Table 6 Subgroup analyses of methodological quality assessment (n/%).
Items (Yes) | All NMAs (n = 102) | Journal impact factor* | Year of publication# | Funding source | Country of corresponding author | Type of NMAs | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Low (<5.00) (n = 55) vs. High (≥5.00) (n = 32) | P-value | Older (n = 58) vs. Recent (n = 44) | P-value | Funding (n = 46) vs. Non-funding (n = 56) | P-value | China (n = 29) vs. Others (n = 73) | P-value | Bayesian NMAs (n = 61) vs. Adjusted indirect comparisons (n = 43)& | P-value | ||
Was the research question (i.e., research purpose, inclusion and exclusion criteria) clarified? | 62/60.78 | 31/56.36 vs. 20/62.50 | 0.568 | 33/56.90 vs. 29/65.91 | 0.358 | 26/56.52 vs. 36/64.29 | 0.426 | 20/68.97 vs. 42/57.53 | 0.288 | 38/62.30 vs. 25/58.14 | 0.671 |
Was there duplicate study selection and data extraction? | 74/72.55 | 38/69.09 vs. 24/75.00 | 0.547 | 41/70.69 vs. 33/75.00 | 0.631 | 32/69.57 vs. 42/75.00 | 0.543 | 26/89.66 vs. 48/65.75 | 0.015 | 50/81.97 vs. 26/60.47 | 0.015 |
Was a comprehensive literature search performed? | 58/56.86 | 25/45.45 vs. 25/78.13 | 0.002 | 31/53.45 vs. 27/61.36 | 0.426 | 26/56.52 vs. 32/57.14 | 0.950 | 16/55.17 vs. 42/57.53 | 0.829 | 43/70.49 vs. 17/39.53 | 0.002 |
Was the status of publication (i.e. grey literature) used as an inclusion criterion? | 81/79.41 | 43/78.18 vs. 26/81.25 | 0.728 | 46/79.31 vs. 35/79.55 | 0.977 | 35/76.09 vs. 46/82.14 | 0.454 | 26/89.66 vs. 55/75.34 | 0.109 | 53/86.89 vs. 29/67.44 | 0.017 |
Was a list of included studies provided? | 94/92.16 | 50/90.91 vs. 29/90.63 | 0.965 | 53/91.38 vs. 41/93.18 | 0.739 | 44/95.65 vs. 50/89.29 | 0.236 | 28/96.55 vs. 66/90.41 | 0.300 | 56/91.80 vs. 40/93.02 | 0.819 |
Were the characteristics of the included studies provided? | 100/98.04 | 54/98.18 vs. 31/96.88 | 0.715 | 58/100.00 vs. 42/95.45 | 0.103 | 45/97.83 vs. 55/98.21 | 0.889 | 29/100.00 vs. 71/97.26 | 0.370 | 59/96.72 vs. 43/100.00 | 0.233 |
Was the scientific quality of the included studies assessed and documented? | 70/68.63 | 34/61.82 vs. 25/78.13 | 0.098 | 32/55.17 vs. 38/86.36 | 0.001 | 29/63.04 vs. 41/73.21 | 0.273 | 25/86.21 vs. 45/61.64 | 0.016 | 48/78.69 vs. 24/55.81 | 0.013 |
Was the scientific quality of the included studies used appropriately in formulating conclusions? | 31/30.39 | 11/20.00 vs. 8/25.00 | 0.584 | 12/20.69 vs. 19/43.18 | 0.015 | 9/19.57 vs. 22/39.29 | 0.032 | 20/68.97 vs. 11/15.07 | 0.000 | 21/34.43 vs. 10/23.26 | 0.222 |
Were the methods used to combine the findings of studies appropriate? | 66/64.71 | 32/58.18 vs. 26/81.25 | 0.019 | 37/63.79 vs. 29/65.91 | 0.826 | 28/60.87 vs. 38/67.86 | 0.465 | 18/62.07 vs. 48/65.75 | 0.727 | 39/63.93 vs. 29/67.44 | 0.713 |
Was the likelihood of publication bias assessed? | 16/15.69 | 3/5.45 vs. 8/25.00 | 0.017 | 10/17.24 vs. 6/13.64 | 0.622 | 5/10.87 vs. 11/19.64 | 0.228 | 6/20.69 vs. 10/13.70 | 0.383 | 8/13.11 vs. 9/20.93 | 0.291 |
Was the conflict of interest stated? | 62/60.78 | 38/69.09 vs. 22/68.75 | 0.974 | 37/63.79 vs. 25/56.82 | 0.477 | 29/63.04 vs. 33/58.93 | 0.673 | 11/37.93 vs. 51/69.86 | 0.001 | 35/57.38 vs. 27/62.79 | 0.581 |
