Best practice implementation in gerontology and geriatrics delphi studies: a scoping review

With Delphi panels in aging research proliferating, we conducted a scoping review to: (1) aggregate key practice recommendations; (2) document their use in aging research; and (3) use findings to recommend practices and their reporting for aging researchers in the form of a Delphi Quality Criteria Rating Form for Aging (DQ4A).

We conducted a scoping review of Delphi studies focused on aging published in peer-reviewed journals using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Searches were run in May 2025 in relevant databases. Titles, abstracts, and full-texts screening yielding a sample of 102 articles. Data were extracted and synthesized to feature study characteristics and Delphi methodological practices. Results informed creation of the DQ4A.

Adherence to methodological recommendations varied, highlighting the need for streamlined guidance. Common practices included specification of panelist selection criteria (95%), provision of the final product (93%), and substantiation of Delphi method use (78%). Least represented practices included targeting number of panelists based on anticipated attrition (11%), use of double blinding (14%), and panelist review of original and modified products (18%). Using the DQ4A, we demonstrate that 24% of all studies had average quality, 33% had higher-than-average quality, and 43% had lower-than-average quality.

Findings highlight methodological gaps, indicating recommendations to improve the Delphi method in gerontology and geriatrics. Investigators can use the DQ4A to improve conduct and reporting of Delphi studies while ensuring that resultant products reflect diverse stakeholder needs.