Effectiveness of Clinical Decision Support Systems on Prescribing Quality at a University Hospital in Enugu, South East Nigeria

Background: Clinical decision support systems (CDSS) embedded within electronic prescribing platforms have demonstrated improvements in prescribing quality and patient safety in high-income settings. Their effectiveness in resource-limited Nigerian hospital contexts, where technology adoption is recent and infrastructure is variable, remains understudied. This study evaluated the effect of a CDSS on prescribing quality at Enugu State University Teaching Hospital. Methods: A pre-post interrupted time series study design was used. Prescribing quality was assessed over 12 months pre-CDSS implementation and 12 months post-implementation across three clinical departments (medicine, paediatrics, surgery). Outcome measures included drug interaction alerts triggered, dosing error rate, allergy override frequency, and overall prescribing appropriateness score. Results: CDSS implementation was associated with a 34 percent reduction in clinically significant drug interaction prescribing errors and a 29 percent reduction in dosing errors. Allergy alerts were overridden in 42 percent of cases, with override justification documented in only 26 percent. Prescribing appropriateness scores improved significantly from 61 percent to 77 percent (p less than 0.001). Conclusion: CDSS significantly improved prescribing quality at this South East Nigerian teaching hospital. Alert override behaviour requires monitoring to maximise system benefit, and clinician education on alert management is essential. Keywords: clinical decision support, prescribing quality, medication safety, Enugu, electronic prescribing