Survey of admission toxicology panels in patients with multiple hospitalizations.

Of 1309 different patients with toxicology panels performed on admission to our university medical center during 1978-79, 65 (5.0%) had more than one hospitalization or emergency-room visit. The average patient with multiple admission panels performed during the year was an alert 32-year-old man who presented to the emergency room a mean of 2.2 times, following an episode of suspected drug abuse. The visits were separated by a mean time interval of 2.5 months. An average 1.7 different drugs per patient were found on the admission toxicology screening (usually ethanol, a barbiturate, an opiate, or a phenothiazine). One third of the drugs per patient were positive again on subsequent hospitalizations of the patient. In more than a third of the instances in which repeated drugs were quantitated, the "repeat level" on the subsequent admission was within +/- 17% of that found on the first admission. Laboratory recognition of patients with repetitive admission toxicology screening may facilitate analysis by permitting specific-drug-oriented searches.