Institute of Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany.
Department of Clinical Neuroscience, Division of Psychology, Karolinska Institutet, Stockholm, Sweden.
JMIR Public Health Surveill. 2024 May 10;10:e47064. doi: 10.2196/47064.
Smell disorders are commonly reported with COVID-19 infection. The smell-related issues associated with COVID-19 may be prolonged, even after the respiratory symptoms are resolved. These smell dysfunctions can range from anosmia (complete loss of smell) or hyposmia (reduced sense of smell) to parosmia (smells perceived differently) or phantosmia (smells perceived without an odor source being present). Similar to the difficulty that people experience when talking about their smell experiences, patients find it difficult to express or label the symptoms they experience, thereby complicating diagnosis. The complexity of these symptoms can be an additional burden for patients and health care providers and thus needs further investigation.
This study aims to explore the smell disorder concerns of patients and to provide an overview for each specific smell disorder by using the longitudinal survey conducted in 2020 by the Global Consortium for Chemosensory Research, an international research group that has been created ad hoc for studying chemosensory dysfunctions. We aimed to extend the existing knowledge on smell disorders related to COVID-19 by analyzing a large data set of self-reported descriptive comments by using methods from natural language processing.
We included self-reported data on the description of changes in smell provided by 1560 participants at 2 timepoints (second survey completed between 23 and 291 days). Text data from participants who still had smell disorders at the second timepoint (long-haulers) were compared with the text data of those who did not (non-long-haulers). Specifically, 3 aims were pursued in this study. The first aim was to classify smell disorders based on the participants' self-reports. The second aim was to classify the sentiment of each self-report by using a machine learning approach, and the third aim was to find particular food and nonfood keywords that were more salient among long-haulers than those among non-long-haulers.
We found that parosmia (odds ratio [OR] 1.78, 95% CI 1.35-2.37; P<.001) as well as hyposmia (OR 1.74, 95% CI 1.34-2.26; P<.001) were more frequently reported in long-haulers than in non-long-haulers. Furthermore, a significant relationship was found between long-hauler status and sentiment of self-report (P<.001). Finally, we found specific keywords that were more typical for long-haulers than those for non-long-haulers, for example, fire, gas, wine, and vinegar.
Our work shows consistent findings with those of previous studies, which indicate that self-reports, which can easily be extracted online, may offer valuable information to health care and understanding of smell disorders. At the same time, our study on self-reports provides new insights for future studies investigating smell disorders.
新冠病毒感染常伴有嗅觉障碍。与新冠相关的嗅觉问题可能会持续存在，即使呼吸道症状已经消退。这些嗅觉功能障碍的范围从嗅觉缺失（完全失去嗅觉）或嗅觉减退（嗅觉下降）到嗅觉异常（感知到的气味不同）或幻嗅（感知到不存在的气味）。类似于人们在谈论嗅觉体验时所经历的困难，患者发现很难表达或标记他们所经历的症状，从而使诊断变得复杂。这些症状的复杂性可能会给患者和医疗保健提供者带来额外的负担，因此需要进一步研究。
本研究旨在探讨患者的嗅觉障碍问题，并通过使用全球化学感觉研究联合会（一个专门为研究化学感觉障碍而成立的国际研究小组）在 2020 年进行的纵向调查，为每种特定的嗅觉障碍提供概述。我们旨在通过使用自然语言处理方法分析自我报告的描述性评论的大型数据集，扩展与新冠相关的嗅觉障碍的现有知识。
我们纳入了 1560 名参与者在两个时间点（第二次调查在第 23 天至 291 天之间完成）提供的关于嗅觉变化描述的自我报告数据。将第二次仍有嗅觉障碍的参与者（长途跋涉者）的文本数据与没有嗅觉障碍的参与者（非长途跋涉者）的文本数据进行比较。具体而言，本研究有三个目标。第一个目标是根据参与者的自我报告对嗅觉障碍进行分类。第二个目标是使用机器学习方法对每个自我报告的情绪进行分类，第三个目标是找到在长途跋涉者中比非长途跋涉者更突出的特定食物和非食物关键词。
我们发现，与非长途跋涉者相比，长途跋涉者中更常报告嗅觉异常（优势比 [OR] 1.78，95%置信区间 [CI] 1.35-2.37；P<.001）和嗅觉减退（OR 1.74，95% CI 1.34-2.26；P<.001）。此外，我们还发现长途跋涉者的状态与自我报告的情绪之间存在显著关系（P<.001）。最后，我们发现了一些特定的关键词，这些关键词在长途跋涉者中比在非长途跋涉者中更为典型，例如火、气、酒和醋。
我们的工作与之前的研究结果一致，表明可以从网上轻松提取的自我报告可能为医疗保健和嗅觉障碍的理解提供有价值的信息。同时，我们对自我报告的研究为未来调查嗅觉障碍的研究提供了新的见解。
