【Cochrane简语概要】症状和医学检查能否准确诊断出COVID-19感染？

COVID-19是由SARS-CoV-2病毒引起的传染病。大多数感染COVID-19的人会患有轻度至中度呼吸道疾病；其他人则会患有重度疾病，例如COVID-19肺炎。常规诊断需要取鼻和咽部样本进行实验室分析，或进行如CT扫描等的影像学检查。然而，最先也是最容易获得的诊断信息是来自临床检查的症状和体征。如果通过症状和体征进行的初步诊断是准确的，则人们对耗时的专家诊断测试的需求就会减少。

患者普遍会出现症状 。轻度COVID-19患者可能会出现咳嗽、喉咙痛、高热、腹泻、头痛、肌肉或关节疼痛、疲劳以及嗅觉和味觉丧失等症状。COVID-19肺炎的症状包括呼吸困难、食欲不振、意识模糊、胸痛或胸闷以及高热（高于38°C）。

体征是通过临床检查评估的 ，包括肺音、血压和心率。

通常，症状较轻的人会去看医生（初级保健医生）以进行初步诊断。症状较严重的人可能会去医院的门诊或急诊就医。根据患者的症状和体征，他们可能会被送回家隔离，可能会接受进一步检查或住院。

为什么准确的诊断很重要？

准确的诊断可确保人们迅速得到正确的治疗；不用接受不必要的测试，处理或隔离；并且没有传播COVID-19的风险。这对个人很重要，可以节省时间和资源。

我们想知道什么？

我们想知道根据医学检查的症状和体征，在初级保健或医院环境中如何准确诊断出COVID-19和COVID-19肺炎。

我们做了什么？

我们检索了评估通过症状和体征诊断COVID-19和COVID-19肺炎准确性的研究。研究包括可能感染COVID-19的人，或已知已感染和未感染COVID-19的人。研究必须在初级保健或医院门诊进行，并且至少包括10名受试者，且具有COVID-19的症状或体征。

纳入的研究

我们检索到了16个相关的研究，共包含7706名受试者。研究评估了27种独立的体征和症状，但没有研究评估体征和症状的组合。七项研究在医院的门诊中进行（2172名受试者），四项研究在急诊科进行（1401名受试者），没有在初级保健机构中进行的研究。没有研究纳入儿童，只有一项研究针对老年人。所有的研究均通过最准确的检测以确定COVID-19的诊断。

主要结果

这些研究并未将轻度至中度的COVID-19感染与COVID-19肺炎明确区分，因此我们将两种情况的结果合并。

结果表明，至少有一半的COVID-19感染者有咳嗽，喉咙痛，高热，肌肉或关节疼痛，疲劳或头痛的症状。但是，咳嗽和喉咙痛在非COVID-19感染者中也很常见，因此仅靠这些症状对诊断COVID-19的作用较小。当出现高热，肌肉或关节疼痛，疲劳和头痛等症状时，感染COVID-19的可能性大大增加。

研究结果有多可靠？

个别症状和体征的诊断准确性在不同研究中差异很大。此外，这些研究对受试者的选择方式意味着基于症状和体征的检测的准确性可能不确定。

结论

所有研究都是在医院门诊环境中进行的，因此结果并不代表初级保健机构中的情况。结果不适用于儿童或老年人，也不能明确区分轻度COVID-19感染和COVID-19肺炎。

系统综述结果表明仅凭单一症状或体征不能准确诊断COVID-19。医生的诊断基于多种症状和体征，但研究并未反映出临床实践的这一方面。

需要进一步研究以调查症状和体征的组合；可能更具体的症状，例如嗅觉丧失；以及在基层医疗机构以及儿童和老年人中测试未选定的人群。需要进一步研究以调查通过症状和体征的组合诊断的准确性；症状可能更具体，比如失去嗅觉；并在初级保健机构、儿童和老年人等人群进行测试。

本综述的时效性如何？

本综述的作者检索了2020年1月至4月所发表的研究。

（图片来源于网络）

作者结论: 

本综述中包括的单个体征和症状的诊断性能很差，尽管这应该在选择偏倚和研究间的异质性的背景下进行解释。根据现有的资料，任何体征或症状的缺乏或出现都不足以准确地诊断或排除疾病。迫切需要对到初级保健或医院门诊就诊的，在现有研究未涉及的人群进行前瞻性研究，对其体征和症状进行结合的评估，评价COVID-19的症状表征。这些研究的结果可以为随后的管理决策提供信息，如自我隔离或选择患者进行进一步的诊断测试。我们还需要更具体症状（如嗅觉丧失）的相关资料。对老年人的研究尤其重要。

译者：刘旭，香港中文大学那打素护理学院；审校：李迅，北京中医药大学循证医学中心；编辑排版：张晓雯、郑偌祥，北京中医药大学循证医学中心

相关热门文章

【Cochrane Plain Language Summary】Can symptoms and medical examination accurately diagnose COVID-19 disease?

