Subject: infant identifier
Wt: [ birth weight, kg ]
Apgar: [ 5-minute Apgar score, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]]
ApgarInd: [ Apgar class, [ < 5, '>= 5' ]]
time: [ time of event, h ]
event: [ type of event, [ dose, conc ]]
value:
 -
  - event == 'dose': dose of drug administered
  - event == 'conc': serum phenobarbital concentration
 -
  - event == 'dose': µg/kg
  - event == 'conc': µg/L
