data to inform the utility of birth certificate data in studying hospital variation in NICU admissions. METHODS: We analyzed birth certificate data from California in 2012 and hospital-specific summary data from CCS regarding NICU admissions. NICU admission rates were calculated for both data sets while using CCS data as the gold standard. The difference between birth certificate-based and CCS-based NICU admission rates was assessed by using the Wilcoxon signed rank test, and concordance between the 2 rates was evaluated by using Lin's concordance correlation coefficient and Kendall's W concordance coefficient. RESULTS: Among a total of 103 hospitals that were linked between the 2 data sets, birth certificate data generally underreported NICU admission rates compared with CCS data (median = 7.72% vs 11.51%; P < .001). However, in a subset of 35 hospitals where the difference in NICU admission rates between the 2 data sets was small, the birth certificate-based NICU admission rate showed good concordance with the rate from CCS data (Lin's concordance correlation coefficient = 0.91; 95% confidence interval: 0.84-0.95; Kendall's W concordance coefficient = 0.99; P < .001). Hospitals with good-concordance data did not differ from other hospitals in the institutional characteristics assessed. CONCLUSIONS: For a selected subset of hospitals, birth certificate data may offer a reasonable means to investigate hospital variation in NICU admissions.