| Literature DB >> 28296925 |
Belle V van Rosmalen1, Ingo Alldinger2, Kasia P Cieslak1, Roos Wennink3, Mike Clarke4, Usama Ahmed Ali3, Marc G H Besselink1.
Abstract
INTRODUCTION: Publishing protocols of randomized controlled trials (RCT) facilitates a more detailed description of study rational, design, and related ethical and safety issues, which should promote transparency. Little is known about how the practice of publishing protocols developed over time. Therefore, this study describes the worldwide trends in volume and methodological quality of published RCT protocols.Entities:
Mesh:
Year: 2017 PMID: 28296925 PMCID: PMC5351864 DOI: 10.1371/journal.pone.0173042
Source DB: PubMed Journal: PLoS One ISSN: 1932-6203 Impact factor: 3.240
Baseline and general characteristics of 596 published protocols of RCTs.
| General characteristics | First period Sept 2001-Dec 2004 | Second period Jan 2005-May 2008 | Third period Jun 2008-Sept 2011 | |
|---|---|---|---|---|
| (number) (percentage) | (n) (%) | (n) (%) | (n) (%) | |
| Total | 69 (12) | 137 (23) | 390 (65) | <0.0001 |
| Region; | ||||
| Europe | 24 (35) | 65 (47) | 190 (49) | |
| North America | 30 (44) | 46 (34) | 103 (26) | |
| Australasia | 11 (16) | 25 (18) | 86 (22) | |
| Other | 4 (6) | 1 (1) | 11 (3) | 0.02 |
| Specialty; | ||||
| Internal medicine and paediatrics | 35 (51) | 75 (55) | 164 (42) | |
| Primary care | 23 (33) | 38 (28) | 115 (40) | |
| Surgery | 6 (9) | 19 (14) | 41 (11) | |
| Other | 5 (7) | 5 (4) | 30 (8) | 0.06 |
| Participating countries; | ||||
| Single country | 42 (61) | 94 (69) | 312 (80) | |
| Two or more countries | 22 (32) | 31 (23) | 68 (17) | |
| Missing | 5 (7) | 12 (9) | 10 (3) | 0.006 |
| Participating centres; | ||||
| Single | 8 (12) | 28 (20) | 94 (24) | |
| Multi | 61 (88) | 109 (80) | 296 (76) | 0.06 |
| Funding; | ||||
| Commercial | 33 (48) | 46 (34) | 113 (29) | |
| Non-commercial | 36 (52) | 91 (66) | 277 (71) | 0.008 |
| Trial design; | ||||
| Parallel | 56 (81) | 120 (88) | 325 (83) | |
| Other/Mixed | 13 (19) | 17 (12) | 65 (17) | 0.39 |
| Number of study arms reported; | ||||
| Two arms | 43 (62) | 105 (77) | 299 (77) | |
| Three or more arms | 26 (38) | 32 (23) | 90 (23) | 0.032 |
| Number of randomized patients; | 640 | 358 | 336 | |
| Median (IQR) | (308–2741) | (197–852) | (140–900) | |
| Written informed consent present; | 41 (59) | 106 (77) | 287 (74) | 0.02 |
| Data safety Committee present; | 37 (54) | 57 (42) | 139 (37) | 0.02 |
| Plan for adverse events present; | 17 (25) | 50 (37) | 145 (37) | 0.13 |
Legend: This table describes all general characteristics of the included protocols, divided period by of publication. Study groups were compared by Fisher exact, χ2 and Mann-Whitney U tests, as appropriate. A p-value of <0.05 was considered significant. IQR = inter quartile range.
