Table 2.
Risk of multiple sclerosis by categories of tuberculin skin test reactivity
| TST category | Participants | Multiple sclerosis | Person-years | Age-adjusteda HR (95% CI) | Multivariable adjustedb HR (95% CI) |
|---|---|---|---|---|---|
| HR per 4-mm increment in infiltrate size | 279 889 | 679 | 13 776 184 | 0.83 (0.75–0.93) | 0.86 (0.76–0.96) |
| Quantiles of distributionc | |||||
| First quartile | 83 756 | 233 | 4 165 549 | 0.99 (0.81–1.20) | 0.95 (0.78–1.15) |
| Second quartile | 67 159 | 182 | 3 317 245 | Reference | |
| Third quartile | 73 392 | 178 | 3 588 191 | 0.95 (0.78–1.17) | 0.95 (0.78–1.17) |
| Fourth quartile | 55 584 | 86 | 2 705 200 | 0.65 (0.50–0.84) | 0.65 (0.50–0.85) |
a
Adjusted for age at TST and age at BCG.
b
Multivariate adjusted for sex, age at BCG, age at TST, birth year, county of residence and BMI.
c
First quartile: 0–4 mm; second quartile: 5–6 mm; third quartile: 7–8 mm; fourth quartile: 9–50 mm.
TST, tuberculin skin test; BCG, Bacillus Calmette–Guérin; HR, hazard ratio.