BACKGROUND:

While the number of risk minimisation studies requested by European regulators has increased, poor response rates, as low as < 5%, hinder validity and generalisability of effectiveness studies of additional risk minimisation measures (aRMM) that employ surveys. Hence, the usefulness of aRMM to promote the safe use of medications often remains uncertain.

Low-dose analgesic methoxyflurane self-administered using a hand-held Penthrox® Inhaler was approved in Europe for emergency relief of moderate to severe pain in conscious adult patients with trauma in 2015 under supervision by ambulance or emergency department (ED) staff. The effectiveness of aRMM consisting of an healthcare professional (HCP) guide and checklist and a patient alert card (PAC) imposed by the regulatory authority was assessed by surveys of HCPs and patients.

OBJECTIVES:

To evaluate risk minimisation measures embedded in a comparative prospective post-authorisation safety study (PASS) to improve response rates.

METHODS:

Cross-sectional surveys were conducted of HCPs and patients in ED concurrently involved in a prospective comparative observational study six months after launch of methoxyflurane. The self-completed questionnaires were completed electronically by HCPs, and on paper during the patient´s stay in the ED. Receipt, knowledge and behaviour were assessed. The study aimed to recruit 250 HCPs and 250 patients to achieve a precision of ±5% for 80% of correct responses.

RESULTS:

Ten participating ED departments in the UK took part in both the HCP and patient survey.The response rate for the HCP survey was 79.9% (262 of 328 invited HCPs).The response rate for the patient survey was 59.7% (268 of 449 invited patients).

CONCLUSIONS:

The two surveys embedded within a prospective study produced much higher response rates than found in most surveys evaluating aRMM. Linking surveys with prospective PASS studies may improve response rates and obtain more valid results.