Trends in patient and public involvement in health research 2000-2024

Public involvement in health research has been defined as research carried out 'with' or 'by' members of the public, rather than 'to', 'about', or 'for' them. We examined trends in patient and public involvement (PPI) prevalence in health research based on reporting in original research articles published in ten general medical journals over 25 years (2000-2024).

For this bibliometric analysis, OVID Medline from 1 January 2000 to 31 December 2024 was used to identify a random sample of 1,000 individual studies, with 4 articles per journal per year selected from 10 general medical journals (5 adult and 5 pediatric) published over the 25 year-period. All study designs were included. We defined adult studies as those with participants 19 years or older and pediatric studies as those with participants 18 years or younger. Four reviewers independently classified studies as PPI + or PPI- and extracted data on primary study characteristics and on PPI methods for PPI+ studies. Log-linear regression was used to analyze trends over time.

Of 1000 articles, 97/1000 reported PPI (prevalence 10%, 95% CI: 8%-12%). PPI was more prevalent in adult than pediatric journals (13% vs. 7%; P = 0.002). Log-linear regression showed a significant increasing trend in reporting PPI over time (from 0% in 2000 to 38% in 2024) representing an average annual percentage change (APC) of 15.0% (95% CI: 9.6% - 20.6%). Percent PPI+ articles significantly increased over time in adult journals (APC, 22.2%; 95% CI: 16.5% - 28.2%) but not in pediatric journals (APC, 3.0%; 95% CI: -2.1% - 8.4%). By journal, The BMJ (journal with mandatory PPI reporting) had the highest PPI prevalence (24%). By country, PPI was most common in the United States (32%). PPI+ studies were more likely to be an experimental design, conducted in a community setting, and less likely to be multi-country, compared to PPI- studies.

Over 25 years, PPI reporting in original health research articles published in general medical journals increased on average, 15% per year. PPI reporting increased significantly in adult journals (on average, 22% per year) but not in pediatric journals. Level of PPI increased over time.

Not applicable.