Table 1. Characteristics of physician-diagnosed MCS patients and gender- and age-matched controls.
| MCS patients | Controls | Odds ratio | P-valuea | |
|---|---|---|---|---|
| Female, n (%) | 90 (81.1) | 360 (81.1) | 1.00 | |
| Male, n (%) | 21 (18.9) | 84 (18.9) | ||
| Total | 111 | 444 | ||
| Age, mean (SD) | 46.4 (13.8) | 46.5 (12.7) | ||
| Age group, n (%) | ||||
| 12–29 | 9 (8.1) | 36 (8.1) | ||
| 30–39 | 23 (20.7) | 92 (20.7) | ||
| 40–49 | 40 (36) | 157 (35.4) | ||
| 50–59 | 21 (18.9) | 87 (19.6) | ||
| 60–79 | 18 (16.2) | 72 (16.2) | ||
| Education, n (%) | ||||
| Primary school | 5 (6.4) | 7 (1.8) | 2.94 (0.92–9.46) | 0.070 |
| High school | 27 (34.6) | 115 (28.8) | 0.92 (0.57–1.49) | 0.808 |
| College/University | 44 (56.4) | 248 (62.0) | 0.52 (0.34–0.79) | 0.003** |
| Graduate | 2 (2.6) | 30 (7.5) | 0.25 (0.06–1.08) | 0.042* |
| Working hours, median (IQR) | 8 (7) | 9 (3) | 0.85 (0.79–0.91) | <0.001*** |
| Occupation, n (%) | ||||
| Unemployed | 30 (29.4) | 22 (5.3) | 4.47 (2.73–7.31) | <0.001*** |
| Student | 5 (4.9) | 21 (5.0) | 0.95 (0.35–2.58) | 1.000 |
| Homeworker | 26 (25.5) | 66 (15.8) | 1.75 (1.05–2.92) | 0.045* |
| Part-time worker | 7 (6.9) | 67 (16.0) | 0.38 (0.17–0.85) | 0.013* |
| Full-time worker | 34 (33.3) | 242 (57.9) | 0.37 (0.24–0.57) | <0.001*** |
| Comorbid allergies, n (%) | ||||
| Bronchial asthma | 17 (16.7) | 5 (1.9) | 10.6 (3.8–29.6) | <0.001*** |
| Allergic rhinitis | 27 (26.5) | 11 (4.1) | 8.5 (4–17.9) | <0.001*** |
| Allergic conjunctivitis | 2 (2.0) | 2 (0.7) | 2.7 (0.4–19.3) | 0.303 |
| Rash | 9 (8.8) | 2 (0.7) | 13.0 (2.8–61.1) | <0.001*** |
| Hay fever | 27 (26.5) | 16 (5.9) | 5.7 (2.9–11.2) | <0.001*** |
| Food allergies | 15 (14.7) | 1 (0.4) | 46.4 (6–356.2) | <0.001*** |
| Other allergic symptoms | 25 (24.5) | 0 (0.0) | - | |
| Presence of existing allergy | 64 (62.7) | 32 (11.9) | 12.5 (7.3–21.6) | <0.001*** |
| Medical history, n (%) | ||||
| Atopic dermatitis | 8 (7.8) | 26 (9.6) | 0.8 (0.3–1.8) | 0.690 |
| Bronchial asthma | 11 (10.8) | 23 (8.5) | 1.3 (0.6–2.8) | 0.546 |
| Allergic rhinitis | 10 (9.8) | 48 (17.8) | 0.5 (0.2–1) | 0.077 |
| Allergic conjunctivitis | 8 (7.8) | 30 (11.1) | 0.7 (0.3–1.5) | 0.444 |
| Rash | 7 (6.9) | 39 (14.4) | 0.4 (0.2–1) | 0.052 |
| Hay fever | 11 (10.8) | 55 (20.4) | 0.5 (0.2–0.9) | 0.033* |
| Food allergies | 4 (3.9) | 16 (5.9) | 0.6 (0.2–2) | 0.608 |
| Other allergic symptoms | 9 (8.8) | 15 (5.6) | 1.6 (0.7–3.9) | 0.246 |
| Presence of previous allergy | 39 (38.2) | 131 (48.5) | 0.7 (0.4–1) | 0.081 |
aTwo-tailed Fisher's exact test for n and Wald test for median; significant at *p < 0.05, **p < 0.01, ***p < 0.001
MCS, multiple chemical sensitivity; SD, standard deviation; IQR, interquartile range