A review of calls received by the UK National Poisons Information Service involving medical errors in hospitals, care homes and GP surgeries from April 2007 to March 2008

Objective: To investigate medical errors occurring in hospitals, GP surgeries and care homes over a twelve month period using call data from the National Poisons Information Service (NPIS). Methods: Records of all telephone enquiries received by the NPIS between 1 April 2007 and 31 March 2008 were reviewed. Enquiries involving medical errors in a hospital, GP surgery or care home were examined and details of the nature of error noted. Results: The NPIS received a total of 52,386 calls, of these 6946 (13.3%) related to medical errors. The majority of these (89%) occurred in the home, mainly patients taking extra doses of medication or confusing their medication with that of another's. A significant number of calls related to cases of medication error occurring in hospitals (301), GP surgeries (77) and care homes (263), where medicines are typically administered by a carer or healthcare professional. In hospitals, 203 cases (67.4%) involved an excess of medication. Of these 17.2% were due to the shifting of a decimal point, leading to a ten-fold increase in medication; 15.7% the doubling of prescribed dose; 6.9% weekly or monthly medication given daily; and 5.9% an increased infusion rate of intravenous medication. The incorrect medication accounted for 35 cases (11.6%) of hospital errors, while medication being administered via the incorrect route 34 cases (11.3%). In GP surgeries, 58 cases (75.3%) related to errors in administration of vaccinations. Of these 43 calls (74.1%) concerned an excessive dose or extra dose and 14 (24.1%) the incorrect vaccine. Of calls about medical errors in nursing or care homes, most were regarding either the administration of an excess of medication (39.2%) or a patient being given someone else's medication (39.5%). Conclusion: Medical errors account for a small but significant number of enquiries to NPIS. The most common error was that of excess dosing, either due to miscalculating or misreading the prescribed dose. Less common was the administration of incorrect medication, usually another patient's. Errors should be avoided by improving documentation of patient notes, more thorough systems for checking medication, and writing prescriptions more clearly.