Outcomes and prognostic factors in 267 patients with severe acute respiratory syndrome in Hong Kong

Background: severe acute respiratory syndrome (SARS) has become a global public health emergency. Objective: To evaluate the characteristics and outcomes of patients with SARS in Hong Kong and to identify predictors of mortality. Design: Retrospective cohort study. Setting: Quarantine hospital for patients with SARS in Hong Kong. Patients: 267 consecutive patients hospitalized from 26 February to 31 March 2003 for probable or confirmed SARS. Measurements: Clinical, laboratory, and radiographic measures; 3-month mortality rate. Results: According to our case definition, there were 227 cases of confirmed SARS and 40 cases of probable SARS. Common presenting symptoms were fever (99% of patients), chills (74%), malaise (63%), and myalgia (50%). Laboratory findings included lymphopenia (73%), thrombocytopenia (50%), hyponatremia (60%), and elevated levels of lactate dehydrogenase (47%) and C-reactive protein (75%). During hospitalization, incidence of diarrhea (53%), anemia (53%), and acute renal failure (6%) increased. Sixty-nine patients (26%) required intensive care because of respiratory failure. The 3-month mortality rate was 12% (95% Cl, 8% to 16%). Factors contributing to mortality were respiratory failure, acute renal failure, and nosocomial sepsis. On multivariate Cox regression, age older than 60 years (relative risk, 5.10 [Cl, 2.30 to 11.31]; P < 0.001) and lactate dehydrogenase level greater than 3.8 mu kat/L at presentation (relative risk, 2.20 [Cl, 1.03 to 4.71]; P = 0.04) were independent predictors of mortality. Conclusion: Because of the longer follow-up period in our cohort, the mortality rate in these patients is higher than rates reported in previous studies. Advanced age and high lactate dehydrogenase level at presentation predict mortality.