HRs comparing the rates of hospitalisation listing influenza and death listing influenza (during 2015/2016–2018/2019 influenza seasons) in patients with inflammatory joint diseases receiving csDMARDs to patients receiving bDMARDs/tsDMARDs in Sweden
| Outcome | Cohort | Events (n) | Absolute risk (%) | HR 1 (95% CI)* | HR 2 (95% CI)† | HR 2 COVID-19 (95% CI)‡ |
| Hospitalisation | csDMARD | 327 | 0.3 | 1 (ref) | 1 (ref) | 1 (ref) |
| TNFi | 110 | 0.2 | 0.54 (0.43 to 0.66) | 1.18 (0.92 to 1.52) | 1.05 (0.67 to 1.64) | |
| Abatacept | 25 | 0.6 | 2.05 (1.33 to 3.16) | 2.01 (1.26 to 3.19) | 0.49 (0.15 to 1.59) | |
| Tocilizumab | 9 | 0.2 | 0.74 (0.38 to 1.43) | 1.28 (0.65 to 2.51) | – | |
| Rituximab | 42 | 0.5 | 1.83 (1.33 to 2.52) | 1.49 (1.04 to 2.14) | 1.03 (0.58 to 1.81) | |
| All bDMARDs/tsDMARDs combined§ | 191 | 0.2 | 0.75 (0.62 to 0.89) | 1.32 (1.06 to 1.64) | 1.08 (0.73 to 1.58) | |
| Death | csDMARD | 21 | 0.02 | 1 (ref) | 1 (ref) | 1 (ref) |
| TNFi | 3 | 0.004 | – | – | 1.03 (0.40 to 2.61) | |
| Abatacept | 1 | 0.02 | – | – | – | |
| Tocilizumab | 0 | 0 | – | – | – | |
| Rituximab | 1 | 0.01 | – | – | 3.20 (1.19 to 8.57) | |
| All bDMARDs/tsDMARDs combined§ | 5 | 0.006 | 0.30 (0.11 to 0.81) | 0.65 (0.04 to 12.00) | 1.26 (0.60 to 2.64) |
Note: Results only presented where treatment cohorts have five or more events.
Previously published corresponding HRs for COVID-19 are in the rightmost column.
*Adjusted for influenza season; age, sex and region accounted for via matching.
†Additionally adjusted for disease duration, Disease Activity Score on 28 joints, number of previous bDMARDs/tsDMARDs and concomitant steroid use, socioeconomic factors (education, civil status and country of birth), influenza hospitalisation in the previous year and comorbidities (history of the following diseases: cancer, diabetes, heart failure, ischaemic heart disease, lung disease, stroke, surgery, venous thrombotic event and kidney failure).
‡Taken from the COVID analyses presented in Bower et al,11 adjusted for the same factors as †, but via inverse probability treatment weighting via propensity score estimation.
§Includes Janus kinase inhibitors.
bDMARD, biological disease-modifying antirheumatic drug; csDMARD, conventional synthetic disease-modifying antirheumatic drug; ref, reference; TNFi, tumour necrosis factor inhibitor; tsDMARD, targeted synthetic disease-modifying antirheumatic drug.