Study Population, Outcomes, and Factors for the Study of Hospital Differences in Unexpected Newborn Complications (Florida, 2004–2013)

Study populationa
Inclusion criteria
  SingletonHD, BC
  Term (37–41 completed wk gestation)BC
  Birth wt ≥2500 gBC
 Exclusion criteria
  Congenital anomalies (ICD-9 diagnosis codes)HD
  Maternal drug use (ICD-9 diagnosis codes)HD
  Fetal and placental conditions (diagnosis codes): placenta previa affecting fetus or newborn, light for dates, fetal growth retardation, hemolytic disease, hydrops fetalisHD
Unexpected newborn complicationsa
  Neonatal deathBC
  Neonatal transfer to another hospitalHD, BC
  Apgar score ≤3 at 5 or 10 minBC
  Severe ICD-9 diagnosis and procedure codes: birth trauma, hypoxia asphyxia, shock and resuscitation, respiratory (eg, continuous positive airway pressure use), infection (eg, severe sepsis), neurologic (eg, intraventricular hemorrhage)HD
  Sepsis and neonatal LOS >4 dHD, BC
  Moderate ICD-9 diagnoses and procedures: birth trauma, respiratory (eg, transient tachypnea of the newborn)HD
  Moderate ICD-9 diagnoses and procedures with neonatal LOS >4 d for cesarean delivery or neonatal LOS >2 d for vaginal delivery: birth trauma, respiratory, neurologic (eg, tomography of head), infectionHD, BC
  Long neonatal LOS: LOS >5 d without jaundice or social codeHD, BC
 Unexpected newborn complication subcategories
  Respiratory: severe and moderate ICD-9, moderate ICD-9 with LOS requirement as aboveHD, BC
  Infection: severe ICD-9 and moderate ICD-9 with LOS requirement as aboveHD, BC
  Transfer to higher level of care: used transfer to another hospital as proxyHD, BC
  Neurologic or birth injury: severe and moderate ICD-9, moderate ICD-9 with LOS requirement as aboveHD, BC
  Shock and resuscitation: severe ICD-9HD
  Long neonatal LOS (unspecified): long LOS as aboveHD, BC
Individual socioeconomic factors
 Maternal age, y: <20, 20–29, 30–39, ≥40BC
 Maternal race and ethnicity: NH white, NH black, Mexican, Puerto Rican, Cuban, Central or South American, otherBC
 Hispanic, Haitian, other NH
 Nativity: Florida born, US born non-Florida, foreign bornBC
 Marital status: married, not marriedBC
 Father acknowledgment: father’s age reported on birth certificate
 Maternal education: less than high school, high school or GED, some college (no degree), college graduateBC
 Insurance status: Medicaid, private, self-pay, otherHD
Individual medical risk factors
 Birth order and reproductive history: first, second, or third without previous cesarean, second or third with previous cesarean, fourth or later without previous cesarean, fourth or later with previous cesareanHD, BC
 Prepregnancy BMI: underweight (<18.5), normal (18.5–24.9), overweight (25–29.9), obese I (30–34.9), obese II (35–39.9), obese III (≥40)BC
 Maternal tobacco use during pregnancy: yes, noHD, BC
Individual-level health service factors
 Adequacy of prenatal care (GINDEX): intensive/adequate, intermediate, inadequate, no careBC
 Timing and reason for delivery initiationbHD, BC
  Spontaneous labor at 37–38 wk: vaginal birth without a record of induction (hospital discharge or birth certificate), cesarean without a record of induction but with either trial of labor or labor augmentation (birth certificate)
  Medically indicated induction or cesarean at 37–38 wkb
  NMI induction at 37–38 wk
  NMI cesarean without labor at 37–38 wk: cesarean without labor induction (hospital discharge or birth certificate), without trial of labor or augmentation reported (birth certificate), and without a medical indication for early delivery
  Delivery at ≥39 wk with medical indication for early deliveryb
  Delivery at ≥39 wk without medical indication for early delivery
  Delivery day of week: weekday (Monday–Friday), weekend (Saturday–Sunday)BC
Hospital-level health service factors
 Hospital level of NICU (I–III) and hospital annual birth volume (quartiles by level of NICU)AHCA, BC
 Hospital percentage of Medicaid births (quartiles by year)HD
 Hospital percentage of certified nurse midwife births (quartiles by year)BC
 Hospital rural or urban location (NCHS): large central metro; large fringe metro; medium metro; small, micro, nonmetroBC
 Hospital ownership: not-for-profit, investor owned, local government ownedAHCA
 Hospital geographic location, based on ACOG District XII (Florida) map: Northwestern (Section 1: Panhandle)BC
 Northeastern (Section 2: Northern), Central (Section 3), Western (Section 4), Eastern (Section 5), Southern (Section 6: Peninsula)c
 Hospital percentage of inductions: quartiles by yearHD, BC
 Hospital percentage of cesarean deliveries: quartiles by yearHD, BC
 Hospital percentage of nulliparous, term, singleton, vertex cesarean deliveries (quartiles by year)HD, BC
 Hospital obstetric and pediatric residency programsACGME
Year of delivery: 2004–2013BC
  • ACGME, Accreditation Council for Graduate Medical Education; ACOG, American Congress of Obstetricians and Gynecologists; BC, birth certificate; GINDEX, Graduated Index of Prenatal Care Utilization; HD, hospital discharge; ICD-9, International Classification of Diseases, Ninth Revision; NCHS, National Center for Health Statistics; NH, non-Hispanic.

  • a Study population inclusion and exclusion criteria and study outcomes are standard definitions for the unexpected newborn complications measure, as proposed by the CMQCC (

  • b List of medical indications provided in Supplemental Table 5, The Joint Commission’s List of Conditions Possibly Justifying Elective Delivery, v2015A1. Adapted from Table 11.07, available at:

  • c ACOG District XII (Florida) map available at: