Effectiveness of kumquat decoction for the improvement of cough caused by SARS-CoV-2 Omicron variants, a multicentre, prospective observational study

Qiaoli Hua; Lijuan Tang; Jingwei Shui; Yuntao Liu; Ge Zhang; Xiaohua Xu; Chunyuan Yang; Wenjian Gao; Guocheng Liao; Qingming Liu; Huilin Liang; Qingkun Mo; Fangxiu Liang; Jianwen Guo; Zhongde Zhang

doi:10.1016/j.phymed.2023.155008

Effectiveness of kumquat decoction for the improvement of cough caused by SARS-CoV-2 Omicron variants, a multicentre, prospective observational study

Phytomedicine. 2023 Nov:120:155008. doi: 10.1016/j.phymed.2023.155008. Epub 2023 Aug 11.

Authors

Qiaoli Hua¹, Lijuan Tang², Jingwei Shui³, Yuntao Liu⁴, Ge Zhang⁵, Xiaohua Xu⁴, Chunyuan Yang⁶, Wenjian Gao⁷, Guocheng Liao⁸, Qingming Liu⁹, Huilin Liang¹⁰, Qingkun Mo¹¹, Fangxiu Liang¹², Jianwen Guo¹³, Zhongde Zhang¹⁴

Affiliations

¹ The Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
² The Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China; Department of Emergency, the Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China.
³ Department of Emergency, the Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China.
⁴ Department of Emergency, the Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China; Guangdong Provincial Key Laboratory of Research on Emergency in TCM, Guangzhou 510120, China.
⁵ Development Research Center of Chinese Medicine, the Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China.
⁶ Yangshuo County Centre for Disease Control and Prevention, 541900, China.
⁷ Yangshuo County Hospital of Traditional Chinese Medicine, 541900, China.
⁸ Yangshuo County Baisha Township Hospital, 541900, China.
⁹ Yangshuo County Fuli Township Hospital, 541000, China.
¹⁰ Yangshuo County Gaotian Township Hospital, 541000, China.
¹¹ Yangshuo County Puyi Township Hospital, 541000, China.
¹² Yangshuo County Yangshuo Township Hospital, 541900, China.
¹³ Guangdong Provincial Key Laboratory of Research on Emergency in TCM, Guangzhou 510120, China; State Key Laboratory of Dampness Syndrome of Chinese Medicine, the Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510006, China; Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510006, China. Electronic address: drguo@gzucm.edu.cn.
¹⁴ Department of Emergency, the Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China; Guangdong Provincial Key Laboratory of Research on Emergency in TCM, Guangzhou 510120, China; State Key Laboratory of Dampness Syndrome of Chinese Medicine, the Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510006, China. Electronic address: doctorzzd99@gzucm.edu.cn.

PMID: 37651755
DOI: 10.1016/j.phymed.2023.155008

Abstract

Background: Kumquat decoction is a traditional Chinese medicine formula and has been widely used to alleviate the coronavirus disease 2019 (COVID-19)-related cough in China. However, the effectiveness and safety of kumquat decoction remain unclear.

Purpose: To assess the effectiveness and safety of kumquat decoction for COVID-19-related cough.

Study design: A multicentre, prospective observational study.

Methods: We enrolled consecutive patients with mild-to-moderate COVID-19 from December 31, 2022, to January 3, 2023, during the Omicron phase in Yangshuo County, China. The primary outcome was the time from study baseline to sustained cough resolution by the last follow-up day on January 31, 2023. The effectiveness was evaluated by Cox proportional hazards models based on propensity score analyses. The secondary outcomes were the resolution of cough and other COVID-19-related symptoms by Days 3, 5, and 7.

Results: Of 1434 patients, 671 patients were excluded from the analysis of cough resolution. Among the remaining 763 patients, 481 (63.04%) received kumquat decoction, and 282 (36.96%) received usual care. The median age was 38.0 (interquartile range [IQR] 29.0, 50.0) years, and 55.7% were women. During a median follow-up of 7.000 days, 68.2% of patients in the kumquat group achieved sustained cough resolution (93.77 per 1000 person-days) compared to 39.7% in the usual care group (72.94 per 1000 person-days). The differences in restricted mean survival time (RMST) (kumquat decoction minus usual care group) for cough resolution were -0.742 days (95% CI, -1.235 to -0.250, P = 0.003) on Day 7. In the main analysis using propensity-score matching, the adjusted hazard ratio (HR) for cough resolution (kumquat decoction vs. usual care group) was 1.94 (95% CI, 1.48 to 2.53, P < 0.001). Similar findings were found in multiple sensitivity analyses. In addition, the use of kumquat decoction was associated with the resolution of cough, and a stuffy nose on Days 5 and 7, as well as the resolution of sore throat on Day 7 following medication.

Conclusion: In this study among patients with COVID-19-related cough, receiving kumquat decoction was associated with an earlier resolution of cough symptoms.

Keywords: COVID-19; Cough; Kumquat decoction; Traditional Chinese medicine.

Publication types

Observational Study
Multicenter Study

MeSH terms

COVID-19* / complications
Cough / drug therapy
Female
Humans
Male
Rutaceae*
SARS-CoV-2

Supplementary concepts

SARS-CoV-2 variants