COVID-19 is an infectious disease caused by the SARS-CoV-2 virus. Most people with COVID-19 have a mild to moderate respiratory illness; others experience severe illness, such as COVID-19 pneumonia. Formal diagnosis requires laboratory analysis of nose and throat samples, or imaging tests like CT scans. However, the first and most accessible diagnostic information is from symptoms and signs from clinical examination. If initial diagnosis by symptoms and signs were accurate, the need for time-consuming, specialist diagnostic tests would be reduced.

Symptoms are experienced by patients. People with mild COVID-19 might experience cough, sore throat, high temperature, diarrhoea, headache, muscle or joint pain, fatigue, and loss of sense of smell and taste. Symptoms of COVID-19 pneumonia include breathlessness, loss of appetite, confusion, pain or pressure in the chest, and high temperature (above 38 °C).

Signs are evaluated by clinical examination, and include lung sounds, blood pressure and heart rate.

Often, people with mild symptoms visit their doctor (primary care physician) for an initial diagnosis. People with more severe symptoms might visit a hospital outpatient or emergency department. Depending on their symptoms and signs, patients may be sent home to isolate, may receive further tests or be hospitalised.

Why is accurate diagnosis important?

Accurate diagnosis ensures that people receive the correct treatment quickly; are not tested, treated or isolated unnecessarily; and do not risk spreading COVID-19. This is important for individuals and saves time and resources.

What did we want to find out?

We wanted to know how accurate diagnosis of COVID-19 and COVID-19 pneumonia is in a primary care or hospital setting, based on symptoms and signs from medical examination.

What did we do?

We searched for studies that assessed the accuracy of symptoms and signs to diagnose mild COVID-19 and COVID-19 pneumonia. Studies could include people with possible COVID-19, or people known to have – and not to have – COVID-19. Studies had to be in primary care or hospital outpatient settings only and include at least 10 participants with any symptom or sign that might be COVID-19.

The included studies

We found 16 relevant studies with 7706 participants. The studies assessed 27 separate signs and symptoms, but none assessed combinations of signs and symptoms. Seven were set in hospital outpatient clinics (2172 participants), four in emergency departments (1401 participants), but none in primary care settings. No studies included children, and only one focused on older adults. All the studies confirmed COVID-19 diagnosis by the most accurate tests available.

Main results

The studies did not clearly distinguish mild to moderate COVID-19 from COVID-19 pneumonia, so we present the results for both conditions together.

The results indicate that at least half of participants with COVID-19 disease had a cough, sore throat, high temperature, muscle or joint pain, fatigue, or headache. However, cough and sore throat were also common in people without COVID-19, so these symptoms alone are less helpful for diagnosing COVID-19. High temperature, muscle or joint pain, fatigue, and headache substantially increase the likelihood of COVID-19 disease when they are present.

How reliable are the results?

The accuracy of individual symptoms and signs varied widely across studies. Moreover, the studies selected participants in a way that meant the accuracy of tests based on symptoms and signs may be uncertain.

Conclusions

All studies were conducted in hospital outpatient settings, so the results are not representative of primary care settings. The results do not apply to children or older adults specifically, and do not clearly differentiate between milder COVID-19 disease and COVID-19 pneumonia.

The results suggest that a single symptom or sign included in this review cannot accurately diagnose COVID-19. Doctors base diagnosis on multiple symptoms and signs, but the studies did not reflect this aspect of clinical practice.

Further research is needed to investigate combinations of symptoms and signs; symptoms that are likely to be more specific, such as loss of sense of smell; and testing unselected populations, in primary care settings and in children and older adults.

How up to date is this review?

The review authors searched for studies published from January to April 2020.

Authors' conclusions: 

The individual signs and symptoms included in this review appear to have very poor diagnostic properties, although this should be interpreted in the context of selection bias and heterogeneity between studies. Based on currently available data, neither absence nor presence of signs or symptoms are accurate enough to rule in or rule out disease. Prospective studies in an unselected population presenting to primary care or hospital outpatient settings, examining combinations of signs and symptoms to evaluate the syndromic presentation of COVID-19 disease, are urgently needed. Results from such studies could inform subsequent management decisions such as self-isolation or selecting patients for further diagnostic testing. We also need data on potentially more specific symptoms such as loss of sense of smell. Studies in older adults are especially important.

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