Sensitivity analysis 1: the association of pneumonia as a primary diagnosis between birth and age 20 years and multiple sclerosis diagnosed over 20 years of age
| Age group | Cases n (%) | Cont n (%) | Model 1 OR (95% CI)* | Model 2 OR (95% CI)* | Model 3 OR (95% CI)* |
| Case definition 1† | 6109 | 49 479 | |||
| Pneumonia | |||||
| 0–5 | 42 (0.69) | 378 (0.76) | 0.89 (0.65 to 1.23) | 0.89 (0.64 to 1.23) | 0.88 (0.64 to 1.22) |
| 6–10 | 14 (0.23) | 122 (0.25) | 0.92 (0.53 to 1.60) | 0.91 (0.52 to 1.58) | 0.91 (0.52 to 1.58) |
| 11–15 | 15 (0.25) | 60 (0.12) | 2.00 (1.13 to 3.53) | 2.01 (1.14 to 3.54) | 2.00 (1.13 to 3.52) |
| 16–20 | 15 (0.25) | 99 (0.2) | 1.25 (0.72 to 2.15) | 1.20 (0.70 to 2.08) | 1.18 (0.69 to 2.05) |
| IM | |||||
| 0–5 | 6 (0.1) | 21 (0.04) | 2.14 (0.86 to 5.33) | 2.15 (0.86 to 5.36) | |
| 6–10 | 9 (0.15) | 37 (0.07) | 1.90 (0.91 to 3.94) | 1.93 (0.93 to 4.01) | |
| 11–15 | 36 (0.59) | 106 (0.21) | 2.76 (1.89 to 4.04) | 2.76 (1.89 to 4.05) | |
| 16–20 | 51 (0.83) | 178 (0.36) | 2.28 (1.66 to 3.12) | 2.30 (1.68 to 3.15) | |
| Case definition 2‡ | 5592 | 43 327 | |||
| Pneumonia | |||||
| 0–5 | 37 (0.66) | 323 (0.75) | 0.88 (0.62 to 1.26) | 0.87 (0.62 to 1.24) | 0.87 (0.61 to 1.23) |
| 6–10 | 13 (0.23) | 111 (0.26) | 0.87 (0.48 to 1.58) | 0.88 (0.48 to 1.59) | 0.88 (0.48 to 1.60) |
| 11–15 | 12 (0.21) | 54 (0.12) | 1.78 (0.95 to 3.33) | 1.79 (0.96 to 3.35) | 1.78 (0.95 to 3.33) |
| 16–20 | 13 (0.23) | 85 (0.2) | 1.08 (0.58 to 2.03) | 1.04 (0.55 to 1.96) | 1.02 (0.54 to 1.93) |
| IM | |||||
| 0–5 | 5 (0.09) | 20 (0.05) | 1.57 (0.54 to 4.60) | 1.59 (0.54 to 4.67) | |
| 6–10 | 9 (0.16) | 27 (0.06) | 2.35 (1.06 to 5.18) | 2.38 (1.08 to 5.26) | |
| 11–15 | 36 (0.64) | 93 (0.21) | 2.98 (2.01 to 4.44) | 2.99 (2.01 to 4.44) | |
| 16–20 | 47 (0.84) | 150 (0.35) | 2.33 (1.66 to 3.27) | 2.35 (1.67 to 3.29) |
Bold text indicates results where the 95% CI does not cross 1.00.
*Model 1: adjusted for matching variables; model 2: adjusted for matching variables and IM; model 3: adjusted for matching variables, IM and education. In all models, the OR is comparing having a diagnosis within the age group with not having a diagnosis in the age group.
†Case definition 1: at least one MS diagnosis over age 20 years from the PR or MSR.
‡Case definition 2: two or more MS diagnoses over age 20 years from the PR or diagnosis in the MSR.
Cont, controls; IM, infectious mononucleosis; MSR, Multiple Sclerosis Register; n, total individuals in group; PR, National Patient Register.