Number of papers published in BMJ Open in 2020 by method used, and proportion of these with PPI
| Method | n | % of total | Mean % PPI (95% CI) |
| Mixed methods | 70 | 2.3 | 38.6 (27.1 to 50.1) |
| Implementation | 65 | 2.2 | 35.4 (23.7 to 47.1) |
| Trial | 551 | 18.4 | 34.8 (30.9 to 38.8) |
| Qualitative | 260 | 8.7 | 34.2 (28.4 to 40.0) |
| Evaluation | 115 | 3.8 | 33.0 (24.4 to 41.7) |
| Pilot study | 42 | 1.4 | 31.0 (16.8 to 45.1) |
| Development | 118 | 3.9 | 29.7 (21.3 to 37.9) |
| Protocol | 1181 | 39.3 | 28.9 (26.3 to 31.5) |
| Health economics | 91 | 3.0 | 25.3 (16.3 to 34.3) |
| Survey | 158 | 5.3 | 17.7 (11.7 to 23.7) |
| Observational | 220 | 7.3 | 15.9 (11.1 to 20.8) |
| Cohort | 637 | 21.2 | 14.6 (11.9 to 17.3) |
| Scoping | 125 | 4.2 | 13.6 (7.6 to 19.6) |
| Time series | 25 | 0.8 | 12.0 (−1.0 to 25.0) |
| Systematic review | 376 | 12.5 | 9.6 (6.6 to 12.6) |
| Cross-sectional | 464 | 15.5 | 9.3 (6.6 to 11.9) |
| Meta-analysis | 265 | 8.9 | 8.3 (5.0 to 11.6) |
| Simulation | 38 | 1.3 | 5.3 (−1.9 to 12.5) |
Note that total n and % of papers here each sum to more than the total number of papers or to >100% because some have more than one designation—for example, both protocol and trial.
PPI, patient and public involvement.