Table 2. Association of Influenza With Parkinson Disease (PD) by Time Since Infection Among Individuals With PD Identified in Denmark, January 2000 to December 2016.
| Measure | No. | OR (95% CI) | P value for adjusted model | ||
|---|---|---|---|---|---|
| Patients with PD | Controls | Unadjusted | Adjusteda | ||
| Influenza-specific codes during any calendar time | |||||
| Unexposed | 10 231 | 51 196 | 1 [Reference] | 1 [Reference] | NA |
| Ever infected prior to PD | 40 | 159 | 1.26 (0.89-1.78) | 1.28 (0.91-1.82) | .16 |
| ≤5 y | <10 | 52 | 0.87 (0.43-1.76) | 0.89 (0.44-1.80) | .74 |
| >5-10 y | <10 | 31 | 0.81 (0.31-2.07) | 0.84 (0.33-2.16) | .72 |
| >10 y | 26 | 76 | 1.71 (1.10-2.67) | 1.73 (1.11-2.71) | .02 |
| >10-15 yb | 6 | 23 | 1.30 (0.53-3.20) | 1.33 (0.54-3.27) | .53 |
| >15 yb | 20 | 53 | 1.89 (1.13-3.16) | 1.91 (1.14-3.19) | .01 |
| Influenza-specific codes during peak influenza activity | |||||
| Unexposed | 10 246 | 51 249 | 1 [Reference] | 1 [Reference] | NA |
| Ever infected prior to PD | 25 | 106 | 1.18 (0.76-1.82) | 1.22 (0.79-1.88) | .38 |
| ≤5 y | 8 | 37 | 1.08 (0.50-2.32) | 1.10 (0.51-2.37) | .81 |
| >5-10 y | 5 | 28 | 0.89 (0.34-2.31) | 0.93 (0.36-2.41) | .88 |
| >10 yc | 12 | 41 | 1.46 (0.77-2.78) | 1.52 (0.80-2.89) | .21 |
Abbreviations: NA, not applicable; OR, odds ratio.
a
Adjusted models are adjusted for cardiovascular disease, diabetes, chronic obstructive pulmonary disease, emphysema, lung cancer, Crohn disease, and ulcerative colitis.
b
Individuals in these categories are included in the more than 10 years category.
c
Stratified results for more than 10 to 15 years and more than 15 years are not shown because numbers and results are suppressed for cells where small counts would enable calculation of numbers less than 5.