The prevalence of prescribing errors in acute hospital admissions in older patients in a Dublin tertiary hospital.

Background: It is estimated that prescribing errors account for 7% of all medication errors, with up to 50% of hospital admissions at risk of a prescribing error. [1] In the Irish hospital setting, prescribing errors account for up to 50% of medication errors. [2] Older patients are more likely to be affected by prescribing errors due to polypharmacy and the potential for drug interactions.

Methods: We wished to estimate the prevalence of prescribing errors (as defined by Deanet al) [3] in patients aged 65 years and above who were admitted acutely(<2 weeks) to a Dublin tertiary hospital. The drug charts of medical and surgical patients (elective and non-elective) on all wards (excluding the neurosurgical and oncology wards)were reviewed by two clinical pharmacists over a two week period in April, excluding weekends. Fluid prescriptions and once only prescriptions were included, and intensive care prescriptions and blood product prescriptions were excluded from the study.

Results: There were 644 admissions in patients 65 and older during the study period and of these 106 (16%) were sampled for drug chart review (50% M: 50%F: mean age 78 +/-7.75). The total number of prescriptions reviewed was 1938and the mean number of medications prescribed per patient was 18 +/- 9.68. Of the 106 drug charts, 92% contained at least one prescribing error. Of the 1938 prescriptions, 25% contained at least one prescribing error. There were 501 prescribingerrors identifiedin total, and 46% of these related to legibility. The remaining 54% consisted of incorrect drug dose (15%), drug omissions (14%), incorrect drug frequency (5%), duplication of a drug or drug class (4%), omission of prescriber signature (3%)and inappropriate drug dose for renal function (2%). Regarding the timing of the prescribing errors, 72% occurred on admission. In relation to where the error originated,87%originated in the prescription writing process, while 11% originated in the prescribing decision. Drug allergy status was not documented on 14% of drug charts and73% (1416/1938) of prescriptions contained an illegible prescriber signature.

Conclusion: Our study has highlighted that prescribing errors remain a common patient safety issue in the acute hospital setting. While legibility errors may be improved with the introduction of computerised prescribing into the hospital setting, it is of concern that a significant number of the prescribing errors which we identified were related to prescriber knowledge and drug selection. It is important that these knowledge related errors are addressed with education initiatives, with an emphasis on legible prescriber signatures to improve patient safety.

References:

1. Lewis PJ, Dornan T, Taylor D, Tully MP, Wass V, Ashcroft DM. Prevalence, incidence and nature of prescribing errors in hospital inpatients: a systematic review. Drug Saf. 2009; 32(5): 379-89.

2. C Kirke, T Delaney, P O’Brien, K Robinson, G Creaton, E Relihan, N O’Hanlon, E Conyard, G Colohan, M Ni Shuilleabhain. Medication Safety in Hospitals Ir Med J. 2009 Nov-Dec;102(10):339-41 Drug Saf. 2005; 28(10): 891-900

3. Dean B, Barber N, Schachter M. What is a prescribing error? Qual Health Care. 2000 Dec; 9 (4): 232-7.