Medication errors: how reliable are the severity ratings reported to the national reporting and learning system?

To examine: (1) the reliability of the severity rating scale used by the National Reporting and Learning System (NRLS) in England and Wales for medication errors; and (2) the likelihood of reporting medication errors among healthcare professionals.

A 900-bed acute university teaching hospital in the North West of England.

Forty healthcare professionals (10 doctors, 10 nurses, 10 pharmacists and 10 pharmacy technicians).

Participants were asked to complete a self-administered questionnaire containing nine medication error scenarios on two separate occasions. They were asked to rate the severity of each incident using the NRLS severity rating scale and also the likelihood of reporting the incident via the hospital incident reporting system. The

included comparisons of severity ratings and likelihood of reporting by the four health professional groups. Test-retest reliability of the severity ratings was also examined within and between professional groups.

Pharmacists and nurses were significantly more likely to report the errors if they had witnessed them (mean scores 36.3 and 36.2, respectively, compared with 27.9 for doctors, P < 0.001). Nurses and pharmacy technicians assigned higher severity ratings for medication errors (mean scores 23.6 and 25, respectively) than pharmacists or doctors (both 19.4). Both within and between healthcare professional groups, there was wide variation in the assignment of medication error severity ratings.

There are marked differences in the severity ratings for medication errors graded against the NRLS severity criteria between different health professional groups and at different time points rated by the same individuals.