Table 2.
Risk of bias was assessed using the Newcastle–Ottawa scale. A higher overall score indicates a lower risk of bias; a score of 5 or less (out of 9) corresponds to a high risk of bias
| Study | Selection | Comparability | Outcome | Total score | AHRQ standards |
|---|---|---|---|---|---|
| 1997, Xenakis | *** | * | *** | 7 | Good |
| 1999, Ortiguera | *** | ** | ** | 7 | Good |
| 2006, Mont | *** | ** | *** | 8 | Good |
| 2008, Dastane | ** | ** | *** | 7 | Fair |
| 2009, Radl | *** | * | *** | 7 | Good |
| 2014, Bergh | *** | * | ** | 6 | Good |
| 2016, Ancelin | **** | * | *** | 8 | Good |
| 2016, Liu | *** | ** | *** | 8 | Good |
| 2017, Singh | **** | ** | ** | 8 | Good |
| 2018, Osawa | *** | * | *** | 7 | Good |
| 2019, Hart | *** | ** | ** | 7 | Good |
| 2020, Kumar | *** | * | ** | 6 | Good |
| 2021, Sax | *** | * | * | 5 | Fair |
| 2022, Moharrami | *** | * | ** | 6 | Good |