Incidence and outcomes of reported poisoning in the elderly

Abstract

Both inadvertent and intentional poisonings are responsible for increased morbidity and mortality in the elderly. This investigation estimates the incidence and describes the basic epidemiology of drug-related poisonings among community-dwelling elderly in the United States. The American Association of Poison Control Center's database and the National Medical Expenditure Survey, respectively, were used to calculate numerator and denominator data necessary to estimate incidence. There were approximately 135,000 calls to poison control centers from those 60 years of age and over between 1986 and 1990. For each study year, incidence estimates were adjusted for changes in prescribing based on data from the National Disease and Therapeutic Index.;Household and cosmetic products account for 30 percent of all calls regarding non-drug poisonings and topical medications accounted for more than 7,600 calls to poison control centers across the country. Approximately 90 percent of topical drug poisonings were via ingestion and seven people died. The majority of calls regarding non-drug and drug poisonings were from females.;More detailed analyses for antidepressants and benzodiazepines were performed to test hypotheses and develop a model predictive of the risk of adverse outcomes. Statistically significant differences in outcome were found among benzodiazepines and antidepressants after controlling for age, sex and census region. Outcome is coded as no effect, minor, moderate, major and death. Logistic regression analyses models were used to predict poisoning outcome, the dependent variable, with the remaining independent variables in the dataset. The variable admission to a health care facility was seen as a proxy measure for outcome and warranted a separate analysis. Several variables in each analysis are significant; confidence intervals were calculated to determine the effect size. For example, the odds ratios indicate that the estimate of relative risk of admission to a health care facility for antidepressants is related to an intentional poisoning, being symptomatic, living in the Mid-Atlantic census division, an adverse drug reaction (at normal doses or normal use) and the number of substances ingested. Thus, the study provides health care workers with an increased knowledge of drug misuse in the elderly and the adverse consequences of such use.