Table 1.
Baseline characteristics of include studies and methodological assessment
| Authors | Study periods | Country | Study design | Patients（n）ultrasonic/clamp crushing | Level of evidence | Quality score |
|---|---|---|---|---|---|---|
| Ahmad | 2015-2016 | Egypt | Randomized Controlled Trial | 36/36 | A | 6 |
| Bon N. Koo | 2003 | Korea | Randomized Controlled Trial | 25/25 | A | 7 |
| H. G. Rau | 1990-1993 | Germany | Randomized Controlled Trial | 28/61 | A | 5 |
| Doklestić | 2008-2010 | Serbia | Randomized Controlled Triall | 20/20 | A | 7 |
| Luca | 2002-2004 | Italy | Comparative | 100/100 | C | 5 |
| Lesurtel | 2003-2004 | Switzerland | Prospective | 25/25 | C | 6 |
| Nanashima | 2005-2012 | Japan | Retrospective | 24/118 | B | 7 |
| Gotohda | 2011-2012 | Japan | Randomized Controlled Trial | 107/104 | A | 7 |
| Qiao | 2008-2010 | China | Randomized Controlled Trial | 17/20 | A | 6 |
| S.-T. FAN | 1989-1994 | China | Prospective | 69/96 | B | 7 |
| Sun | 2012 | China | Prospective | 80/80 | B | 7 |
| Tadatoshi | 1998-1999 | Japan | Randomized Controlled Trial | 66/66 | A | 7 |
| Zhu | 2013-2018 | China | Retrospective | 33/29 | B | 7 |