Background Anosmia is common in Coronavirus disease 2019, but its impact on prognosis is unknown. We analysed whether anosmia predicts in-hospital mortality; and if patients with anosmia have a different clinical presentation, inflammatory response, or disease severity. Methods Retrospective cohort study including all consecutive hospitalized patients with confirmed Covid-19 from March 8th to April 11th, 2020. We determined all-cause mortality and need of intensive care unit (ICU) admission. We registered the first and worst laboratory parameters. Statistical analysis was done by multivariate logistic and linear regression. Results We included 576 patients, 43.3% female, and aged 67.2 years in mean. Anosmia was present in 146 (25.3%) patients. Patients with anosmia were more frequently females, younger and less disabled and had less frequently hypertension, diabetes, smoking habit, cardiac and neurological comorbidities. Anosmia was independently associated with lower mortality (OR: 0.180, 95% CI: 0.069–0.472) and ICU admission (OR: 0.438, 95% CI: 0.229–0.838, p = 0.013). In the multivariate analysis, patients with anosmia had a higher frequency of cough (OR: 1.96, 95%CI: 1.18–3.28), headache (OR: 2.58, 95% CI: 1.66–4.03), and myalgia (OR: 1.74, 95% CI: 1.12–2.71). They had higher adjusted values of hemoglobin (+0.87, 95% CI: 0.40–1.34), lymphocytes (+849.24, 95% CI: 157.45–1541.04), glomerular filtration rate (+6.42, 95% CI: 2.14–10.71), and lower D-dimer (−4886.52, 95% CI: −8655.29-(−1117.75)), and C-reactive protein (−24.92, 95% CI: −47.35-(−2.48)). Conclusions Hospitalized Covid-19 patients with anosmia had a lower adjusted mortality rate and less severe course of the disease. This could be related to a distinct clinical presentation and a different inflammatory response.

中文翻译：

---

嗅觉丧失与 COVID-19 住院死亡率降低相关

背景 嗅觉丧失在 2019 年冠状病毒病中很常见，但其对预后的影响尚不清楚。我们分析了嗅觉丧失是否可以预测院内死亡率；嗅觉丧失患者是否有不同的临床表现、炎症反应或疾病严重程度。方法 回顾性队列研究包括 2020 年 3 月 8 日至 4 月 11 日期间所有连续住院的确诊 Covid-19 患者。我们确定了全因死亡率和入住重症监护病房 (ICU) 的需要。我们记录了第一个和最差的实验室参数。通过多元逻辑回归和线性回归进行统计分析。结果 我们纳入了 576 名患者，其中 43.3% 为女性，平均年龄 67.2 岁。146 名 (25.3%) 患者存在嗅觉丧失。嗅觉丧失患者多为女性、年轻且残疾程度较低，且较少患有高血压、糖尿病、吸烟习惯、心脏和神经系统合并症。嗅觉丧失与较低的死亡率（OR：0.180，95％CI：0.069-0.472）和入住 ICU（OR：0.438，95％CI：0.229-0.838，p = 0.013）独立相关。在多变量分析中，嗅觉丧失患者咳嗽（OR：1.96，95％CI：1.18-3.28）、头痛（OR：2.58，95％CI：1.66-4.03）和肌痛（OR：1.74， 95% CI：1.12–2.71）。他们的血红蛋白（+0.87，95% CI：0.40–1.34）、淋巴细胞（+849.24，95% CI：157.45–1541.04）、肾小球滤过率（+6.42，95% CI：2.14–10.71）、和较低的 D-二聚体（-4886.52，95% CI：-8655.29-(-1117.75)）和 C 反应蛋白（-24.92，95% CI：-47.35-(-2.48)）。结论 患有嗅觉丧失的 Covid-19 住院患者调整后死亡率较低，病程较轻。这可能与不同的临床表现和不同的炎症反应有关。