Table 3. Trial characteristics associated with use of PROs as primary or coprimary outcomes versus secondary outcomes only or not used.
| PROs as primary or coprimary outcome (N = 144) | PROs secondary or not useda (N = 271) | Prevalence ratio (95% CI) | P valueb | |
|---|---|---|---|---|
|
Trial age group ≤18 years >65 years Other or mixture |
9 (27.3%) 8 (16.0%) 127 (38.3%) |
24 (72.7%) 42 (84.0%) 205 (61.7%) |
0.71 (0.40 to 1.27) 0.42 (0.22 to 0.80) Reference |
0.0056 |
|
Study setting Clinical Nonclinical or other |
114 (35.7%) 30 (31.3%) |
205 (64.3%) 66 (68.8%) |
1.14 (0.82 to 1.59) Reference |
0.4181 |
|
Trial design Individually randomized Cluster randomized |
108 (41.1%) 36 (23.7%) |
155 (58.9%) 116 (76.3%) |
1.73 (1.26 to 2.39) Reference |
0.0003 |
|
Country of recruitment LMIC only Non-LMIC or mixture |
5 (11.1%) 139 (37.6%) |
40 (89.9%) 231 (62.4%) |
0.30 (0.13 to 0.68) Reference |
0.0004 |
|
Region North America only Europe only Other or mixture |
69 (35.6%) 52 (41.3%) 23 (24.2%) |
125 (64.4%) 74 (58.7%) 72 (75.8%) |
1.47 (0.98 to 2.20) 1.70 (1.13 to 2,57) Reference |
0.0291 |
|
Type of interventionc Clinical Dietary or behavioral Other or mixture |
27 (24.3%) 62 (40.0%) 55 (36.9%) |
84 (75.7%) 93 (60.0%) 94 (63.1%) |
0.66 (0.45 to 0.97) 1.08 (0.81 to 1.44) Reference |
0.0233 |
|
Primary purposed Treatment Prevention Health services research Other |
75 (47.2%) 12 (14.8%) 32 (33.3%) 25 (31.6%) |
84 (52.8%) 69 (85.2%) 64 (66.7%) 54 (68.4%) |
1.49 (1.04 to 2.14) 0.47 (0.25 to 0.87) 1.03 (0.67 to 1.59) Reference |
<0.001 |
|
Type of funder Government, university, international agency Yes No Industry Yes No Foundation, special interest group, or other Yes No |
109 (34.0%) 34 (36.6%) 18 (24.0%) 126 (37.1%) 43 (34.7%) 111 (36.9%) |
212 (66.0%) 59 (63.4%) 57 (76.0%) 214 (62.9%) 81 (65.3%) 190 (63.1%) |
0.95 (0.70 to 1.29) Reference 0.65 (0.42 to 0.99) Reference 0.94 (0.71 to 1.25) Reference |
0.7333 0.0315 0.6680 |
| Impact factor e | 4.6 (2.8, 12.0) | 6.0 (3.9, 20.8) | NA | 0.0014f |
|
Patient/public engagement Yes No or unclear |
15 (38.5%) 129 (34.3%) |
24 (61.5%) 247 (65.7%) |
1.12 (0.74 to 1.71) Reference |
0.6040 |
|
Other stakeholder engagement Yes No or unclear |
17 (33.3%) 127 (34.9%) |
34 (66.6%) 237 (65.1%) |
0.96 (0.63 to 1.44) Reference |
0.8369 |
|
Publication Year 2014–2015 2016–2017 2018–2019 |
30 (28.0%) 68 (41.2%) 46 (32.2%) |
77 (72.0%) 97 (58.8%) 97 (67.8%) |
Reference 1.47 (1.03 to 2.09) 1.15 (0.78 to 1.69) |
0.6390g |
an = 2 trials with unclear use of PROs were included in this group.
bChi-squared test unless otherwise indicated.
cCategories obtained from ClinicalTrials.gov and grouped as follows: Clinical (Drug, Device, Biological, Procedure, Radiation, Genetic, Combination Product, Diagnostic Test); Dietary and behavioral (Dietary Supplement, Behavioral); Other (Other).
dCategories obtained from ClinicalTrials.gov and grouped as follows: Treatment (Treatment); Health Services Research (Health Services Research); Other (Prevention, Diagnostic, Supportive Care, Screening, Basic Science, Educational/Counseling/Training, Other).
eMedian (Q1, Q3).
fWilcoxon rank sum test; median, Q1, Q3.
gCochran–Armitage test for trend.
LMIC, low- or middle-income country; PRO, patient-reported outcome.