A comparative study of clinical features and outcomes in young and older adults with severe acute respiratory syndrome.

Objectives: To determine the clinical presentation, findings, and outcomes of older adults (> 60) with severe acute respiratory syndrome (SARS) and compare these with a control group of younger patients (< or or =60).

Design: Retrospective cohort study.

Setting: A community-based, acute hospital in Hong Kong.

Participants: All adult inpatients with a clinical diagnosis of SARS.

Measurements: Clinical presentations, investigations, treatment, and 30- and 150-day mortality.

Results: There were 52 young and 25 older patients with a mean age +/- standard deviation of 39.5+/-11.7 and 72.1+/-7.2, respectively. Fever, chills, and diarrhea were more common in younger patients, whereas decrease in appetite and general condition occurred only in older patients. The prevalence of positive reverse-transcriptase polymerase chain reaction for SARS-associated coronavirus (SARS-CoV) in nasopharyngeal secretions and stool samples was similar in the two groups. The prevalence of positive serological tests for SARS-CoV was significantly lower in older patients (42% vs 92%, P<.001). This was largely due to incomplete testing in elderly patients. Older patients were more likely to develop secondary nosocomial infection, be admitted to an intensive care unit, and require mechanical ventilation. The cumulative 30- and 150-day mortality rates were 3.8% and 7.6%, respectively, in young patients with SARS and 56% and 60%, respectively, in older patients (P<.001).

Conclusion: Older patients with SARS more often presented with nonspecific symptoms, and the prognosis was poor. Reverse-transcriptase polymerase chain reaction was useful in diagnosing SARS in older patients, but the role of serological tests in individual elderly is limited.