Barbiturates present:Prid:Pt:Ser/Plas:Nom:Screen
barbiturates present:prid:pt:ser/plas:nom:screen
Barbiturates present:Presence or Identity:To identify measures at a point in time:Serum/Plasma:Nominal:Screen
barbiturates present:presence or identity:to identify measures at a point in time:serum/plasma:nominal:screen