Primary care antibiotic prescribing in the elderly in Ireland

Published in Pharmacoepidemiology and Drug Safety, Volume 20 (6).
Introduction:
Infections are a major cause of mortality in the elderly population.1 They demand particular care in diagnosis and treatment. In the general population, antibiotics are widely believed to be overused and misused, with 80% of prescribing taking place in primary care by general practitioners (GPs).2 This practice contributes to antimicrobial resistance and incurs a substantial cost to the health care system. The majority of antibiotics are prescribed for respiratory illnesses which are of viral aetiology. These illnesses are usually self-limiting in otherwise healthy young adults (< 65 years) but are associated with increased mortality risk with increasing age.3 The aim of this study was to gather information on GP antibiotic prescribing in the elderly and compare it to the younger population in the Republic of Ireland.

Method:
Participating GPs gathered data on all antibiotics prescribed by them and the diagnosis being treated during 100 consecutive consultations. Ethical approval was granted by the local ethics committee.

Results:
Overall, 170 GPs nationally have completed the study which has resulted in data from 16 677 consultations. Almost a quarter (23.5%) of consultations were elderly patients (≥ 65 years, n = 3912). The median age was 75 years (IQR 70–80). Antibiotics were prescribed at 621 (15.9%) of these consultations. Urinary tract infections resulted in the most antibiotic prescriptions at 13.1% (81) consultations. Elderly patients (≥ 65 years) were less likely to receive an antibiotic prescription than younger patients, who received 2759 antibiotic prescriptions (21.5% of consultations, OR 0.69, 95%CI 0.63–0.76). The average age-specific antibiotic rate for patients 65 years and over was 14.92 per 100 consultations, while the rate was 20.21 for patients under 65 years. The majority of consultations for respiratory symptoms were by patients under 65 years and were twice more likely to consult than elderly patients (OR 2.08, 95%CI 1.87–2.23).

Conclusion:
These results demonstrate that the elderly receive fewer antibiotics even though they are higher consumers of medical care and more evidence supports their use than in the general population. The results suggest that potential inappropriate antibiotic prescribing is occurring in the younger population. Education initiatives are required to increase public awareness that not every respiratory infection requires an antibiotic.

References
Gavazzi G, Krause KH. Ageing and infection. Lancet Infectious Diseases 2002; 2: 657–664.
National Disease Surveillance Centre. S.A.R.I. A strategy for the control of antimicrobial resistance in Ireland, 2001; Dublin.
Treanor J and Falsey A. Respiratory viral infections in the elderly. Antiviral Research 1999; 44(2): 79–102.