倾向指数配比分析（PSM）：MRSA与MSSA医院获得性肺炎预后比较

目的研究耐甲氧西林金黄色葡萄球菌（MRSA）是否增加医院获得性肺炎（HAP）患者的负担。方法选择2013年1月1日—2014年11月31日某院金黄色葡萄球菌肺炎感染者，病例组为MRSA HAP患者，对照组为甲氧西林敏感金黄色葡萄球菌（MSSA）HAP患者，采用倾向指数配比分析（PSM）,比较MRSA与MSSA HAP预后（住院时间、感染至出院时长、病死率、总治疗成本）。结果PSM匹配前病例组APACHE II评分高于对照组，住院时间［40(20,94)d］、感染至出院时长［19(10,46)d］均长于对照组［分别为28(21,53)、17(8,29)d］（均P＜0.05）。匹配后病例组和对照组APACHE II评分比较，差异无统计学意义（P＞0.05），资料均衡可比；两组患者住院时间［28(21,52)d vs 28(21,53) d］、感染至出院时长［15(9,25)d vs17(8,29) d］、病死率［10.87% vs 15.22%］、治疗总费用［121 013.5(80 747.21, 176 200) 元 vs 119 911.2(66 994.08,241 184.7)元］比较，差异均无统计学意义（均P＞0.05）。结论APACHE II评分是影响预后的重要因素；均衡此因素后，MRSA和MSSA HAP患者预后无差异，MRSA HAP未增加疾病负担。

Comparison in prognosis of hospital acquired pneumonia due to methicillin resistant and methicillin sensitive Staphylococcus aureus: analysis of propensity score matching

ObjectiveTo study whether methicillin resistant Staphylococcus aureus (MRSA) will increase the burden of patients with hospital acquired pneumonia (HAP). MethodsPatients with Staphylococcus aureus HAP in a hospital between January 1, 2013 and November 31, 2014 were selected, patients with MRSA HAP were as case group, patients with methicillin sensitive Staphylococcus aureus( MSSA) HAP were as control group, propensity score matching (PSM) analysis were conducted to compare the prognosis of MRSA HAP and MSSA HAP (length of hospital stay, duration from infection to discharge, mortality, total therapeutic cost). ResultsAPACHE II score in case group was higher than control group before PSM was conducted, length of hospital stay and duration from infection to discharge were both longer than control group (40［20,94］d vs 28［21,53］ d; 19［10,46］ d vs 17［8,29］d, respectively, both P<0.05). APACHE II score in case group and control group after conducting PSM was not significantly different（P＞0.05），data were balanced and comparable; there were no significant difference in length of hospital stay between two groups (28［21,52］d vs 28［21,53］d), duration from infection to discharge (15［9,25］d vs17［8,29］ d), mortality(10.87% vs 15.22%), and total therapeutic cost (121 013.5［80 747.21, 176 200］ yuan vs 119 911.2［66 994.08,241 184.7］yuan)（all P＞0.05）.ConclusionAPACHE II score is an important factor affecting prognosis; after balancing this factor, there is no difference in the prognosis of patients with MRSA and MSSA HAP, MRSA HAP can not increase the burden of disease.