Objective: To ascertain preventable and non-preventable risk factors for adverse drug events (ADEs) in elderly inpatients at hospital admission.
Patients and methods: This was a prospective study of 2814 inpatients over 70 years of age who were consecutively admitted from November 1997 to December 1999 to a 60-bed geriatric unit of a French university hospital, and the 500 consecutive ADEs that were present at admission. All drugs administered during the month preceding hospitalisation, signs or symptoms of ADEs, and risk factors related to the drug prescription or patient’s diseases were considered: excess drug doses, potential drug-drug interactions (DDIs), interfering chronic disease and acute interfering disease.
Results: 66.7% of the ADEs were associated with cardiovascular, metabolic, renal or neuropsychological symptoms. The drugs involved were mainly cardiovascular (43.7%) and psychotropic (31.2%) drugs. One or more risk factors (mainly DDIs and/or interfering acute diseases) were recorded in 81.2% of ADEs. An interfering acute disorder (usually dehydration) was more frequent in ADEs resulting from drugs or drug combinations administered for 1 month or more (p < 0.05). 41.3% of risk factors were preventable (some DDIs, excess doses, interfering chronic diseases). One risk factor alone or the combination of all risk factors was preventable in 40.2% of ADEs.
Conclusions: This study suggests that many ADEs in the elderly may be decreased by removing all the preventable risk factors before a drug is prescribed (mainly DDIs and excess doses) and by reinforcing drug monitoring when an interfering acute disease occurs.
Brawn LA, Castleden CM. Adverse drug reactions: an overview of special consideration in the management of the elderly patient. Drug Saf 1990; 5: 421–35PubMedCrossRefGoogle Scholar
Bates DW, Cullen DJ, Laird N, et al. Incidence of adverse drug events and potential adverse drug events: implications for prevention. JAMA 1995; 274: 29–34PubMedCrossRefGoogle Scholar
Montamat SC, Cusock B. Overcoming problems with polypharmacy and drug misuse in the elderly. Clin Geriatr Med 1992; 8: 143–58PubMedGoogle Scholar
Moore N, Lecointre D, Noblet C, et al. Frequency and cost of serious adverse drug reactions in a department of general medicine. Br J Clin Pharmacol 1998; 45: 301–8PubMedCrossRefGoogle Scholar
Bates DW, Spell N, Cullen DJ, et al. The costs of adverse drug events in hospitalized patients. JAMA 1997; 277: 307–11PubMedCrossRefGoogle Scholar
Classen DC, Pestotnik SL, Evans RS, et al. Adverse drug events in hospitalized patients: excess length of stay, extra costs, and attributable mortality. JAMA 1997; 277: 301–6PubMedCrossRefGoogle Scholar
Lazarou J, Pomeranz BH, Corey PN. Incidence of adverse drug reactions in hospitalized patients: a meta-analysis of prospective studies. JAMA 1998; 279: 1200–5PubMedCrossRefGoogle Scholar
Beers MH, Ouslander JG. Risk factors in geriatric drug prescribing: a practical guide to avoiding problems. Drugs 1989; 37: 105–12PubMedCrossRefGoogle Scholar
Atkin PA, Veitch PC, Veitch EM, et al. The epidemiology of serious adverse drug reactions among the elderly. Drugs Aging 1999; 14(2): 141–52PubMedCrossRefGoogle Scholar
Beyth RJ, Shorr RI. Epidemiology of adverse drug reactions in the elderly by drug class. Drugs Aging 1999; 14(3): 231–9PubMedCrossRefGoogle Scholar
Hanlon JT, Weinberger M, Samsa GP, et al. A randomized, controlled trial of a clinical pharmacist intervention to improve in appropriate prescribing in elderly outpatients with polypharmacy. Am J Med 1996; 100: 428–37PubMedCrossRefGoogle Scholar
Thomas EJ, Brenan TA. Incidence and types of preventable adverse events in elderly patients: population based review of medical records. BMJ 2000; 320(7237): 741–4PubMedCrossRefGoogle Scholar
Doucet J, Chassagne P, Trivalle C, et al. Drug-drug interactions related to hospital admissions in older adults: a prospective study of 1000 patients. J Am Geriatr Soc 1996; 44: 944–8PubMedGoogle Scholar
Field TS, Gurwitz JH, Avorn J, et al. Risk factors for adverse drug events among nursing home residents. Arch Intern Med 2001; 161: 1629–34PubMedCrossRefGoogle Scholar
Gurwitz JH, Field TS, Avorn J, et al. Incidence and preventability of adverse drug events in nursing homes. Am J Med 2000; 109: 87–94PubMedCrossRefGoogle Scholar