Death rate and risk factors found
Data on 3,729 COVID-19 cases in people with RMDs were included in the current analysis, all recorded in the first few months of the registry being open and up until July 1, 2020. In all, 390 (10.5%) of people died. While this is “clearly higher” than reported in the general population in most countries, the analysis was not designed to calculate a precise estimate.
“It should not be taken as an estimate of the overall death rate among patients with rheumatic diseases and COVID-19,” Dr. Machado and coauthors have been keen to point out.
“Age is always the biggest risk factor,” Dr. Machado explained. “There’s always a gradient: the older the patient, the worse the outcome.”
Indeed, there was a threefold increased risk for death among those aged 66-75 years versus those who were 65 years or younger (odds ratio, 3.00), and a sixfold increased risk for patients older than 75, compared with the younger age group (OR, 6.18).
Having both hypertension and cardiovascular disease was associated with an OR of 1.89, and coexisting chronic lung disease also significantly increased the chances of dying from COVID-19 (OR, 1.68).
Being of male sex was associated with a 46% increased risk for death from COVID-19 versus being of female sex.
The risk for COVID-19 death also rose with the use of corticosteroids. Compared with no steroid use, there was a 69% increased risk for with death at doses of 10 mg or more prednisolone equivalent per day.
“The finding about moderate to high doses of steroids being associated with a worse outcome is consistent with the first report; it was the same for hospitalization,” Dr. Machado observed.
The general consensus on steroid use in the COVID-19 setting is that they should be continued as needed, but at the lowest possible dose, as outlined in provisional recommendations set out by the recently renamed European Alliance of Associations for Rheumatology.
The GRA physician registry findings provide further support for this, suggesting that disease control should be optimized with disease-modifying antirheumatic drugs, ideally without increasing the dose of steroids.
Surprise over sulfasalazine risk
“Taking all medications into account – such as methotrexate, leflunomide, hydroxychloroquine, [tumor necrosis factor] blockers, interleukin-6 blockers, and [Janus kinase] inhibitors – it is quite reassuring because we did not see an association with worse outcome with those drugs overall,” Dr. Machado said.
However, treatment with rituximab (OR, 4.0), sulfasalazine (OR, 3.6), and immunosuppressive agents such as azathioprine, cyclophosphamide, cyclosporine, mycophenolate, or tacrolimus (OR, 2.2), were associated with higher odds of dying from COVID-19 when compared with treatment with methotrexate alone.
The findings for rituximab and immunosuppressant use were perhaps not unexpected, but the possible association between sulfasalazine and COVID-19 death was “a bit intriguing,” Dr. Machado observed. “Sulfasalazine is believed to have low immunosuppressive effect.”
This warrants further investigation, but there are likely a range of confounding factors at play. One could be that people considered to be at higher risk may have been more often prescribed sulfasalazine because it was thought to be less immunosuppressive. Another might be because people taking sulfasalazine were more likely to be smokers, and they were also not advised to protect themselves from exposure to the virus (shielding) during the first wave of the pandemic, at least not in the United Kingdom.