Feedback engagement strategies and metrics for consumers in vulnerable circumstances: An empty rapid review and recommendations for further research

Across sectors, there is an increasing recognition of the need to identify and support consumers in vulnerable situations. To assess whether existing support measures are effective and how they might be improved, satisfaction surveys are commonly used. However, low response rates and the under-representation of the most vulnerable groups are well-documented challenges threatening the representativeness, validity and consequently usefulness of survey data to understand their experiences. Moreover, it remains unclear whether these surveys effectively measure what they intend to. A rapid review of the peer-reviewed evidence was conducted to (i) identify barriers and explore strategies to increase participation in feedback mechanisms among consumers experiencing vulnerability within the energy, water, telecommunications and finance service sectors, and (ii) examine the availability and use of (validated) feedback or satisfaction measures for these groups. The review protocol was pre-registered on the Open Science Framework (https://osf.io/tqnvr). Searches were conducted in Web of Science and ProQuest Social Science databases in July 2025, and updated in August 2026, additionally including ProQuest ABI/INFORM Collection, ProQuest Sociology Collection, Scopus, Business Source Ultimate, EconLit and PsycINFO. No report met the inclusion criteria, highlighting a gap in the peer-reviewed empirical literature in the searched databases evaluating the effectiveness, validity and inclusiveness of feedback approaches for consumers in vulnerable circumstances. Consequently, there is insufficient evidence to determine whether existing and potential alternative approaches are adequate for these groups. The review concludes with recommendations for future research to design and evaluate accessible, valid, and representative approaches to collect feedback from consumers experiencing vulnerability.