Introduction
Methods
Eligibility criteria
Literature search and screening
Data collection
Statistical analysis
Results
Category by items | All publications (N = 529) |
---|---|
No. of authors [median (first to third quartile)] | 6 (4 to 8) |
≤ 4 | 171 (32.33%) |
5 ~ 8 | 278 2.55%) |
> 8 | 80 (15.12%) |
Year of publish | |
2011 | 35 (6.62%) |
2012 | 44 (8.32%) |
2013 | 56 (10.59%) |
2014 | 117 (22.12%) |
2015 | 120 (22.68%) |
2016 | 85 (16.07%) |
2017 (up to July-31) | 72 (13.61%) |
Database searched [median ((first to third quartile))] | 2 (2 to 3) |
≤ 1 | 61 (11.53%) |
2 ~ 3 | 385 (72.78%) |
> 3 | 83 (15.69%) |
Journal distribution (n = 174 for journal numbers) | |
Specialist journal | 410 (77.50%) |
General journal | 119 (22.50%) |
Methodologist involved | |
Yes | 349 (65.97%) |
No | 180 (34.03%) |
Design of source study | |
Cohort | 318 (60.11%) |
Case-control | 7 (1.32%) |
Cross-section | 3 (0.57%) |
Mixed | 199 (37.62%) |
CCT and RCT | 2 (0.38%) |
Classification of subject | |
Epidemiology | 525 (99.24%) |
Intervention | 1 (0.19%) |
Prognosis | 2 (0.38%) |
Diagnose | 1 (0.19%) |
Primary outcome | |
Cancer | 260 (49.15%) |
CVD | 118 (22.31%) |
Type 2 Diabetes | 45 (8.51%) |
Fracture and Osteoarthritis | 21 (3.97%) |
CVD and Cancer/Diabetes | 13 (2.46%) |
Metabolic Syndrome or Obesity | 13 (2.46%) |
Pregnancy Outcomes (e.g. neonatal death, low birth weight) | 12 (2.27%) |
Dementia/Cognitive impairment/Alzheimer’s Disease/Parkinson’s disease | 12 (2.27%) |
Depression | 6 (1.13%) |
Digestive tract disease (e.g. pancreatitis, gallbladder disease) | 12 (2.27%) |
Urinary System disease (e.g. urolithiasis) | 6 (1.13%) |
Others (e.g. Cataract, Gout) | 12 (2.27%) |
No. of included studies [median ((first to third quartile))] | 14 (10 to 21) |
≤ 10 | 151 (28.54%) |
11 ~ 21 | 247 (46.69%) |
> 21 | 130 (24.57%) |
Missing | 1 (0.19%) |
Region | |
Asian | 350 (66.16%) |
European | 129 (24.39%) |
America | 47 (8.88%) |
Australia | 3 (0.57%) |
Reporting checklist | |
PRISMA | 109 (20.60%) |
MOOSE | 204 (38.56%) |
PRISMA + MOOSE | 31 (5.86%) |
Other | 6 (1.13%) |
None | 179 (33.84%) |
Model used in trend approximationa | |
RCS regression | 295 (55.77%) |
FP regression | 61 (11.53%) |
Other non-linear regression | 21 (3.97%) |
Linear | 152 (28.73%) |
Funding | |
Yes | 337 (63.71%) |
No | 54 (10.21%) |
Not reported | 138 (26.09%) |
Reporting quality of included SR-DRMAs
Study characteristics associated with reporting quality
Influential factors | Estimated regression coefficients (95%CI) | |||
---|---|---|---|---|
Multivariable | P-value | Sensitivity analysis | P-value | |
No. of authors | ||||
≤ 4 | Reference | Reference | ||
5 ~ 6 | 0.78 (0.35, 1.20) | < 0.001 | 0.73 (0.28, 1.18) | 0.002 |
7~ 8 | 0.86 (0.37, 1.36) | 0.001 | 0.68 (0.18, 1.19) | 0.008 |
> 8 | 1.15 (0.61, 1.70) | < 0.001 | 0.99 (0.48, 1.49) | < 0.001 |
Year of publication | ||||
2011 | Reference | Reference | ||
2012 | 0.39 (−0.41, 1.20) | 0.338 | 0.77 (− 0.05, 1.58) | 0.066 |
2013 | 1.23 (0.28, 2.18) | 0.011 | 1.12 (0.18, 2.05) | 0.020 |
2014 | 0.93 (0.13, 1.74) | 0.023 | 1.08 (0.20, 1.96) | 0.016 |
