National health surveys that collect data on poisonings in the U.S. may underestimate poisoning incidence by 60 to 90 percent, according to recent research from the University of Illinois at Chicago.
Researchers analyzed hospital billing records, patient demographics, exposure information and outcome data for poisoning-related hospital visits in Illinois in 2010, as well as poisoning incidence data from four national health surveys.
Their analysis found 425,000 cases involving alcohol and illicit drugs in Illinois that accounted for the majority of poisoning-related hospital visits in 2010, the charges for which were nearly $8 billion. Roughly half of the patients were seen in outpatient emergency departments.
When the researchers compared the Illinois data to the national health surveys' results, they found a significant number of poisoning cases were missing from the surveys.
Lee Friedman, PhD, associate professor of environmental and occupational health sciences in the UIC School of Public Health and co-author of the study, offered a possible explanation for the surveys' underestimation.
"Definitions for poisoning used by these surveys often exclude exposure to alcohol, illicit drugs, and adverse effects from prescribed drugs," said Dr. Friedman. "The actual burden related to poisoning to hospitals and society is actually much higher than previously thought."
Highlighted below are additional findings from the study.
- In 2009, poisonings surpassed transportation-related deaths and gun-related deaths to become the leading cause of fatal injury in the U.S.
- In Illinois, the most common exposures were alcohol, drug dependence/abuse, cannabis and hallucinogens, opioid analgesics, cocaine and barbiturates, and benzodiazepine.
- Poisoning-related mortality rates for outpatients (0.78 percent) and inpatients (1.82 percent) were low, as were incidents of intentional self-harm.
- Substance abuse was the most common type of poisoning in Illinois, accounting for about $4 billion in hospital costs, which is more than half of hospital poisoning-related charges.
- In 44.4 percent of outpatient cases and 31.3 percent of inpatient cases, alcohol exposures were identified. Adverse effects from therapeutic agents accounted for 32 percent of poisoning cases.
- The average length of stay for patients admitted to Illinois hospitals for poisonings, the majority due to alcohol, was 5.5 days, totaling more than $7 billion in costs.
"It's important to reintegrate alcohol and therapeutic drug reactions into the definition of poisoning in order to get a more accurate picture of the magnitude and burden of poisoning," concluded Dr. Friedman.