The COX regression analysis on the use of corticosteroids in the treatment of SARS

Abstract

To explore the effectiveness of corticosteroids (GCS) and to determine how to use it in the treatment of SARS. All reported probable cases in Beijing were reviewed. Those who fulfilled the diagnostic criteria with an integrity clinical record were recruited in the study. A database was established and all the clinical data, including patients' personal information, epidemiological history, underlying diseases, clinical manifestations, laboratory tests and therapies after hospitalization, as well as the outcome of the disease, were inputted under a quality control. Unifactor and COX multifactor regression analysis were done. The dose of GCS was all expressed in that of methylprednisolone. 1291 cases were in consistence with the demands mentioned above. Among them, 1084 cases (83.96%) had used GCS and 207 did not in the course of SARS. There was no significant difference of average age (t = -1.08, P = 0.2808) and the time from SARS onset to hospitalization (P = 0.2797) between the two groups. COX regression showed that the risk of fatality in the GCS group was higher than that of those who did not use GCS (RR = 1.334, 95% of CI: 0.588 - 3.026). In the patients with comorbidities, RR was 2.086 (95% of CI: 0.694 - 6.267), and RR was 0.536 (95% of CI: 0.146 - 1.970) in the patients with no comorbidity. In those without any comorbidity, the initial doses, maximal doses, average doses and cumulative doses all showed a 'J' shape change. An appropriate dose could keep RR to be the lowest whereas the doses either higher or lower than it could increase RR. The initial dose with the lowest RR was 80 - 160 mg/d, the maximum 80 - 160 mg/d, the average < 80 mg/d and the cumulative one 1000 - 3000 mg although there was no statistical significance (all P > 0.05). RR was less than 1 in non-comorbidity patients who initiated GCS therapy before the 15th day of the disease. RR was 1.415 (95% of CI: 0.195 - 10.257) in the patients who began to use GCS over this period. Counting from hospitalization, the time of GCS use also showed a 'J' type change of RR. The initiation of GCS from day 5 to 7 had the lowest RR (0.282, 95% of CI: 0.043 - 1.828) and that from day 8 to 14 was 1 (95% of CI: 0.150 - 6.654). In the treatment of SARS, GCS seems to be effective. An appropriate dose and a right time of application decrease the risk of death. The use of GCS in SARS patients with comorbidities should be with caution.