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. Patient and public involvement (PPI) in health research refers to researchers working together with patients and other members of the public on any or all aspects of a research study. For our study, we looked at how often patients and members of the public were involved in health research over time. We did this by reviewing original research publications of all study design types published in 10 general medical journals over 25 years, from 2000 to 2024. We searched a large online library of medical research articles to identify a random sample of 1,000 individual studies, with 4 articles per journal per year selected from 10 major general medical journals (5 adult and 5 pediatric) over the 25 year-period. Four reviewers classified trials as PPI + or PPI- and collected data on variables of interest. We found that 10% (97/1000) of published articles (13% in adult journals and 7% in pediatric journals) reported PPI across all types of health research over 25 years. Reporting of PPI increased over time from 0% in 2000 to 38% in 2024, an average increase of 15% per year. An increase in reporting of PPI was shown in adult journals (on average, 22% per year) but not in pediatric journals.