Abstract: The objective was to study the effects of underling diseases on the prognosis in patients with severe acute respiratory syndrome(SARS).All the 212 patients admitted to Xuanwu hospital from May to June in 2003 were studied retrospectively.The mortality in patients with underling diseases(20.7%)was significantly higher than patients without underlying diseases(4.5%).There was a higher mortality in patients with or above two underling diseases.By Logistic regression,among diabetes mellitus(DM),hypertension,coronary heart disease,chronic obstructive pulmonary disease(COPD),cerebral vessel disease(CVD)and hepatitis/hepatocirrhosis,CVD(P=0.000)and hepatitis/hepatocirrhosis(P= 0.001)were main death-related risk factors.The mortality seemed not to increase in SARS patients with DM.In recovered patients,60.4%of the patients with underling disease had a non-completely absorbed x-ray,and 29.9%of the patients without underling disease.SARS patients with underling disease had a significant high mortality.With more kinds of underling diseases the mortality enhance greatly.CVD and hepatitis/hepatocirrhosis are main death-related risk factors.SARS patients with underling disease have a severer damage on lung and their recovery are slower than the others.The mortality did not seem to increase in SARSpatients with DM.

Key words: severe acute respiratory syndrome, underlying disease, prognosis