TABLE 1.
Quality assessment for studies.
| The cochrane Collaboration’s tool for assessing randomized controlled trials | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Author/year/country | Selection bias | Performance bias | Detection bias | Attrition bias | Reporting bias | Other bias | |||||||||
| Theilmann et al. (1994) Germany | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | |||||||||
| Sauer et al. (1996) Germany | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | |||||||||
| Siegerstetter et al. (1997) Germany | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | |||||||||
| Wang et al. (2016) China | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | |||||||||
| Lv et al. (2018) China | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | |||||||||
| The Agency for Healthcare Research and Quality scoring table for cohort studies | |||||||||||||||
| Author/year/country | Representativeness of the exposed cohort | Selection of the non-exposed cohort | Ascertainment of exposure | Demonstration that outcome of interest was not present at the start of the study | Comparability between exposed and non-exposed cohort | Assessment of outcome | Was follow-up long enough for outcomes to occur | Adequacy of follow-up of cohorts |
Total
Score |
||||||
| Tang et al. (2017) China | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 7 | ||||||
| Zhang et al. (2020) China | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 | ||||||
| Lv et al. (2021) China | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 | ||||||
| Han et al. (2011) China | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 7 | ||||||
| Wang et al. (2015) China | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 7 | ||||||
| Wan et al. (2017) China | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 7 | ||||||
| Seifert et al. (2022) Germany | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 | ||||||