Quality characteristics of published protocols.
| Individual quality characteristics | First period Sept 2001-Dec 2004 n = 69 | Second period Jan 2005-May 2008 n = 137 | Third period Jun 2008-Sept 2011 n = 390 | |
|---|---|---|---|---|
| (number) (percentage) | (n) (%) | (n) (%) | (n) (%) | |
| Primary outcome specified; | 65 (94) | 134 (98) | 380 (97) | 0.3 |
| Sample size calculation reported; | 64 (93) | 123 (90) | 359 (92) | 0.7 |
| Adequate generation of allocation; | 30 (44) | 79 (56) | 260 (67) | 0.001 |
| Concealment of allocation; | 26 (38) | 72 (53) | 215 (55) | 0.03 |
| Any Blinding; | 50 (73) | 90 (66) | 268 (69) | 0.60 |
| Blinding—patient; | ||||
| Yes | 27 (39) | 50 (37) | 103 (26) | |
| No | 35 (51) | 75 (55) | 274 (70) | |
| Unclear | 7 (10) | 12 (9) | 13 (3) | 0.02 |
| Blinding—observer; | ||||
| Yes | 33 (48) | 67 (49) | 235 (60) | |
| No | 22 (32) | 48 (35) | 122 (31) | |
| Unclear | 14 (20) | 22 (16) | 33 (9) | 0.02 |
| Blinding—physician; | ||||
| Yes | 25 (36) | 37 (27) | 76 (20) | |
| No | 36 (52) | 86 (63) | 297 (76) | |
| Unclear | 8 (12) | 14 (10) | 17 (4) | 0.005 |
| Blinding—adjudication committee; | ||||
| Yes | 17 (25) | 22 (16) | 40 (10) | |
| No | 52 (75) | 114 (83) | 350 (90) | |
| Unclear | 0 (0) | 1 (1) | 0 (0) | 0.003 |
| Double blinding; | 27 (39) | 49 (36) | 97 (25) | 0.008 |
| Prospective subgroup analyses; | 16 (23) | 37 (27) | 80 (21) | 0.3 |
| Intention to treat analyses; | 43 (62) | 97 (71) | 293 (75) | 0.08 |
| High quality protocols; | 18 (26) | 43 (31) | 143 (37) | 0.2 |
Legend: This table describes all characteristics concerning methodological quality, subdivided by period of publication. Study groups were compared by Fisher exact, χ2 and Mann-Whitney U tests, as appropriate. A p-value of <0.05 was considered significant.
* defined as presence of the following 3 criteria: adequate generation of allocation, concealment of allocation and intention-to-treat analysis.
Subgroup analyses by region and speciality.
| Individual quality characteristics | Europe n = 279 | North America n = 179 | Australasia n = 122 | |
| (number) (percentage) | (n) (%) | (n) (%) | (n) (%) | |
| Sample size calculation reported; | 253 (91) | 161 (90) | 116 (95) | 0.3 |
| Primary outcome specified; | 274 (98) | 167 (93) | 122 (100) | 0.001 |
| Generation of allocation; | 183 (66) | 94 (53) | 79 (65) | 0.01 |
| Concealment of allocation; | 154 (55) | 77 (43) | 72 (59) | 0.009 |
| Some blinding; | 182 (65) | 125 (70) | 88 (72) | 0.3 |
| Blinding–patient; | 71 (25) | 66 (37) | 34 (28) | 0.03 |
| Blinding–observer; | 165 (59) | 91 (51) | 72 (59) | 0.2 |
| Blinding–physician; | 47 (17) | 61 (34) | 22 (18) | <0.0001 |
| Blinding–adjudication committee; | 20 (7) | 37 (21) | 17 (14) | <0.0001 |
| Double blinding; | 68 (24) | 65 (36) | 31 (25) | 0.02 |
| Prospective subgroup analyses; | 68 (24) | 40 (22) | 23 (19) | 0.5 |
| Intention to treat analyses; | 221 (79) | 108 (60) | 93 (76) | <0.0001 |
| High quality protocols; | 99 (36) | 45 (25) | 53 (43) | 0.003 |
| Individual quality characteristics | Internal & paediatrics n = 274 | Primary care n = 216 | Surgery n = 66 | |
| (number) (percentage) | (n) (%) | (n) (%) | (n) (%) | |
