Table 2.
Trial demographics by journal
| Journal (N in cohort) | Total (N = 264) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| BMJ (N = 16) | NEJM (N = 55) | Lancet (N = 66) | HTA (N = 127) | |||||||||
| n | n/N% | n | n/N% | n | n/N% | n | n/N% | n | n/N% | |||
| Trial rationale | Explanatory | 0 | 0.0 | 0 | 0.0 | 5 | 7.6 | 2 | 1.6 | 7 | 2.7 | |
| Pragmatic | 6 | 37.5 | 2 | 3.6 | 10 | 15.2 | 88 | 69.3 | 106 | 40.2 | ||
| Not specified or clear | 10 | 62.5 | 53 | 96.4 | 51 | 77.3 | 37 | 29.1 | 151 | 57.2 | ||
| Funder origin | Asia | 0 | 0.0 | 1 | 1.8 | 3 | 4.5 | 0 | 0.0 | 4 | 1.5 | |
| Japan | 0 | 0.0 | 1 | 1.8 | 2 | 3.0 | 0 | 0.0 | 3 | 1.1 | ||
| South Korea | 0 | 0.0 | 0 | 0.0 | 1 | 1.5 | 0 | 0.0 | 1 | 0.4 | ||
| Australia | 1 | 6.3 | 2 | 3.6 | 3 | 4.5 | 0 | 0.0 | 6 | 2.3 | ||
| Australia | 1 | 6.3 | 2 | 3.6 | 2 | 3.0 | 0 | 0.0 | 4 | 1.5 | ||
| New Zealand | 0 | 0.0 | 0 | 0.0 | 1 | 1.5 | 0 | 0.0 | 2 | 0.8 | ||
| Europe | 14 | 87.5 | 21 | 38.2 | 40 | 60.6 | 127 | 100.0 | 202 | 76.5 | ||
| Belgium | 0 | 0.0 | 1 | 1.8 | 0 | 0.0 | 0 | 0.0 | 1 | 0.4 | ||
| Denmark | 3 | 18.8 | 2 | 3.6 | 0 | 0.0 | 0 | 0.0 | 5 | 1.9 | ||
| Finland | 1 | 6.3 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 1 | 0.4 | ||
| France | 0 | 0.0 | 2 | 3.6 | 5 | 7.6 | 0 | 0.0 | 7 | 2.7 | ||
| Germany | 0 | 0.0 | 1 | 1.8 | 6 | 9.1 | 0 | 0.0 | 7 | 2.7 | ||
| Ireland | 1 | 6.3 | 0 | 0.0 | 2 | 3.0 | 0 | 0.0 | 3 | 1.1 | ||
| Netherlands | 2 | 12.5 | 1 | 1.8 | 2 | 3.0 | 0 | 0.0 | 5 | 1.9 | ||
| Spain | 0 | 0.0 | 0 | 0.0 | 1 | 1.5 | 0 | 0.0 | 1 | 0.4 | ||
| Sweden | 0 | 0.0 | 0 | 0.0 | 1 | 1.5 | 0 | 0.0 | 1 | 0.4 | ||
| Switzerland | 1 | 6.3 | 4 | 7.3 | 3 | 4.5 | 0 | 0.0 | 8 | 3.0 | ||
| United Kingdom | 6 | 37.5 | 9 | 16.4 | 19 | 28.8 | 127 | 100.0 | 161 | 61.0 | ||
| Other (European Union) | 0 | 0.0 | 1 | 1.8 | 1 | 1.5 | 0 | 0.0 | 2 | 0.8 | ||
| North America | 1 | 6.3 | 30 | 54.5 | 20 | 30.3 | 0 | 0.0 | 51 | 19.3 | ||
| Canada | 0 | 0.0 | 1 | 1.8 | 0 | 0.0 | 0 | 0.0 | 1 | 0.4 | ||
| United States of America | 1 | 6.3 | 29 | 52.7 | 20 | 30.3 | 0 | 0.0 | 50 | 18.9 | ||
| Not specified | 0 | 0.0 | 1 | 1.8 | 0 | 0.0 | 0 | 0.0 | 1 | 0.4 | ||
| Recruitment setting | Primary | 4 | 25.0 | 2 | 3.6 | 5 | 7.6 | 46 | 36.2 | 57 | 21.6 | |
| Secondary only | 2 | 12.5 | 2 | 3.6 | 5 | 7.6 | 17 | 13.4 | 26 | 9.8 | ||
| Tertiary only | 3 | 18.8 | 17 | 30.9 | 30 | 45.5 | 47 | 37.0 | 97 | 36.7 | ||
| Secondary or tertiary (not specified) | 0 | 0.0 | 0 | 0.0 | 2 | 3.0 | 3 | 2.4 | 5 | 1.9 | ||
| Community | 7 | 43.8 | 4 | 7.3 | 2 | 3.0 | 15 | 11.8 | 28a | 10.6 | ||
| Emergency | 1 | 6.3 | 5 | 9.1 | 0 | 0.0 | 7 | 5.5 | 13 | 4.9 | ||
| Hospice | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | ||
| Social care | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | ||
| Other setting | 0 | 0.0 | 1 | 1.8 | 1 | 1.5 | 0 | 0.0 | 2b | 0.8 | ||
| Not clear | 0 | 0.0 | 32 | 58.2 | 22 | 33.3 | 9 | 7.1 | 63c | 23.9 | ||
| Trial design | Parallel | 13 | 81.3 | 48 | 87.3 | 59 | 89.4 | 103 | 81.1 | 233 | 88.3 | |
