Liu D T, Pellegrino R, Sabha M, Altundag A, Damm M, Poletti S C, Croy I, Hähner A, Oleszkiewicz A, Cuevas M, Hummel T
Smell and Taste Clinic, Department of Otorhinolaryngology, Medical Faculty Carl-Gustav Carus, Technical University of Dresden, Dresden, Germany.
Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria.
Rhinology. 2020 Sep 9. doi: 10.4193/Rhin20.262.
Olfactory training (OT) represents a therapeutic option for multiple etiologies of olfactory dysfunction (OD) that also benefits normosmic subjects. In this retrospective study, we report the effectiveness of OT and factors associated with relevant changes in olfactory function (OF) in large groups of normosmic participants and patients with OD, including a control group that performed no training.
This was a retrospective pooled analysis including 2 treatment cohorts of 8 previously published studies. Adult partici- pants that either presented with the major complaint of quantitative OD or normosmic volunteers were recruited at various ENT clinics and received OT or no training. The outcome was based on changes in objective olfactory test scores after OT.
A total of 601 patients with OD or normosmic subjects were included. OT was more effective compared to no training. No interaction was found between OT and OF. In multivariate analysis, higher baseline OF (adjusted odds ratio, aOR, 0.93) and posttraumatic (aOR, 0.29) or idiopathic OD (aOR, 0.18) compared to postinfectious causes were significantly associated with lower odds of relevant improvements in patients with OD receiving OT. Subgroup analysis of normosmic participants receiving OT further revealed a significant association of age and baseline olfactory function with improvements of overall OF.
This study demonstrated that OT was more effective than no training in patients with various causes of OD. Additi- onally, baseline olfactory performance and etiology of OD were identified as important factors associated with relevant improve- ments after OT.
嗅觉训练（OT）是多种病因所致嗅觉功能障碍（OD）的一种治疗选择，对嗅觉正常的受试者也有益处。在这项回顾性研究中，我们报告了OT在大量嗅觉正常参与者和OD患者中的有效性，以及与嗅觉功能（OF）相关变化的影响因素，其中包括一个未进行训练的对照组。
这是一项回顾性汇总分析，纳入了8项先前发表研究中的2个治疗队列。在多家耳鼻喉科诊所招募了以定量OD为主诉的成年参与者或嗅觉正常的志愿者，他们接受了OT或未接受训练。结果基于OT后客观嗅觉测试分数的变化。
共纳入601例OD患者或嗅觉正常的受试者。与未训练相比，OT更有效。未发现OT与OF之间存在相互作用。在多变量分析中，与感染后病因相比，基线OF较高（调整优势比，aOR，0.93）以及创伤后（aOR，0.29）或特发性OD（aOR，0.18）的OD患者接受OT后相关改善的几率显著降低。对接受OT的嗅觉正常参与者进行亚组分析进一步显示，年龄和基线嗅觉功能与总体OF的改善显著相关。
本研究表明，对于各种病因的OD患者，OT比不训练更有效。此外，基线嗅觉表现和OD的病因被确定为与OT后相关改善相关的重要因素。
