Caffeinated beverages according to the severity of dysmenorrhoea
| Variables | Dysmenorrhoea (n (%)) | P value | ||
| No (486) | Mild (574) | Moderate-to-severe (92) | ||
| Tea | 0.216 | |||
| No | 308 (40.8) | 384 (50.9) | 62 (8.2) | |
| Yes | 178 (44.7) | 190 (47.7) | 30 (7.5) | |
| Green tea | 0.012 | |||
| No | 347 (40.2) | 443 (51.3) | 74 (8.6) | |
| Yes | 139 (48.3) | 131 (45.5) | 18 (6.3) | |
| Black tea | 0.337 | |||
| No | 413 (42.7) | 481 (49.7) | 74 (7.6) | |
| Yes | 73 (39.7) | 93 (50.5) | 18 (9.8) | |
| Oolong tea | 0.033 | |||
| No | 434 (41.3) | 528 (50.3) | 88 (8.4) | |
| Yes | 52 (51.0) | 46 (45.1) | 4 (3.9) | |
| Coffee | 0.027 | |||
| No | 275 (43.9) | 317 (50.6) | 34 (5.4) | |
| Yes | 211 (40.1) | 257 (48.9) | 58 (11.0) | |
| Soda (Coca-Cola, Pepsi) | 0.047 | |||
| No | 335 (43.7) | 381 (49.7) | 51 (6.6) | |
| Yes | 151 (39.2) | 193 (50.1) | 41 (10.6) | |
| Energy beverages | 0.050 | |||
| No | 462 (42.7) | 539 (49.8) | 81 (7.5) | |
| Yes | 24 (34.3) | 35 (50.0) | 11 (15.7) | |
P value was obtained by Kruskal-Wallis test.