| Sequential | 0 | 0.0 | 1 | 1.8 | 1 | 1.5 | 1 | 0.8 | 3 | 1.1 | ||
| Crossover | 0 | 0.0 | 1 | 1.8 | 2 | 3.0 | 5 | 3.9 | 9 | 3.4 | ||
| Cluster | 2 | 12.5 | 0 | 0.0 | 2 | 3.0 | 11 | 8.7 | 15 | 5.7 | ||
| Factorial | 1 | 6.3 | 5 | 9.1 | 2 | 3.0 | 7 | 5.5 | 15 | 5.7 | ||
| Number of trial arms | 2 | 12 | 75.0 | 42 | 76.4 | 46 | 69.7 | 85 | 66.9 | 185 | 70.1 | |
| 3 | 3 | 18.8 | 7 | 12.7 | 10 | 15.2 | 29 | 22.8 | 49 | 18.6 | ||
| 4 | 1 | 6.3 | 4 | 7.3 | 4 | 6.1 | 7 | 5.5 | 16 | 6.1 | ||
| 5 | 0 | 0.0 | 2 | 3.6 | 2 | 3.0 | 5 | 3.9 | 9 | 3.4 | ||
| 6 or more | 0 | 0.0 | 0 | 0.0 | 4 | 6.1 | 1 | 0.8 | 5d | 1.9 | ||
| Type of intervention e, f | Pharmaceutical | 3 | 18.8 | 41 | 74.5 | 54 | 81.8 | 34 | 26.8 | 132 | 50.0 | |
| Cellular and gene therapy | 0 | 0.0 | 1 | 1.8 | 2 | 3.0 | 0 | 0.0 | 3 | 1.1 | ||
| Medical device | 0 | 0.0 | 5 | 9.1 | 5 | 7.6 | 16 | 12.6 | 26 | 9.8 | ||
| Surgery | 0 | 0.0 | 3 | 5.5 | 1 | 1.5 | 10 | 7.9 | 14 | 5.3 | ||
| Radiotherapy | 0 | 0.0 | 1 | 1.8 | 3 | 4.5 | 9 | 7.1 | 13 | 4.9 | ||
| Psychological and behavioural | 6 | 37.5 | 0 | 0.0 | 1 | 1.5 | 22 | 17.3 | 29 | 11.0 | ||
| Physical | 2 | 12.5 | 2 | 3.6 | 0 | 0.0 | 10 | 7.9 | 14 | 5.3 | ||
| Complimentary | 0 | 0.0 | 0 | 0.0 | 1 | 1.5 | 5 | 3.9 | 6 | 2.3 | ||
| Resources and infrastructure | 1 | 6.3 | 1 | 1.8 | 1 | 1.5 | 19 | 15.0 | 22 | 8.3 | ||
| Other | 4 | 25.0 | 2 | 3.6 | 1 | 1.5 | 12 | 9.4 | 19 | 7.2 | ||
| Number of primary outcomes | 1 | 11 | 68.8 | 47 | 85.5 | 51 | 77.3 | 101 | 79.5 | 210 | 79.5 | |
| 2 | 2 | 12.5 | 3 | 5.5 | 10 | 15.2 | 13 | 10.2 | 28 | 10.6 | ||
| 3 | 1 | 6.3 | 4 | 7.3 | 2 | 3.0 | 1 | 0.8 | 8 | 3.0 | ||
| 4 or more | 2 | 12.5 | 1 | 1.8 | 2 | 3.0 | 11 | 8.7 | 16 | 6.1 | ||
| Primary outcome type | Subjective | 1 primary outcome | 3 | 18.8 | 0 | 0.0 | 2 | 3.0 | 39 | 30.7 | 44 | 16.7 |
| 2 + primary outcomes | 1 | 6.3 | 0 | 0.0 | 0 | 0.0 | 4 | 3.1 | 5 | 1.9 | ||
| Objective | 1 primary outcome | 6 | 37.5 | 46 | 83.6 | 46 | 69.7 | 53 | 41.7 | 151 | 57.2 | |
| 2 + primary outcomes | 3 | 18.8 | 6 | 10.9 | 13 | 19.7 | 6 | 4.7 | 28 | 10.6 | ||
| Both | 1 primary outcome | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 3 | 2.4 | 3g | 1.1 | |
| 2 + primary outcomes | 1 | 6.3 | 2 | 3.6 | 1 | 1.5 | 14 | 11.0 | 18 | 6.8 | ||
| Not clear | 1 primary outcome | 2 | 12.5 | 1 | 1.8 | 3 | 4.5 | 6 | 4.7 | 12 | 4.5 | |
| 2 + primary outcomes | 0 | 0.0 | 0 | 0.0 | 1 | 1.5 | 2 | 1.6 | 3 | 1.1 | ||
| Allocation ratio | Equal e.g. 1:1 | 13 | 81.3 | 46 | 83.6 | 55 | 83.3 | 115 | 90.6 | 229 | 86.7 | |
| Not equal e.g. 2:1 | 2 | 12.5 | 8 | 14.5 | 10 | 15.2 | 12 | 9.4 | 32 | 12.1 | ||
| Not clear | 1 | 6.3 | 1 | 1.8 | 1 | 1.5 | 0 | 0.0 | 3 | 1.1 | ||
| Unit of randomisation | Individual | 12 | 75.0 | 52 | 94.5 | 62 | 93.9 | 113 | 89.0 | 239 | 90.5 | |
| GP practice | 0 | 0.0 | 0 | 0.0 | 1 | 1.5 | 9 | 7.1 | 10 | 3.8 | ||
| Dyad (e.g. mother-child) | 1 | 6.3 | 1 | 1.8 | 1 | 1.5 | 2 | 1.6 | 5 | 1.9 | ||
| Other | 3 | 18.8 | 2 | 3.6 | 2 | 3.0 | 3 | 2.4 | 10h | 3.8 | ||