| Sample size calculation reported; | 256 (93) | 194 (90) | 61 (92) | 0.34 |
| Primary outcome specified; | 271 (99) | 206 (95) | 64 (97) | 0.06 |
| Generation of allocation; | 153 (56) | 140 (65) | 48 (73) | 0.02 |
| Concealment of allocation; | 120 (44) | 127 (59) | 38 (58) | 0.002 |
| Some blinding; | 213 (78) | 129 (60) | 33 (50) | <0.0001 |
| Blinding–patient; | 107 (39) | 35 (16) | 18 (27) | <0.0001 |
| Blinding–observer; | 156 (57) | 120 (56) | 29 (44) | 0.16 |
| Blinding–physician; | 89 (33) | 24 (11) | 13 (20) | <0.0001 |
| Blinding–adjudication committee; | 66 (24) | 7 (3) | 3 (5) | <0.0001 |
| Double blinding; | 104 (38) | 33 (15) | 18 (27) | <0.0001 |
| Prospective subgroup analyses; | 68 (25) | 41 (19) | 14 (21) | 0.30 |
| Intention to treat analyses; | 194 (71) | 158 (73) | 49 (74) | 0.78 |
| High quality protocols; | 77 (28) | 80 (37) | 29 (44) | 0.02 |
Legend: This table describes the subgroup analysis for methodological quality characteristics subdivided by specialty or region. Study groups were compared by Fisher exact, χ2 and Mann-Whitney U tests, as appropriate. A p-value of <0.05 was considered significant.
* Presence of the following three criteria: adequate generation of allocation, concealment of allocation and intention-to-treat analysis.
Regression analyses for high protocol quality.
| Univariate regression analyses; Characteristics | (n) | Odds for high quality. OR (95% CI) | |
| Region; | |||
| Europe | 279 | 1 | - |
| North America | 179 | 0.61 (0.40–0.93) | 0.02 |
| Australasia | 122 | 1.40 (0.91–2.20) | 0.13 |
| Specialty; | |||
| Internal medicine and Paediatrics | 274 | 1 | - |
| Primary care | 216 | 1.51 (1.03–2.20) | 0.04 |
| Surgery | 66 | 2.01 (1.15–3.47) | 0.01 |
| Number of participating countries; Single country | 448 | 0.86 (0.57–1.31) | 0.5 |
| Participating centres; Single | 130 | 0.68 (0.44–1.04) | 0.08 |
| Funding; Commercial | 192 | 1.14 (0.79–1.64) | 0.5 |
| Trial design; parallel | 501 | 1.15 (0.72–1.85) | 0.6 |
| Two study arms reported; Yes | 447 | 0.95 (0.64–1.41) | 0.8 |
| Written informed consent; Yes | 434 | 1.50 (1.01–2.23) | 0.04 |
| Data safety committee present; Yes | 233 | 1.18 (0.83–1.66) | 0.4 |
| Plan adverse events; Yes | 212 | 1.69 (1.19–2.40) | 0.003 |
| Multivariate regression analyses; Characteristics | (n) | Odds for high quality. OR (95% CI) | |
| Region; | |||
| Europe | 257 | 1 | |
| North America | 168 | 0.63 (0.40–0.99) | 0.04 |
| Australasia | 117 | 1.30 (0.82–2.06) | 0.3 |
| Specialty; | |||
| Internal and paediatrics | 262 | 1 | |
| Primary care | 214 | 1.57 (1.04–2.36) | 0.03 |
| Surgical specialties | 66 | 1.94 (1.09–3.45) | 0.02 |
| Written informed consent; Yes | 434 | 1.42 (0.90–2.23) | 0.13 |
| Plan adverse events; Yes | 212 | 1.81 (1.22–2.68) | 0.003 |
Legend: This table describes odds ratio (OR) with the corresponding 95% confidence intervals (95% CIs), and was calculated for comparison of methodological quality between subgroups by means of univariate and multivariate logistic regression. A p-value of <0.05 was considered significant.
*The small number of protocols from regions labelled as “other” (e.g. Africa and South America) were not included in the multivariate analysis, but are reported in Table 1.