Response to: 'Incidence of severe COVID-19 in a Spanish cohort of 1037 patients with rheumatic diseases treated with biologics and JAK-inhibitors' by Jovani et al

We appreciate the comments by Jovani et al 1 in response to our manuscript evaluating the outcomes among a cohort of patients with rheumatic diseases and COVID-19.2 We commend the authors for sharing the experience of their patients during the COVID-19 pandemic and would like to reply to some of the queries they posed to us.\n\nFirst, Jovani et al wondered why we included age in our multivariable models if we matched on age. This was done because continuous age was matched over a range (±5 years). To further address any potential differences in ages between the study groups (which was minimal), we included age in our multivariable models. Notably, adjusting for age did not change our findings when comparing adjusted to unadjusted models.\n\nSecond, the authors questioned why lymphopaenia and troponin levels were not included in the multivariable models. These laboratory changes may be a result of infection that occurred after the exposure of interest (COVID-19 infection). As such, they should not be adjusted for in models because they may be on the causal pathway between the exposure and outcome (eg, mechanical ventilation …