Background. Although mean platelet volume (MPV) appears to be associated with poor outcome of pneumonia, the relationship between MPV and in-hospital mortality is unclear in severe pneumonia (SP) patients. Methods. In this retrospective cohort study, 115 SP patients from June 1st, 2016, to September 29th, 2019, were included and divided into two groups. The primary outcome was in-hospital mortality. The receiver operating characteristic (ROC) curve was performed to assess the predictive ability for in-hospital mortality. Kaplan-Meier cumulative incidence curves were applied to observe the incidence of mortality. Multivariable Cox regression analyses were used to evaluate the hazard ratios (HRs). Besides, a formal test for interaction was investigated to analyze the relationship between MPV and sex. Results. During the course of hospitalization, 63 cases of mortality were recorded. ROC analysis suggested that MPV had a modest power for predicting in-hospital mortality (, 95% CI: 0.628-0.818, ). Yet the cutoff value of MPV was 10.5 (%; %). Compared to the low-MPV group, the high-MPV group had significantly increased in-hospital mortality (log-rank , ), while the adjusted Cox model indicated that the high-MPV group was associated with an elevated risk of in-hospital mortality (HR: 2.267, 95% CI: 1.166-4.406, ). Moreover, analyses of in-hospital mortality suggested a significant interaction between optimal MPV level and sex (). In a multivariate Cox model which included females only, a high MPV level was associated with increased risk of in-hospital mortality (HR: 11.387, 95% CI: 1.767-73.380, ). Conclusion. High MPV level is an independent risk factor for in-hospital mortality in patients with SP.

中文翻译：

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高平均血小板体积与重症肺炎患者的住院死亡率相关。

背景。尽管平均血小板体积 (MPV) 似乎与肺炎的不良预后相关，但在重症肺炎 (SP) 患者中，MPV 与住院死亡率之间的关系尚不清楚。方法. 在这项回顾性队列研究中，将 2016 年 6 月 1 日至 2019 年 9 月 29 日的 115 名 SP 患者纳入研究，并分为两组。主要结局是住院死亡率。采用受试者工作特征 (ROC) 曲线评估对住院死亡率的预测能力。应用Kaplan-Meier累积发病率曲线观察死亡率。多变量 Cox 回归分析用于评估风险比 (HR)。此外，还研究了一个正式的交互测试来分析 MPV 和性别之间的关系。结果。在住院期间，记录了63例死亡病例。ROC 分析表明 MPV 在预测住院死亡率方面具有适度的功效（, 95% CI: 0.628-0.818,）。然而 MPV 的临界值是 10.5 (%;%）。与低 MPV 组相比，高 MPV 组的住院死亡率显着增加（log-rank, )，而调整后的 Cox 模型表明，高 MPV 组与住院死亡率风险升高相关（HR：2.267，95% CI：1.166-4.406，）。此外，对住院死亡率的分析表明，最佳 MPV 水平与性别之间存在显着的相互作用。）。在仅包括女性的多变量 Cox 模型中，高 MPV 水平与住院死亡率风险增加相关（HR：11.387，95% CI：1.767-73.380，）。 结论。高 MPV 水平是 SP 患者住院死亡率的独立危险因素。