Introduction
Methods
Literature sources and search strategy
Inclusion criteria
Data extraction and quality assessment
Data analysis
Results
Search results
Basic characteristics of the included studies and risk of bias assessment
Source | Year | Study year | Study design | No. of patients | No. of myasthenic crisis cases | Age at thymectomy (mean) Age, years | Gender Male/women | Study region | Non-thymomatous/thymoma | Significant risk factors | NOS score |
---|---|---|---|---|---|---|---|---|---|---|---|
Kato | 2019 | 2000–2015 | retrospective cohort study | 90 | 14 | median (range) 51.5 (41.3–64.0) | 41/46 | Japan | 33/57 | (15) | 8 |
Xue | 2017 | 2005–2014 | case-control studies | 127 | 13 | NA | 68/59 | china | 127 | (3),(10) | 8 |
Zou | 2016 | 2007.06–2013.12 | retrospective cohort study | 541 | 67 | 26.4 ± 11.7/27.06 ± 13.5 | 256/285 | china | NA | (1),(4),(6),(16) | 6 |
Ando | 2015 | 2000.01–2013.12 | case-control studies | 55 | 10 | median (range) 55 (13–79) | 25/30 | Japan | 30/25 | (1),(17) | 7 |
Lee | 2015 | 2007.10–2012.03 | case-control studies | 146 | 10 | T/C 25.0 (15.5–48.0)/35.0 (27.0–46.0) | NA | Korea | 105/41 | (12),(18) | 8 |
Li | 2018 | 2000.01–2013.03 | case-control studies | 176 | 51 | 46.6 ± 11.7 | 90/83 | China | 0/173 | (2),(19) | 9 |
Yu | 2014 | 1997.03–2012.03 | retrospective cohort study | 178 | 58 | 38.4 ± 13.2 | 95/83 | China | 69/109 | (1),(2),(8) | 8 |
Choi | 2014 | 1996.01–2009.12 | retrospective cohort study | 49 | 12 | 50.3 ± 12.4 | 23/25 | Korea | 0/49 | (12) | 6 |
Leuzzi | 2014 | 1995.01–2011.12 | case-control studies | 177 | 22 | 45.8 ± 16.8 | 107/70 | Italy | 53/124 | (1),(3),(4),(14) | 9 |
Nam | 2011 | 1997.01–2007.12 | retrospective cohort study | 68 | 20 | age at onset 43.6 ± 13.9 | NA | Japan | 28/38 | (1) | 9 |
Chu | 2011 | 1990–2009 | case-control studies | 243 | 44 | 31.5 ± 15.7 | 124/119 | China | 175/68 | (3),(5),(13) | 5 |
Liu | 2006 | 1990.01–2006.01 | case-control studies | 176 | 36 | 31 ± 14 | 74/102 | China | 122/54 | (1),(2),(6),(24) | 9 |
Li | 2016 | 1970.05–2011.05 | case-control studies | 306 | 49 | 31.54 ± 16.37 | 155/151 | China | NA | (1),(2),(5) | 8 |
Qian | 2016 | 2002.02–2015.06 | case-control studies | 86 | 16 | median (range)47 (25–71) | 37/49 | China | 40/46 | (1),(2),(3) | 8 |
Li | 2017 | 2008.01 ~ 2015.01 | case-control studies | 63 | 12 | median (range)37 (10–76) | 25/38 | China | 41/22 | (3),(8),(9),(10) | 7 |
Liu | 2014 | 2011.01–2014.02 | case-control studies | 102 | 42 | T/C 46.7 ± 10.11/39.6 ± 6.41 | 45/57 | China | 36/66 | (3),(5),(11),(12),(20) | 6 |
Niu | 2013 | 2002.07–2012.07 | case-control studies | 134 | 28 | age at onset 35 (1–82) | 66/68 | China | 69/65 | (3) | 6 |
Ma | 2011 | 1995.07–2009.12 | case-control studies | 84 | 24 | median (range)42.67 (16—68) | 35/49 | China | 21/63 | (1),(3),(8),(11) | 6 |
Zhang | 2015 | 2008.06–2014.06 | case-control studies | 58 | 15 | T/C 60.60 ± 6.20/60.7 ± 6.3 | 26/32 | China | 0/58 | (3),(11),(21) | 6 |
Wang | 2006 | NA | case-control studies | 126 | 13 | median (range)38 (9–62) | 54/72 | China | 56/70 | (1),(3),(7),(22) | 5 |
Chen | 2007 | 2002.07–2005.12 | case-control studies | 101 | 29 | 33.2 ± 14.67 | 43/58 | China | 33/68 | (1),(3),(4),(13),(23) | 8 |
Ge | 2019 | 2008.01–2018.01 | retrospective cohort study | 47 | 14 | 40.1 ± 16.7 | 22/25 | China | 24/23 | (11),(13) | 6 |
