病毒性肝炎继发感染与皮质激素治疗的因果联系——病因研究中的混杂与交互作用

An Analysis of the Secondary Infection of Viral Hepatitis with Corticoid Therapy--The Confounding Factor and Interaction in Studies of Pathogenesis

本研究以我校两个附属医院传染科住院的病毒性肝炎病例762名为调查对象,以使用皮质激素与否,用回顾性队列研究的设计方案进行调查分析。初步结果提示皮质激素治疗是肝炎病人医院感染的危险因素。又按病情轻重将全部病例分作重症与中等严重两组进行分层分析,证明病情轻重具有混杂作用,并提示本研究的两个危险因素之间又有交互作用。通过分层分析明确了促使肝炎继发感染的主要危险因素为肝炎的病情轻重问题,但皮质激素治疗对继发感染也有一定的增强作用。因此,在治疗中必须十分重视保护与提高患者自身的免疫防御机能。对皮质激素的使用应根据实际情况慎重考虑。

A total of 762 cases of viral hepatitis admitted tothe two teaching hospital of Third Military MedicalCollege were used for study. They were divided intotwo groups depending upon whether corticoid treat-ment were given, As the result of cRR=6.06,X^2=174.17, P<0.01, it is obvious that the corticoidtherapy is a risk factor for the secondary infection inpatients suffered from viral hepatitis. For getting rid of the interference of confoundingfactor and interaction a stratified analysis was per-formed. These patients were again divided into severetype and moderate type according to the severity ofthe disease. The results of stratified analysis wereaRR(F)=3.05 and aRR(F)=1.48, cRR>aRR. Thesefindings demonstrated that the degree of severity ofpatients played a primary role in the secondary infec-tion of hepatitis and showed that the confounding fac-tor was present. On the other hand, the result ofaRR(F)≠aRR(F) indicated that the interaction alsoexists simultaneously. This research suggests that special attentionshould be paid to manintain and increase the level ofimmunological defence function in pateints ofhepatitis. And it is necessory to restrict the indiscrimi-nate usage of corticoids particularly in severe patientsfor preventing nosocomial infection.