Abstract and Introduction
Abstract
Objectives To determine types of potentially (PIMs) and actually inappropriate medications (AIMs), which PIMs are most likely to be considered AIMs, and risk factors for PIMs and AIMs at hospital discharge in elderly intensive care unit (ICU) survivors.
Design Prospective cohort study.
Setting Tertiary care, academic medical center.
Participants One hundred twenty individuals aged 60 and older who survived an ICU hospitalization.
Measurements Potentially inappropriate medications were defined according to published criteria; a multidisciplinary panel adjudicated AIMs. Medications from before admission, ward admission, ICU admission, ICU discharge, and hospital discharge were abstracted. Poisson regression was used to examine independent risk factors for hospital discharge PIMs and AIMs.
Results Of 250 PIMs prescribed at discharge, the most common were opioids (28%), anticholinergics (24%), antidepressants (12%), and drugs causing orthostasis (8%). The three most common AIMs were anticholinergics (37%), nonbenzodiazepine hypnotics (14%), and opioids (12%). Overall, 36% of discharge PIMs were classified as AIMs, but the percentage varied according to drug type. Whereas only 16% of opioids, 23% of antidepressants, and 10% of drugs causing orthostasis were classified as AIMs, 55% of anticholinergics, 71% of atypical antipyschotics, 67% of nonbenzodiazepine hypnotics and benzodiazepines, and 100% of muscle relaxants were deemed AIMs. The majority of PIMs and AIMs were first prescribed in the ICU. Preadmission PIMs, discharge to somewhere other than home, and discharge from a surgical service predicted number of discharge PIMs, but none of the factors predicted AIMs at discharge.
Conclusion Certain types of PIMs, which are commonly initiated in the ICU, are more frequently considered inappropriate upon clinical review. Efforts to reduce AIMs in elderly ICU survivors should target these specific classes of medications.
Introduction
Polypharmacy and inappropriate prescribing of medications are an increasing problem in elderly adults. Drug-related admissions for people aged 65 to 84 increased by 96% from 1997 to 2008,[1] and nearly half of adverse drug event–related hospitalizations occur in adults aged 80 and older.[2] Inappropriate medications in elderly adults can lead to confusion, falls, cognitive impairment, poor health status, and mortality.[3–7] The rapidly growing population of persons aged 65 and older[8] will only magnify these hazards unless more attention is focused on understanding and improving medication management and reconciliation.
In the lexicon of inappropriate prescribing, two important terms are potentially inappropriate medications (PIMs) and actually inappropriate medications (AIMs). PIMs are medications that—in light of their pharmacological effects and prior research—are deemed potentially harmful to an elderly adult; when a drug is labeled a PIM, no consideration is given to its potential benefits or the clinical circumstances surrounding its prescription for an individual, but a PIM can further be classified as an AIM if the risk of harm from the drug is judged to outweigh the potential clinical benefit after an individual's clinical circumstances are considered. Approximately 50% of hospitalized elderly adults are discharged on at least one PIM, and approximately 80% of these individuals are discharged on at least one AIM.[9–12]
Although PIMs and AIMs may be identified at the time of hospital discharge, the intensive care unit (ICU) is often where these medications are first prescribed. The fastest-growing group of individuals treated in the ICU is elderly adults,[13] a vulnerable population frequently given PIMs and AIMs in the hospital. It was recently found that 85% of elderly ICU survivors were discharged from the hospital on at least one PIM and that 51% were discharged on at least one AIM.[14] Of individuals with one or more PIMs at hospital discharge, 59% had at least one AIM.[14] Fifty-percent of PIMs and 59% of AIMs are first prescribed in the ICU.[14]
In this particularly complex population, many PIMs are reasonably appropriate given the individual's clinical conditions (the PIMs are not AIMs). Concordance or discordance of PIMs and AIMs has significant implications. For example, if drug class "A" accounts for a substantial proportion of PIMs in older ICU survivors, but the majority of these PIMs are appropriately prescribed given the individuals' circumstances, an intervention aimed at decreasing all PIMs will have the unintended consequence of reducing use of some appropriate medications. A more-focused approach is to reduce exposure to AIMs by addressing the location in the hospital where AIMs are most commonly initiated, targeting classes of PIMs that are most often judged to be actually inappropriate after consideration of individual's circumstances, and targeting individuals most likely to receive AIMs and providers most likely to prescribe them. The risk factors for prescription of AIMs in elderly adults surviving an ICU hospitalization are currently unknown.
This study extends previous work that described the prevalence of PIMs and AIMs in critically ill elderly adults[14] and explores which specific PIM categories at hospital discharge were most often considered AIMs, where specific AIM categories were most often initiated (before the hospital, a pre-ICU ward, ICU, or a post-ICU ward), and risk factors for PIMs and AIMs at hospital discharge. It was hypothesized that opiates, sedatives, and antipsychotics would be the PIMs that were most often AIMs in older ICU survivors and that older adults with delirium (which may prompt initiation of sedatives or antipsychotics) are at highest risk to be discharged from the hospital on PIMs and AIMs.
J Am Geriatr Soc. 2013;61(7):1128–1134 © 2013 Blackwell Publishing