2015 | 1.35 (0.58, 2.11) | 0.001 | 1.39 (0.54, 2.25) | 0.001 |
2016 | 2.01 (1.28, 2.75) | < 0.001 | 2.19 (1.38, 3.00) | < 0.001 |
2017 (up to July-31) | 2.39 (1.60, 3.18) | < 0.001 | 2.56 (1.62, 3.52) | < 0.001 |
Linear trend test | 0.38 (0.28, 0.47) | < 0.001 | 0.38 (0.27, 0.50) | < 0.001 |
Use of reporting guidance | ||||
No | Reference | Reference | ||
Yes | 0.98 (0.63, 1.32) | < 0.001 | 0.99 (0.61, 1.37) | < 0.001 |
Region | ||||
European | Reference | Reference | ||
Asia Pacific | −0.21 (− 0.66, 0.23) | 0.348 | − 0.28 (− 0.74, 0.17) | 0.224 |
America | − 0.18 (−1.31, 0.95) | 0.752 | − 0.54 (−1.61, 0.53) | 0.320 |
Methodologist involved | ||||
No | Reference | Reference | ||
Yes | 0.86 (0.42, 1.32) | < 0.001 | 0.78 (0.36, 1.19) | < 0.001 |
Influential factors | Reporting domains and estimated regression coefficients | |||||||
---|---|---|---|---|---|---|---|---|
Title and Introduction | P-value | Methods | P-value | Results | P-value | Conclusion | P-value | |
No. of authors | ||||||||
≤ 4 | Reference | Reference | Reference | Reference | ||||
5 ~ 6 | 0.02 (−0.03, 0.06) | 0.457 | 0.50 (0.20, 0.80) | 0.001 | 0.17 (0.03, 0.31) | 0.018 | 0.20 (0.05, 0.36) | 0.011 |
7~ 8 | −0.01 (− 0.05, 0.04) | 0.819 | 0.57 (0.22, 0.92) | 0.002 | 0.09 (−0.05, 0.23) | 0.208 | 0.10 (−0.10, 0.30) | 0.315 |
> 8 | 0.04 (−0.02, 0.09) | 0.179 | 0.64 (0.23, 1.04) | 0.002 | 0.10 (−0.07, 0.27) | 0.253 | 0.33 (0.12, 0.55) | 0.003 |
Year of publication | ||||||||
2011 | Reference | Reference | Reference | Reference | ||||
2012 | 0.01 (−0.00, 0.02) | 0.198 | 0.37 (−0.30, 1.04) | 0.279 | 0.36 (0.05, 0.68) | 0.025 | −0.29 (− 0.69, 0.11) | 0.157 |
2013 | 0.00 (−0.01, 0.01) | 0.819 | 0.68 (−0.04, 1.41) | 0.062 | 0.45 (0.15, 0.75) | 0.004 | −0.15 (− 0.49, 0.19) | 0.387 |
2014 | 0.01 (0.00, 0.02) | 0.048 | 0.49 (0.06, 1.33) | 0.142 | 0.54 (0.23, 0.85) | 0.001 | −0.19 (− 0.55, 0.18) | 0.318 |
2015 | 0.00 (−0.02, 0.02) | 0.964 | 0.69 (0.06, 1.33) | 0.032 | 0.65 (0.34, 0.96) | < 0.001 | −0.04 (− 0.40, 0.31) | 0.818 |
2016 | −0.00 (− 0.02, 0.01) | 0.709 | 1.03 (0.41, 1.64) | 0.001 | 0.81 (0.53, 1.08) | < 0.001 | 0.10 (−0.24, 0.45) | 0.552 |
2017 (up to July-31) | 0.00 (−0.02, 0.01) | 0.914 | 1.50 (0.82, 2.18) | < 0.001 | 0.83 (0.53, 1.13) | < 0.001 | −0.16 (− 0.53, 0.21) | 0.399 |
Use of reporting guidance | ||||||||
No | Reference | Reference | Reference | Reference | ||||
Yes | −0.00 (−0.02, 0.04) | 0.083 | 0.57 (0.32, 0.82) | < 0.001 | 0.25 (0.13, 0.38) | < 0.001 | 0.17 (0.03, 0.32) | 0.020 |
Region | ||||||||
European | Reference | Reference | Reference | Reference | ||||
Asia Pacific | −0.03 (−0.06, − 0.001) | 0.042 | − 0.45 (− 0.77, − 0.13) | 0.006 | 0.24 (0.07, 0.41) | 0.005 | −0.10 (− 0.26, 0.06) | 0.230 |
America | 0.00 (−0.06, 0.01) | 0.637 | −0.14 (− 0.93, 0.65) | 0.720 | −0.08 (− 0.36, 0.19) | 0.552 | −0.14 (− 0.39, 0.12) | 0.302 |
Methodologist involved | ||||||||
No | Reference | Reference | Reference | Reference | ||||
Yes | −0.00 (−0.02, 0.02) | 0.859 | 0.32 (0.06, 0.58) | 0.015 | 0.10 (−0.02, 0.22) | 0.095 | 0.40 (0.24, 0.56) | < 0.001 |