Table 2.
Trial and participant information leaflet characteristics
| Trial characteristics | Number of trials (n = 229) |
| Non-drug trialsa | 102 |
| Drug trialsa | 49 |
| Mixed trialsa | 71 |
| Vaccine trials | 2 |
| Unsure | 4 |
| No information | 1 |
| 2-arm trials | 191 |
| 3-arm trials | 21 |
| 4-arm trials | 6 |
| 5-arm trials | 3 |
| 6-arm trials | 1 |
| Otherb | 6 |
| Unclear | 1 |
| Commercialc | 41 |
| Non-commercial | 183 |
| No information | 5 |
| Trials involving vulnerable populations | 72 |
| Trials with multiple PILs | 22 |
| Disease area (defined by NIHR specialty area) | Number of trials |
| Cancer | 34 |
| Cardiovascular disease | 24 |
| Reproductive health | 22 |
| Gastroenterology | 19 |
| Kidney and urinary tract | 19 |
| Respiratory disorders | 11 |
| Children and young people | 8 |
| Dementias and neurodegeneration | 7 |
| Trauma and emergency care | 7 |
| Endocrinology | 7 |
| Mental health | 5 |
| Infectious diseases | 5 |
| Musculoskeletal disorders | 5 |
| COVID | 5 |
| Neurological disorder | 5 |
| Dermatology | 4 |
| Anaesthesia, perioperative medicine and pain management | 4 |
| Critical care | 3 |
| Oral and dental health | 3 |
| Surgery | 2 |
| Physiotherapy | 2 |
| Othere | 28 |
| PIL characteristics | Number of PILs (n = 280) |
| Mention of PPI involvement | 19 PILs |
| Graphics of any sort in the PILd | 96 PILs plus the video animation |
| PILs developed for children | 38 PILs |
| PILs developed for parents | 32 PILs |
| PILs developed for legal representatives | 9 PILs |
| PILs for develop for those that recover capacity | 14 PILs |
aDrug trials were classified as trials where both the intervention and comparator were drugs. Non-drug trials were classified as trials where both the intervention and comparator were non-drug. Mixed trials were classified as trials where the intervention or comparator were drug or non-drug
bThese trials included, for example depending on the severity of illness, different numbers of intervention options available to participants
cCommercial trials were classified as trials where there is funding from a commercial company or if there were links to commercial companies such as drug manufacturers that could potentially cause conflicts of interest, e.g. drug companies providing the trial with drugs free of charge. Non-commercial trials were trials that were funded via government funding or charity and had no funding links to commercial companies
dGraphics include tables, flow charts and images of any description
eOther disease/non-disease areas where singular clinical trials were conducted