Table 1 Basic characteristics and quality assessment of the enrolled studies
Study | Country | Type | Period | Case | Age | Sex (m/f) | Quality | |||
|---|---|---|---|---|---|---|---|---|---|---|
EH | DH | EH | DH | EH | DH | (NOS) | ||||
Buczkowski [5] | Canada | R | 1985–2004 | 10 | 10 | 51 ± 19 | 58 ± 13 | 7/3 | 8/2 | 7 |
Ou 2016 [6] | China | R | 2005–2014 | 73 | 58 | 52 (29–77) | 57 (31–81) | 59/14 | 45/13 | 8 |
Ren 2019 [7] | China | R | 2011–2016 | 17 | 27 | 53.6 (26–73) | 47.0 (18–70) | 14/3 | 22/5 | 7 |
Sun 2013 [8] | China | R | 1999–2011 | 10 | 9 | 40.8 ± 11.4 | 48.2 ± 14.2 | 2/8 | 0/9 | 6 |
Wu 2019 [9] | China | R | 2005–2015 | 30 | 100 | 41.5 ± 11.5 | 47.8 ± 11.2 | 25/5 | 89/11 | 6 |
Yang H 2014 [10] | China | R | 2003–2012 | 17 | 11 | 48.5 (23–78) | 48.5 (23–78) | NA | NA | 7 |
Yang T 2013 [11] | China | R | 2000–2009 | 28 | 115 | 49 ± 10 | 49 ± 11 | 22/6 | 105/10 | 6 |
Zhong 2016 [12] | China | R | 2004–2014 | 79 | 27 | 58.8 ± 6.8 | 58.3 ± 4.6 | 24/3 | 68/11 | 6 |
Zhou 2020 [13] | China | R(PSM) | 2012–2017 | 40 | 20 | 50% (> 60 years) | 42.5% (> 60 years) | 18/2 | 37/3 | 8 |