Table 1.
Bias assessment.
| Study | NIH Criteria | ||||
|---|---|---|---|---|---|
| Hu et al., 1999 [22] | Praagman et al., 2016 [32] | Praagman et al., 2016 [31] | Zong et al., 2016 [33] | Praagman et al., 2019 [30] | |
| Yes | Yes | Yes | Yes | Yes | (1) Clear objective research questions |
| Yes | Yes | Yes | Yes | Yes | (2) Defined study population |
| Yes | Yes | Yes | Yes | Yes | (3) Participant of >50% of eligible persons |
| Yes | Yes | Yes | Yes | No | (4) Consistent subject selection/recreation and predetermined exclusion/inclusion criteria applied |
| NR/UTD | NR/UTD | NR/UTD | NR/UTD | NR/UTD | (5) Sample size justification/stats provided |
| Yes | Yes | Yes | Yes | Yes | (6) Exposures measured prior to outcome |
| Yes | Yes | Yes | Yes | Yes | (7) Appropriate timeframe to assess desired exposure and outcome |
| Yes | Yes | Yes | Yes | Yes | (8) For variable exposures, different levels were assessed |
| Yes | Yes | Yes | Yes | Yes | (9) Clearly defined independent variable consistently implemented |
| Yes | No | No | Yes | No | (10) Repeat measure of exposure over time |
| Yes | Yes | Yes | Yes | No | (11) Clearly defined dependent variables consistently implemented |
| Yes | NR/UTD | NR/UTD | Yes | Yes | (12) Blinded outcome assessors |
| NR/UTD | NR/UTD | NR/UTD | NR/UTD | No | (13) Loss to follow up < 20% |
| Yes | Yes | Yes | Yes | No | (14) Confounding variables identified and adjusted statistically |
Table created using Study Quality Assessment Tools | NHLBI, NIH. https://www.ncbi.nlm.nih.gov/pubmed/NR/UTD (Accessed on 12 October 2022), not reported or unable to determine.