Table 1 The incidence of MSDs among coal miners with different demographic characteristics [n (%)]
|  | Group | Number | MSDs(%) | χ2 | P |
|---|---|---|---|---|---|
Sex | Male | 1471 | 799 (54.3) | 25.565 | < 0.001 |
Female | 204 | 149 (73.0) | |||
Age group, years | < 30 | 291 | 99 (34.0) | 96.464 | < 0.001 |
30–39 | 464 | 259 (55.8) | |||
40–49 | 667 | 402 (60.3) | |||
50–60 | 253 | 188 (74.3) | |||
Working years | < 5 | 475 | 206 (43.4) | 80.432 | < 0.001 |
5–15 | 649 | 352 (54.2) | |||
> 15 | 551 | 390 (70.8) | |||
Shift | Fixed day shift | 477 | 239 (50.1) | 25.159 | < 0.001 |
Two shifts | 538 | 350 (65.1) | |||
Four shifts | 660 | 359 (54.4) | |||
Type of work | Coal miner | 330 | 225 (68.2) | 107.562 | < 0.001 |
Heading driver | 329 | 144 (43.8) | |||
Transport worker | 304 | 114 (37.5) | |||
Move the frame worker | 300 | 192 (64.0) | |||
Safety supervisor | 412 | 273 (66.3) | |||
Marital status | Single | 282 | 167 (59.2) | 0.950 | 0.330 |
Married | 1393 | 781 (56.1) | |||
Educational level | Junior High school and below | 1004 | 648 (64.5) | 86.299 | < 0.001 |
High school | 300 | 164 (54.7) | |||
Junior College and above | 371 | 136 (36.7) | |||
Monthly income, yuan | ≤5000 | 531 | 340 (64.0) | 42.512 | < 0.001 |
5001–6500 | 415 | 248 (59.8) | |||
6501–8000 | 490 | 265 (54.1) | |||
>8001 | 239 | 95 (39.7) |