---
data_dictionary: breast-feeding-preterm.csv

description: >
  This data comes from a research study done at Children's Mercy Hospital
  and St. Luke's Medical Center. This was a study of breast feeding in 
  pre-term infants. Infants were randomized into either a treatment group
  (NG tube) or a control group (Bottle). Infants in the NG tube group 
  were fed in the hospital via their nasogastral tube when the mother
  was not available for breast feeding. Infants in the bottle group
  received bottles when the mothers were not available. Both groups
  were monitored for six months after discharge from the hospital.

copyright:
  This data is in the public domain and is freely avaiable for anyone
  to use. Acknowledgement of the source is appreicated but not required.

format:
  comma-delimited
  
varnames: 
  first row of data
  
size:
  rows: 84
  columns: 28

vars:
  feed_typ:
    scale: categorical
    values:
      - Control
      - Treatment

  age_stop:
    label: Age at which infant stopped breast feeding
    scale: ratio
    range: non-negative real
    unit: weeks
    values:
      missing: -1

  sepsis:
    label: Diagnosis of sepsis
    scale: categorical
    values:
      - No
      - Yes

  total_ab:
    label: Total number of apnea and bradycardia incidents
    scale: ratio
    range: non-negative integer

  del_type:
    label: Type of delivery 
    scale: nominal
    values:
      1: Vaginal
      2: C-section
 
  mom_age:
    label: Mother's age
    scale: ratio
    range: positive integer
    unit: years

  gravida:
    label: Gravidity or number of pregnancies
    scale: ratio
    range: non-negative integer

  para:
    label: Parity or number of live births
    scale: ratio
    range: non-negative integer
   
  mar_st:
    label: Marital status of mother
    scale: nominal
    values:
      1: Single
      2: Married
     
  race:
    label: Mother's race
    scale: nominal
    values:
      W: White
      B: Black
      
  smoker:
    label: Smoking by mother during pregnancy
    scale: nominal
    values:
      Yes: 1
      No: 2
      missing: -1

  mi_hosp:
    label: Distance from the mother's home to the hospital
    unit: miles
    scale: ratio
    range: non-negative integer
    values:
      missing: -1
   
  ng_tube:
    label: Time on the NG tube
    unit: days
    scale: ratio
    range: non-negative integer
    values:
      missing: -1
   
  tot_bott:
    label: Bottles of formula given while in the hospital
    scale: ratio
    range: non-negative integer

  bw:
    label: Birthweight
    unit: kg
    scale: ratio
    range: non-negative real
   
  gest_age:
    label: Estimated gestational age
    unit: weeks
    scale: ratio
    range: positive integer

  apgar1:
    label: Apgar score at one minute
    scale: ordinal
    range: 0 through 10

  apgar5:
    label: Apgar score at five minutes
    scale: ratio
    range: 0 through 10
   
  bf1_wt:
    label: Weight at first breast feeding
    unit: kg
    scale: ratio
    range: positive real
    values:
      missing: -1
   
  bf1_age:
    label: Age at first breast feeding
    unit: hours
    scale: ratio
    range: positive integer   
    values:
      missing: -1
   
  dc_wt:
    label: Weight at discharge
    unit: kg
    scale: ratio
    range: positive real
    values:
      missing: -1
   
  dc_age:
    label: Age at discharge
    unit: days
    scale: ratio
    range: positive integer
   
  dc3_wt:
    label: Weight three days after discharge
    unit: days
    scale: ratio
    range: positive real
    values:
      missing: -1
   
  bf0:
    label: Breastfeeding status at hospital discharge
    scale: ordinal
    values:
      Exclusive: 1
      Partial: 2
      None: 4
   
  bf1:
    label: Breastfeeding status three days after discharge
    scale: ordinal
    values:
      Exclusive: 1
      Partial: 2
      None: 4
   
  bf2:
    label: Breastfeeding status six weeks after discharge
    scale: ordinal
    values:
      Exclusive: 1
      Partial: 2
      None: 4
      missing: -1
   
  bf3:
    label: Breastfeeding status three months after discharge
    scale: ordinal
    values:
      Exclusive: 1
      Partial: 2
      None: 4
      missing: -1
   
  bf4:
    label: Breastfeeding status six months after discharge
    scale: ordinal
    values:
      Exclusive: 1
      Partial: 2
      None: 4
      missing: -1