To understand the incidence and types of medication prescribing errors in a low resource setting ophthalmology clinic and to determine the impact of a preprinted prescription based on the hospital formulary (FormularyScript) on medication prescribing errors.
Non-randomised interventional study.
Ophthalmology clinic in a teaching hospital in northeast Thailand.
4349 handwritten prescriptions collected from October 2009 to December 2009, and 4146 FormularyScripts collected from February 2010 to May 2010.
Primary and secondary outcome measures
All prescriptions from the handwritten and FormularyScript groups were analysed for medication error rates by types (legibility, ambiguous, incomplete, abbreviation and accuracy) and subtypes (drug name, strength, which eye, route and dispensed amount).
Comparison of error rates in the two groups showed a 10-fold reduction in the overall error rate using FormularyScript (32.9%–3.5%, p<0.001). FormularyScripts were associated with statistically significant (p<0.001) decreases in the following error types: legibility (16.1%–0.1%), incomplete (16.1%–0.1%) and abbreviation (3.1%–0.3%). There was no statistically significant change in accuracy errors (0.8%–0.6%, p=0.21). Ambiguous errors increased with FormularyScripts (0.6%–2.5%, p<0.001), likely due to the introduction of new ways to make errors. Decreases were seen in all legibility, abbreviation and accuracy error subtypes, and four out of six incomplete error subtypes. There were statistically significant increases in both ambiguous error subtypes: which eye (0.3%–2.5%, p<0.001) and drug name (0.3%–0.6%, p=0.03).
In our study population, outpatient medication prescribing errors were common and primarily due to legibility and incomplete error types. A preprinted prescription form has the potential to decrease medication prescribing errors related to legibility, incomplete prescribing information and use of unacceptable abbreviations without changing the overall rate of accuracy errors. However, new error types can occur.
Little is known about the frequency and types of medication prescribing errors in developing countries, especially outpatient settings.
Computerised prescribing systems are usually not feasible in low resource settings; however, a preprinted form may be an alternative.
Medication prescribing errors are common in outpatient ophthalmology clinics and are primarily due to legibility and incomplete information.
Preprinted prescription forms have the potential to decrease medication prescribing errors related to legibility, incomplete prescribing information and use of unacceptable abbreviations without changing the overall rate of accuracy errors, but new error types can be introduced.
Any new medication prescribing system needs to be carefully monitored for unintended consequences. Working closely with physicians and pharmacists to optimise design and providing adequate training for users are important considerations in minimising the introduction of new ways of making errors.
Strengths and limitations of this study
The main strengths of this study are that it demonstrates that a low cost alternative to computerised prescribing exists and is effective at reducing the most common types of medication prescribing errors.
Important limitations of this study are that it is a non-randomised study conducted at a single site, the subjective nature of determining and classifying error types such as legibility, the FormularyScript did not include all necessary medications and physicians were aware that the prescriptions were being analysed for prescribing errors.