Two new US studies identify risk factors for COVID-19 death, one pointing to the use of certain medications and the other describing development of a risk calculator that showed elevated risk in non-white populations and in people with underlying conditions and social deprivation.Hydroxychloroquine, azithromycin comboThe first study, published yesterday in JAMA Network Open, found that use of a combination of the antimalarial drug hydroxychloroquine and the antibiotic azithromycin was linked to increased risk of death in hospitalized COVID-19 patients, while cholesterol-lowering statin drugs, vitamin C or D, and the cardiovascular drugs angiotensin-converting enzyme (ACE) inhibitors and calcium channel blockers appeared protective.A