Table 4.
Quality assessment of single-arm studies
| Study, year [ref.] | Representativenessa | Selection of non- exposedb |
Ascertainment of exposurec |
Incident diseased |
Compa rabilitye |
Assessment of outcomef |
Length of follow- upg |
Adequacy of follow- uph |
|---|---|---|---|---|---|---|---|---|
| Jiakai Li, 2013 [11] | B | C | A | A | C | B | A | B |
| Bin Huo, 2017 [12] | A | C | A | A | C | B | A | B |
| Jingkui Yang, 2014 [13] | A | C | A | A | C | B | A | D |
| Mingyao Ke, 2011 [14] | A | C | A | A | C | B | A | A |
| Jingkui Yang, 2014 [20] | A | C | A | A | C | B | A | D |
| Hua Cheng, 2019 [21] | A | C | A | A | C | B | A | A |
A: truly representative, B: somewhat representative, C: selected group, D: no description of the derivation of the cohort, b A: drawn from the same community as the exposed, B: drawn from a different source, C: no description of the derivation of the non-exposed, c A: secure record, B: structured interview, C: written self-report, D: no description, d Demonstration that the outcome of interest was not present at start of study: A yes, B: no, e A: study controls for demographics/comorbidities, B: study controls for any additional factor (e.g., age, severity of illness), C: not done; f A: independent or blind assessment, B: record linkage, C: self-report, D: no description, g Long enough for outcomes to occur? A: yes, B: no, h A: complete follow-up, B: subjects lost to follow-up was unlikely to introduce bias, C: follow-up rate of 90% or lower, D: no statement