LAUSR

OBJECTIVES The Lessening Organ Dysfunction with Vitamin C trial showed a harmful effect of vitamin C on 28-day death or persistent organ dysfunction. To maximize interpretation, we present a post hoc Bayesian reanalysis. DESIGN Bayesian reanalysis of a randomized placebo-controlled trial. SETTING Thirty-five ICUs. PATIENTS Adults with proven or suspected infection, vasopressor support, and no more than 24 hours of ICU admission. INTERVENTIONS Patients were allocated to receive either vitamin C (50 mg/kg of body weight) or placebo every 6 hours for up to 96 hours. MEASUREMENTS AND MAIN RESULTS The primary outcome was the composite of death or persistent organ dysfunction (i.e., vasopressor use, invasive mechanical ventilation, or new renal replacement therapy) at 28 days. We used Bayesian log-binomial models with random effects for hospital site and varying informative prior beliefs for the effect of vitamin C to estimate risk ratios (RRs) with 95% credible intervals (Crls) in the intention to treat population (vitamin C, 435 patients; placebo, 437 patients). Using weakly neutral priors, patients allocated to vitamin C had a higher risk of death or persistent organ dysfunction at 28 days (RR, 1.20; 95% Crl, 1.04-1.39; probability of harm, 99%). This effect was consistent when using optimistic (RR, 1.14; 95% Crl, 1.00-1.31; probability of harm, 98%) and empiric (RR, 1.09; 95% Crl, 0.97-1.22; probability of harm, 92%) priors. Patients allocated to vitamin C also had a higher risk of death at 28 days under weakly neutral (RR, 1.17; 95% Crl, 0.98-1.40; probability of harm, 96%), optimistic (RR, 1.10; 95% Crl, 0.94-1.30; probability of harm, 88%), and empiric (RR, 1.05; 95% Crl, 0.92-1.19; probability of harm, 76%) priors. CONCLUSIONS The use of vitamin C in adult patients with proven or suspected infection and vasopressor support is associated with high probability of harm.