(026) Effectiveness of additional risk minimisation measures: Improving response rates and validity in surveys

Publication Number: 364

Background: Poor response rates, as low as < 5%, has hindered the validity and generalisability of many effectiveness studies of additional risk minimisation measures (aRMM) that employ surveys requested by European regulators. Low-dose analgesic methoxyflurane (Penthrox®) was approved in Europe for relief of moderate to severe pain in conscious adults with trauma in 2015 in Emergency Department (ED). We designed a survey study to evaluate aRMM embedded in a comparative prospective post-authorisation safety study (PASS) to improve response rates.

Objectives: To evaluate the effectiveness of aRMM by measuring receipt of materials, knowledge, and impact on behavioural implementation of key safety information contained in the HCP administration guide and checklist, and in the patient alert card for methoxyflurane.

Methods: The aRMM consisted of a healthcare professional (HCP) guide and checklist and a patient alert card (PAC). Cross-sectional surveys were administered to HCPs and patients from the emergency setting six months after launch of methoxyflurane to assess the implementation of aRMM. Questionnaires were self-completed electronically by HCPs, and on paper by patients during their stay in the ED, recruited consecutively. 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. Finally, 262 of 328 invited HCPs and 268 of 449 invited patients were included for analysis.

Results: Among the HCPs who were aware of each aRMM, the checklist was received by 130 out of 174, while 185 out of 216 reported having received the PAC and 209 out of 238 the guide. The mean (SD) level of readability achieved by the checklist was 80.8% (18.48), while the PAC and guide scored 78.0% (18.5) and 77.3% (8.0), respectively. The overall mean (SD) level of knowledge was 73.3% (17.7) and the overall knowledge and proportion of correct responses on messages explicitly included in the aRMM is above 70%. Of the 262 HCPs, 93.0% reported normally providing the PAC to the patient.
Among the 82 patients who were aware of the PAC, 78 reported having had access to or had received the PAC. Of those who received the PAC, 65.4% (51/78) read it. Of those patients included (n=268), the overall mean (SD) score for knowledge was 21.3% (22.1) and the overall mean (SD) score for correct behaviour was 26.6% (34.1).

Conclusions: The two surveys embedded within a prospective study produced much higher response rates than found in most surveys evaluating aRMM. The results for effectiveness of methoxyflurane aRMM are given greater validity and generalizability by these high response rates. Linking surveys with prospective PASS studies should be encouraged to increase response rates.