Table 1.
Baseline Characteristics of MS Patients and Controls
| Characteristic | Cases (%) (n = 5565) | Controls (%) (n = 33,360) | ||
|---|---|---|---|---|
| Female | 3897 | (70.0) | 23,365 | (70.0) |
| Age at index date | ||||
| Mean | 44.8 | 44.7 | ||
| By category | ||||
| 18–29 | 670 | (12.0) | 4018 | (12.0) |
| 30–39 | 1444 | (25.9) | 8663 | (26.0) |
| 40–49 | 1617 | (29.1) | 9700 | (29.1) |
| 50–59 | 1066 | (19.2) | 6391 | (19.2) |
| 60+ | 768 | (13.8) | 4588 | (13.8) |
| Mean duration of disease (years) [95% CI] | 5.7 [5.5–5.8] | 6.0 [6.0–6.1] | ||
| Smoking | ||||
| Never | 2135 | (38.4) | 15,177 | (45.5)a |
| Current | 1543 | (27.7) | 7173 | (21.5)a |
| Ex-smoker | 815 | (14.6) | 4287 | (12.9)a |
| Unknown | 1072 | (19.3) | 6723 | (20.2) |
| BMI | ||||
| <20 | 443 | (8.0) | 1957 | (5.9)a |
| 20–25 | 1926 | (34.6) | 11,384 | (34.1) |
| 25–30 | 1318 | (23.7) | 8803 | (26.4)a |
| >30 | 888 | (16.0) | 5476 | (16.4) |
| Unknown | 990 | (17.8) | 5740 | (17.2) |
| Disease history | ||||
| Fracture | 829 | (14.9) | 4498 | (13.5)a |
| Falling | 362 | (6.5) | 995 | (3.0)a |
| Fatigue | 441 | (7.9) | 1752 | (5.3)a |
| Asthma | 582 | (10.5) | 3478 | (10.4) |
| COPD | 56 | (1.0) | 310 | (0.9) |
| Congestive heart failure | 33 | (0.6) | 157 | (0.5) |
| Diabetes mellitus | 157 | (2.8) | 854 | (2.6) |
| Rheumatoid arthritis | 34 | (0.6) | 234 | (0.7) |
| Cerebrovascular incident | 158 | (2.8) | 390 | (1.2)a |
| Epilepsy | 132 | (2.4) | 448 | (1.3)a |
| History of drug use | ||||
| Statins | 277 | (5.0) | 1278 | (3.8)a |
| Antiarrythmics | 32 | (0.6) | 163 | (0.5) |
| Antidiabetics | 130 | (2.3) | 684 | (2.1) |
| Antidepressants | 1794 | (32.2) | 7066 | (21.2)a |
| Antipsychotics | 226 | (4.1) | 953 | (2.9)a |
| Anxiolytics/hypnotics | 1187 | (21.3) | 5048 | (15.1)a |
| Anticonvulsants | 558 | (10.0) | 823 | (2.5)a |
| Opioids | 386 | (6.9) | 1217 | (3.6)a |
| Oral/intravenous glucocorticoids | 737 | (13.2) | 2132 | (6.4)a |
CI = confidence interval; BMI = body mass index; COPD = chronic obstructive pulmonary disease.
a
Statistically significant difference (p < .05) between cases and controls based on chi-square test.