Table 4 Screening, extraction and risk of bias assessment in the included systematic reviews (the HTA data were collected for this study; all other data are from Page et al. [1], i.e. the data collected for 300 systematic reviews for a single month in 2004 and 2014)
From: Nature and reporting characteristics of UK health technology assessment systematic reviews
Characteristic | 2004 n = 300 [1] | HTA 2004 n = 23 | HTA 2014 n = 30 | Cochrane 2014 n = 45 [1] | 2014 n = 300 [1] |
|---|---|---|---|---|---|
Screening | |||||
By at least two authors | NR | 14 (61%) | 22 (73%) | 44 (98%) | 200 (67%) |
By one author, with a sample screened by a second | NR | 2 (9%) | 3 (10%) | 1 (2%) | 7 (2%) |
By one author only | NR | 2 (9%) | 1 (3%) | 0 (0%) | 6 (2%) |
Not reported / Unclear | NR | 5 (22%) | 4 (13%) | 0 (0%) | 87 (29%) |
Empty review (no included / eligible studies) | NR | 0/23 (0%) | 2/30 (7%) | 3/45 (7%) | 4/300 (1%) |
Extraction | NR | n = 23 | n = 28 | n = 42 | n = 296 |
By at least two authors | NR | 4 (17%) | 5 (18%) | 41 (98%) | 163 (55%) |
By one author, with data verified by a second | NR | 14 (61%) | 19 (68%) | 0 (0%) | 29 (10%) |
By one author only | NR | 1 (4%) | 2 (7%) | 0 (0%) | 7 (2%) |
Not reported / Unclear | NR | 4 (17%) | 2 (7%) | 1 (2%) | 97 (33%) |
Quality assessment | - (67%) | 23 (100%) | 28 (100%) | 42 (100%) | 206 (70%) |
By at least two authors | NR | 5 (22%) | 10 (36%) | 37 (88%) | 121/206 (59%) |
By one author, with data verified by a second | NR | 11 (48%) | 12 (43%) | 0 (0%) | 6/206 (3%) |
By one author only | NR | 1 (4%) | 0 (0%) | 0 (0%) | 3/206 (1%) |
Not reported | NR | 6 (26%) | 6 (21%) | 5 (12%) | 76/206 (37%) |
Risk of bias / quality assessment tool | |||||
Cochrane (or modification) | NR | 2 (9%) | 12 (43%) | 37 (88%) | 77 (37%) |
Jadad | NR | 4 (17%) | 0 (0%) | 0(0%) | 33 (11%) |
Newcastle-Ottowa | NR | 0 | 0 (0%) | 1 (2%) | 17 (8%) |
QUADAS, QUADAS-2 | NR | 1 (4%) | 5 (18%) | 0 (0%) | 8 (4%) |
Own | NR | 2 (9%) | 3 (11%) | 2 (5%) | 38 (18%) |
Other | NR | 14 (61%)a | 9 (32%)a | 3 (7%) | 53 (26%) |
Not reported | NR | 1 (4%) | 1 (4%) | 0 (0%) | 6 (3%) |
Selective reportingb | NR | 0 | 10/28 (36%) | 36/42 (86%) | 70 (24%) |