TABLE 1

Definition of Covariates

VariableDefinition
DepressionIn the 2 y before the birth of her first child, the mother had the following:
 ≥1 hospitalization with a diagnosis of depression (unipolar and bipolar; 296.2–296.3, 296.5, 300.4, 309, and 311; ICD-10-CA codes F31.3–F31.5, F32, F33, F341, F380, F381, F432, F438, and F530)
 ≥1 physician visit with a diagnosis for depression (ICD-9-CM codes 309, 311)20
AnxietyIn the 2 y before the birth of her first child, the mother had the following:
 ≥1 hospitalization with a diagnosis of an anxiety disorder (ICD-9-CM codes 300.0, 300.2, 300.3; ICD-10-CA codes F40, F41.0, F41.1, F41.3, F41.8, F41.9, F42, F431)
 ≥1 physician visit with a diagnosis of an anxiety disorder (ICD-9-CM code 300)20
Substance use disordersIn the 2 y before the birth of her first child, the mother had the following:
 ≥1 hospitalization with a diagnosis for alcohol or drug psychoses, alcohol or drug dependence, or nondependent abuse of drugs (ICD-9-CM codes 291, 292, 303, 304, 305; ICD-10-CA codes F10–F19, F55)
 ≥1 physician visit with a diagnosis for alcohol or drug psychoses, alcohol or drug dependence, or nondependent abuse of drugs (ICD-9-CM codes 291, 292, 303, 304, 305)21
ADHDIn the 2 y before the birth of her first child, the mother had the following:
 ≥1 hospitalization for ADHD (ICD-9-CM code 314; ICD-10-CA code F90)
 ≥1 physician visit with a diagnosis for ADHD (ICD-9-CM code 314)22
Suicide attemptIn the 2 y before the birth of her first child, the mother had ≥1 hospitalization with a diagnosis for suicide or self-inflicted injury (ICD-9-CM codes E950–E959).23
Received expectant parent servicesThe mother received expectant parent services from CPS during her pregnancy (yes or no)
Prenatal careThe R-GINDEX is a measure of the adequacy of prenatal care by a health care provider. Knowledge of 3 birth-related outcomes are required to calculate the R-GINDEX:
 The gestational age of the infant (date of pregnancy and birth)
 The trimester during which prenatal care began
 The total no. prenatal visits during pregnancy
There are 6 major categories of prenatal care outcomes identified for the index:
 Inadequate prenatal care use
 Intermediate prenatal care use
 Adequate prenatal care use
 Intensive prenatal care
 No care
 Missing information on prenatal care24
Cesarean deliveryDuring the birth hospitalization, the OBCSECT field indicates a cesarean delivery or ICD-9-CM procedure code 74.0, 74.1, 74.2, or 74.9 is present in the hospital discharge abstract (before March 31, 2004). After April 1, 2004, this is identified by CCI code 5MD60 in the hospital discharge abstract of the birth hospitalization.25
Length of hospitalization during birthContinuous measures calculated separately for infants delivered vaginally and by cesarean because of different stays expected for these groups26
Breastfeeding initiationExclusive or partial breastfeeding at hospital discharge26
Low birth wtIf child was born weighing <2500 g26
PrematureIf child was born at <37 wk gestation26
  • CCI, Canadian Classification of Health Interventions; ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification; ICD-10-CA, International Statistical Classification of Diseases and Related Health Problems, 10th Revision, Canada; OBCSECT, Hospital Abstract User Manual, Item 40 C.S. Type; R-GINDEX, Revised-Graduated Prenatal Care Utilization Index.