Abstract：
OBJECTIVE: To investigate effectiveness of olfactory training (OT) in COVID-19 patients with persistent olfactory dysfunction (OD).
METHODS: From March 2020 to March 2022, COVID-19 patients with OD were prospectively followed in three European medical centers for a period of 18 months. A standardized OT protocol were recommended to patients. Patient-reported outcome questionnaires and psychophysical evaluations were used to evaluate olfaction at baseline, 6, 12, and 18 months after the start of OT. The evolution of olfactory outcome was compared according to the adherence to the OT protocol.
RESULTS: Fifty-seven patients completed the evaluations. Thirty-two patients fully adhered to the OT, while 25 did not adhere. The psychophysical scores significantly improved from baseline to 6-month post-infection in both groups. In the OT group, the psychophysical scores continued to significantly improve from 6 to 12 months after the start of OT (p = 0.032). The mean duration of OT was 15.4 weeks. The mean delay of patient recovery perception was comparable between groups (27.4 weeks). The occurrence of cacosmia (35.1%) and parosmia (43.9%) throughout the follow-up period was comparable between groups. There proportion of phantosmia was higher in training (34.4%) compared with no-OT (16.0%; p = 0.007) group. The baseline Sniffin\'Sticks tests was positively associated with the 6-month Sniffin\'Sticks tests (rs = 0.685; p < 0.001) and negatively associated with the time of recovery (rs = - 0.369; p = 0.034).
CONCLUSIONS: The adherence to an OT protocol was associated with better mid-term improvement of psychophysical scores. Future large-cohort randomized-controlled studies are needed to confirm the effectiveness of OT in COVID-19 patients.
METHODS: From March 2020 to March 2022, COVID-19 patients with OD were prospectively followed in three European medical centers for a period of 18 months. A standardized OT protocol were recommended to patients. Patient-reported outcome questionnaires and psychophysical evaluations were used to evaluate olfaction at baseline, 6, 12, and 18 months after the start of OT. The evolution of olfactory outcome was compared according to the adherence to the OT protocol.
RESULTS: Fifty-seven patients completed the evaluations. Thirty-two patients fully adhered to the OT, while 25 did not adhere. The psychophysical scores significantly improved from baseline to 6-month post-infection in both groups. In the OT group, the psychophysical scores continued to significantly improve from 6 to 12 months after the start of OT (p = 0.032). The mean duration of OT was 15.4 weeks. The mean delay of patient recovery perception was comparable between groups (27.4 weeks). The occurrence of cacosmia (35.1%) and parosmia (43.9%) throughout the follow-up period was comparable between groups. There proportion of phantosmia was higher in training (34.4%) compared with no-OT (16.0%; p = 0.007) group. The baseline Sniffin\'Sticks tests was positively associated with the 6-month Sniffin\'Sticks tests (rs = 0.685; p < 0.001) and negatively associated with the time of recovery (rs = - 0.369; p = 0.034).
CONCLUSIONS: The adherence to an OT protocol was associated with better mid-term improvement of psychophysical scores. Future large-cohort randomized-controlled studies are needed to confirm the effectiveness of OT in COVID-19 patients.
摘要：
目的：探讨嗅觉训练（OT）对COVID-19持续性嗅觉功能障碍（OD）患者的疗效。
方法：从2020年3月至2022年3月，在三个欧洲医疗中心对患有OD的COVID-19患者进行了为期18个月的前瞻性随访。向患者推荐标准化的OT方案。患者报告的结果问卷和心理物理学评估用于评估基线时的嗅觉。OT开始后6、12和18个月。根据OT方案的依从性比较嗅觉结果的演变。
结果：57名患者完成了评估。32名患者完全坚持OT，25没有坚持。从基线到感染后6个月，两组的心理物理评分均显着改善。在OT组中，OT开始后6~12个月,心理物理评分持续显著改善(p=0.032).OT的平均持续时间为15.4周。患者恢复感知的平均延迟在组间具有可比性（27.4周）。在整个随访期间，两组之间的Cacmomia（35.1％）和parosmia（43.9％）的发生率具有可比性。与无OT组（16.0％；p=0.007）相比，训练中的幻影比例更高（34.4％）。基线Sniffin\'Sticks测试与6个月Sniffin\'Sticks测试呈正相关（rs=0.685；p<0.001），与恢复时间呈负相关（rs=-0.369；p=0.034）。
结论：坚持OT方案与更好的中期心理物理评分改善相关。未来的大队列随机对照研究需要证实OT在COVID-19患者中的有效性。
方法：从2020年3月至2022年3月，在三个欧洲医疗中心对患有OD的COVID-19患者进行了为期18个月的前瞻性随访。向患者推荐标准化的OT方案。患者报告的结果问卷和心理物理学评估用于评估基线时的嗅觉。OT开始后6、12和18个月。根据OT方案的依从性比较嗅觉结果的演变。
结果：57名患者完成了评估。32名患者完全坚持OT，25没有坚持。从基线到感染后6个月，两组的心理物理评分均显着改善。在OT组中，OT开始后6~12个月,心理物理评分持续显著改善(p=0.032).OT的平均持续时间为15.4周。患者恢复感知的平均延迟在组间具有可比性（27.4周）。在整个随访期间，两组之间的Cacmomia（35.1％）和parosmia（43.9％）的发生率具有可比性。与无OT组（16.0％；p=0.007）相比，训练中的幻影比例更高（34.4％）。基线Sniffin\'Sticks测试与6个月Sniffin\'Sticks测试呈正相关（rs=0.685；p<0.001），与恢复时间呈负相关（rs=-0.369；p=0.034）。
结论：坚持OT方案与更好的中期心理物理评分改善相关。未来的大队列随机对照研究需要证实OT在COVID-19患者中的有效性。