| Blinding | Yes, blinding | 11 | 68.8 | 37 | 67.3 | 45 | 68.2 | 69 | 54.3 | 162 | 61.4 | |
| No, not blinded | Justification provided | 2 | 12.5 | 3 | 5.5 | 5 | 7.6 | 33 | 26.0 | 43i | 16.3 | |
| Justification not provided | 1 | 6.3 | 9 | 16.4 | 15 | 22.7 | 10 | 7.9 | 35 | 13.3 | ||
| Not clear | 2 | 12.5 | 6 | 10.9 | 1 | 1.5 | 15 | 11.8 | 24 | 9.1 | ||
BMJ British Medical Journal, HTA Health Technology Assessment Monograph series, NEJM New England Journal of Medicine
aAdvertisements in newsletters (n = 1); Child and Adolescent Mental Health Services (n = 1); Community mental health teams (n = 1); Community nurse services (n = 1); Community nursing services and community leg ulcers clinics (n = 1); Community old age psychiatry services (n = 1); Community sources (n = 1); Department of Veterans Affairs (n = 3); National population registrar (n = 1); Community paediatricians (n = 1); Registrar (n = 3); Schools (n = 1); Secondary schools (n = 1); University podiatry schools and podiatry clinics (n = 1); Vaccination centres in schools (n = 1); Villages (n = 1); Not specified (n = 8)
bOther setting: Veterans Affairs Medical Centre (n = 1); From other trials (n = 1)
cNot clear: Adult mental health setting (n = 1); Antenatal clinic (n = 1); Centres (n = 29); Child and Adolescent Mental Health Services (n = 1); Child Development Centre (n = 1); Clinic site (n = 1); Clinical centres (n = 1); Clinical sites (n = 1), Clinics (n = 2); Countries (n = 2); European medical centres (n = 1); Institutes (n = 1); Institutions (n = 1); Sites (n = 13); Not described (n = 7)
dTotal arms equal to: six (n = 2); eight (n = 1); nine (n = 1); twelve (n = 1)
eDefined by UK Clinical Research Collaboration Health Research Classification System
fCategories not mutually exclusive
gBoth: Composite (n = 3) (Disease improvement calculated from CHAQ, physician’ global assessment of disease activity, parents’ global assessment of overall well-being, number of joints with limited range of movement (ROM), number of active joints and erythrocyte sedimentation rate (n = 1)); Foot and Ankle Outcome Score (n = 1); Post-operative nausea and vomiting (n = 1)
hOther units of randomisation: Clinic (n = 1); Family (n = 2); Hospital (n = 1); Household (n = 1); Partner (n = 1); School (n = 1); Village (n = 1); Year group (n = 1); Paediatric diabetes services (n = 1)
iJustification for no blinding: Not possible or practical due to nature of intervention or trial design (n = 30); Not possible/practical as in practice caused difficulties for patients (n = 1); Not possible/practical as shown by other similar trials (n = 2); Not possible/practical so cluster randomisation approach used (n = 1); Not possible – no additional justification given (n = 4); Attempted to blind although were not successful (n = 1); Large sample size means that results are not compromise (n = 1); Not blinding reflects real practice (n = 2); Test for impact of not blinding post trial (n = 1)