Li | 2014 | 2008.01–2013.06 | case-control studies | 198 | 32 | NA | NA | China | 135/63 | (1),(3),(5),(6) | 5 |
Kanai | 2017 | 2002.01–2014.12 | case-control studies | 275 | 17 | T/C:45.8 ± 16.1/49.2 ± 15.5 | 106/169 | Japan | 145/130 | (2),(12),(14) | 9 |
Watanabe | 2004 | 1985.01–2002.12 | retrospective cohort study | 122 | 44 | 44 ± 17 | 30/92 | Japan | 93/29 | (2),(7),(9) | 6 |
Significant Risk Factors | No. of studies | No. of MC | No. of total patients | Analysis model | Adjusted OR (95%CI) | Study heterogeneity | Test for overall effect | Begg’s test P value | ||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Q | P | I2,% | Z | P value | ||||||||
Preoperative patient condition-related risk factors | ||||||||||||
Preoperative MC history | 12 | 377 | 2094 | Fixed | 4.13 [3.08, 5.54] | 13.46 | 0.26 | 18 | 9.46 | <0.00001 | 0.034 | |
without | ref | |||||||||||
with | ||||||||||||
Preoperative bulbar symptoms | 8 | 254 | 1443 | Fixed | 3.71 [2.54, 5.42] | 7.55 | 0.37 | 7 | 6.76 | <0.00001 | 0.174 | |
without | ref | |||||||||||
with | ||||||||||||
Preoperative Osserman stages | 10 | 358 | 2040 | Fixed | 4.55 [3.23, 6.13] | 30.74 | 0.0006 | 67 | 9.15 | <0.00001 | 0.64 | |
I | ref | |||||||||||
IIa + IIb + III + VI | 2 | 2.57 [1.43,4.61] | 0.01 | 0.94 | 0 | 3.16 | 0.002 | |||||
IIb + III + VI | 8 | 11.15 [6.88,18.08] | 5.41 | 0.61 | 0 | 9.78 | <0.00001 | |||||
VI + V | 1 | 1.80 [0.96, 3.36] | NA | NA | NA | 1.84 | 0.002 | |||||
Postoperative lung infection | 5 | 92 | 448 | Fixed | 6.49 [2.64, 15.98] | 2.39 | 0.5 | 0 | 4.07 | <0.00001 | 0.624 | |
without | ref | |||||||||||
with | ||||||||||||
Thymoma | 5 | 234 | 1390 | Fixed | 2.96 [2.13, 4.13] | 3.63 | 0.3 | 17 | 6.43 | <0.00001 | 0.806 | |
no | ref | |||||||||||
yes | ||||||||||||
Preoperative dosage of pyridostigmine bromide | 4 | 193 | 1103 | Fixed | 3.53 [2.47,5.03] | 4.98 | 0.17 | 40 | 6.94 | <0.00001 | 1 | |
≥240 mg | ||||||||||||
<240 mg | ref | |||||||||||
Preoperative serum AchR-Ab level (nm/L) | 2 | 27 | 248 | Fixed | 8.74 [3.31, 23.08] | 0.03 | 0.87 | 0 | 3.65 | 0.0003 | 1 | |
>100 | ||||||||||||
≤100 | ref | |||||||||||
Operation time | 3 | 95 | 325 | Random | 1.18 [0.89, 1.57] | 19.47 | <0.00001 | 90 | 1.13 | 0.26 | 0.296 | |
Surgery-related risk factors | ||||||||||||
Intraoperative blood loss > 1000 ml | 2 | 26 | 185 | Fixed | 15.03 [3.50, 64.50] | 0.03 | 0.87 | 0 | 3.65 | 0.0003 | 1 | |
>1000 ml | ||||||||||||
≤1000 ml | ref | |||||||||||
WHO classification | 2 | 25 | 190 | Fixed | 15.23 [4.63, 50.13] | 0.22 | 0.64 | 0 | 4.48 | <0.00001 | 1 | |
non-thymoma and non-invasive thymoma | ref | |||||||||||
invasive thymoma | ||||||||||||
Mode of operation | 4 | 66 | 252 | Fixed | 5.88 [2.06,16.80] | 2.09 | 0.55 | 0 | 3.3 | 0.001 | 0.089 | |
video-assisted thoracoscopy | ref | |||||||||||
thoracotomy | ||||||||||||
Postoperative risk factors | ||||||||||||
Preoperative lung function | 5 | 110 | 784 | Fixed | 5.71 [3.11, 10.48] | 3.3 | 0.51 | 0 | 5.62 | <0.00001 | 1 | |
normal | ref | |||||||||||
abnormal | ||||||||||||
Major postoperative complications | 3 | 87 | 391 | Fixed | 33.78 [10.57,107.96] | 1.59 | 0.45 | 0 | 5.94 | <0.00001 | 1 | |
without | ref | |||||||||||
with | ||||||||||||
Disease duration before thymectomy | 2 | 39 | 452 | Fixed | 5.45 [1.96, 15.14] | 0.02 | 0.9 | 0 | 3.26 | 0.001 | 1 | |
1983 | 11,345 |