Objectives To determine the impact of advice provided by Medicines Information services in National Health Service hospitals across England, Scotland and Wales, on patient care and clinical outcomes, and medicines safety.

Methods All healthcare professionals seeking advice on specific patients from participating Medicines Information services were invited to complete an online questionnaire to determine the impact of that advice on their patients. A multidisciplinary expert panel of healthcare professionals independently assessed the impact of advice for a sample of enquiries using an impact rating scale.

Results A total of 647 pharmacists, doctors and nurses sought advice from 62 Medicines Information services and completed questionnaires. Most (81%) needed Medicines Information advice before proceeding with their patients’ treatments, 99% used the advice in managing their patients, resulting in 92% (597/647) reporting a positive impact: a positive impact on patient care or outcome was reported for 85% of patients (547/647), a positive impact on medicines safety was reported for 77% of patients (499/647) and 15% of patients avoided a major risk (96/647). Agreement between enquirers and expert panel on impact was substantial for patient care and outcome (κ=0.62; p=0.001) and fair for medicines safety (κ=0.40; p=0.043). In 22% of cases (145/647), Medicines Information identified and advised on medicines issues that enquirers had not identified themselves which was associated with a positive impact on patients (p<0.01).

Conclusions Clinical advice from Medicines Information services across the UK to healthcare professionals had high levels of positive impact on patient care, outcomes and medicines safety.