Table 2. Comparison of symptoms between shift workers and the control group.
| Symptoms | Case(No.=55) No.(%) | Control(No.=38) No.(%) | Chi-Square | p value |
| Abdominal cramps | 31 (56.4) | 11 (28.9) | 6.82 | 0.009 |
| Joint or muscle pain | 23 (41.8) | 8 (21) | 4.36 | 0.037 |
| Bloating or weight gain | 21 (38.2) | 6 (15.8) | 5.46 | 0.019 |
| Breast tenderness | 24 (43.6) | 6 (15.7) | 7.97 | 0.005 |
| Change in appetite | 20 (36.4) | 5 (13.2) | 6.15 | 0.013 |
| Change in sleep pattern | 25 (45.4) | 6 (15.7) | 8.90 | 0.003 |
| Difficulty in concentrating | 19 (34.5) | 4 (10.5) | 6.96 | 0.008 |
| Decreased energy (fatigue) | 39 (70.9) | 14 (36.8) | 10.64 | 0.001 |
| Decreased interest in activity | 33 (60) | 13 (34.2) | 5.97 | 0.014 |
| Mood swing | 32 (58.1) | 15 (39.4) | 3.1 | 0.076 |
| Anxiety and/or tension | 23 (41.8) | 16 (42.1) | 0.001 | 0.970 |
| Anger and/or irritability | 36 (65.4) | 16 (42.1) | 4.97 | 0.026 |
| Depressed or low mood | 27 (49.1) | 12 (31.5) | 2.83 | 0.092 |
| PMSa | 31 (56.4) | 12 (31.5) | 5.55 | 0.018 |
| PMDDb | 12 (21.8) | 5 (13.2) | 1.12 | 0.280 |
| No PMS or PMDD | 12 (21.8) | 21 (55.2) | 10.98 | 0.001 |
a PMS: Premenstrual syndrome
b PMDD: Premenstrual dysphoric disorder