Table 2 Results of quality assessment of cohort studies.
Study ID | Qiao 2019 | Chen 2019 | Wan 2021 | Yang 2022 | ||
|---|---|---|---|---|---|---|
Selection | Representativeness of exposed cohort | a) Truly representative of average condition in community b) Somewhat representative of average condition in community c) Selected group of users, e.g., nurses, volunteers d) No description of derivation of cohort | b) | b) | b) | b) |
Selection of non-exposed cohort | a) Drawn from same community as exposed cohort b) Drawn from different source c) No description of derivation of non-exposed cohort | a) | a) | a) | a) | |
Ascertainment of exposure | a) Secure records (e.g., surgical records) b) Structured interview c) Written self-report d) No description | a) | a) | a) | a) | |
Demonstration that outcome of interest not present at start of study | a) Yes b) No | a) | b) | b) | b) | |
Comparability | Comparability of cases and controls on basis of design or analysis | a) Study controls for age b) Study controls for any additional factor | a) | a) | a) | b) |
Outcome | Assessment of outcome | a) Independent blind assessment b) Record linkage c) Self-report d) No description | b) | b) | b) | b) |
Was follow-up long enough for outcomes to occur? | a) Yes b) No | a) | a) | a) | a) | |
Adequacy of follow-up of cohorts | a) Complete follow-up: all subjects accounted for b) Small number (< 20%) lost to follow-up, unlikely to introduce bias, or description provided of those lost c) Follow-up rate > 20% and no description of those lost d) No statement | b) | a) | a) | a) | |
Total | 9 | 8 | 8 | 8 | ||
