目的：分析年龄≥60岁新型冠状病毒（新冠）奥密克戎变异株感染者核酸转阴时间的影响因素。方法：收集2022年4月—6月上海部分定点医院600例年龄≥60岁、感染新冠奥密克戎变异株患者的临床信息和核酸转阴时间，根据核酸转阴时间分为≤14 d组和>14 d组，比较2组患者临床特征，分析年龄、确诊至使用Paxlovid时间与核酸转阴时间的相关性，采用Logistic回归分析性别、年龄、疫苗接种、基础疾病、确诊至使用Paxlovid时间对患者14 d内核酸转阴的影响。结果：患者平均核酸转阴时间为15（12~18） d，年龄、确诊至使用Paxlovid时间与患者核酸转阴时间有明显线性趋势（P=0.006，P<0.001）。单因素Logistic回归分析显示，年龄、存在恶性肿瘤、确诊至使用Paxlovid时间与14 d内核酸转阴明显相关（P=0.028，P=0.038，P=0.042），多因素Logistic回归分析显示，年龄和确诊至使用Paxlovid时间≤3 d与14 d内核酸转阴独立相关（P=0.007，OR=0.802；P=0.003，OR=2.402）。结论：对于年龄≥60岁新冠奥密克戎变异株感染者，年龄越大核酸转阴时间越长，存在恶性肿瘤可能导致核酸转阴时间延长。Paxlovid尽早使用（≤3 d）可缩短核酸转阴时间。

Objective To analyze the influence factors on nucleic acid negative conversion time in severe acute respiratory syndromes coronavirus 2(SARS-CoV-2) Omicron infected patients over 60 years old. Methods The patients over 60 years old infected SARS-CoV-2 Omicron in one designated hospital of Shanghai during April and June of 2022 were enrolled and the information including clinical data and nucleic acid negative conversion time were collected. The patients were divided into ≤14-day group and >14-day group based on nucleic acid negative conversion time, and clinical characteristics of two groups were compared. The correlation between age, time from diagnosis to Paxlovid use and nucleic acid negative conversion time was analyzed. Logistic regression analysis was used to analyze the influence of sex, age, vaccination, basic diseases and time from diagnosis to Paxlovid use on nucleic acid negative conversion time. Results The average day of nucleic acid negative conversion time was 15(12-18) d. As age and time from diagnosis to Paxlovid use increased, nucleic acid negative conversion time increased gradually (P=0.006, P<0.001). The univariate Logistic regression analysis showed that age, malignancy and time from diagnosis to Paxlovid use were related to nucleic acid negative conversion time ≤14 d (P=0.028, P=0.038, P=0.042). The multivariate Logistic regression analysis showed that age and time from diagnosis to Paxlovid use ≤3 d were independently related to nucleic acid negative conversion time ≤14 d (P=0.007, OR=0.802; P=0.003, OR=2.402). Conclusions In SARS-CoV-2 Omicron infected patients over 60 years old, increased age is related to longer nucleic acid negative conversion time, and the patients having malignant tumor also have delayed negative conversion time, while early using Paxlovid (≤3 d) could shorten nucleic acid negative conversion time.