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Randomized Controlled Clinical Trials of Warm Herbal Foot Bath Therapy for Insomnia: A Literature Review Based on the CNKI

불면증에 대한 한방 족욕요법의 무작위 대조군 임상연구 현황 : CNKI를 중심으로

Article information

J Int Korean Med. 2023;44(4):726-740
Publication date (electronic) : 2023 September 30
doi : https://doi.org/10.22246/jikm.2023.44.4.726
권찬영1, 이보람2, 이경은3
1 동의대학교 한의과대학 한방신경정신과학교실
1 Dept. of Oriental Neuropsychiatry, Dong-eui University College of Korean Medicine
2 한국한의학연구원 한의과학연구부
2 KM Science Research Division, Korea Institute of Oriental Medicine
3 동의대학교부속한방병원
3 Dong-eui University Korean Medicine Hospital
·Corresponding author: Chan-Young Kwon Dept. of Oriental Neuropsychiatry, Dong-eui University College of Korean Medicine, 52-57, Yangjeong-ro, Busanjin-gu, Busan, Republic of Korea TEL: +82-51-850-8808 FAX: +82-51-867-5162 E-mail: beanalogue@deu.ac.kr
Received 2023 September 6; Revised 2023 September 21; Accepted 2023 September 22.

Trans Abstract

Objectives:

This review investigated the research on warm herbal foot bath therapy (WHFT) for insomnia.

Methods:

A search was conducted on the China National Knowledge Infrastructure (CNKI) database to collect relevant studies published up to August 29, 2023. Randomized controlled trials (RCTs) comparing WHFT and sleeping pills in patients with insomnia were included. The methodological quality of the included studies was assessed using the Cochrane risk-of-bias assessment tool. The results of the meta-analysis were presented as risk ratios (RRs) or mean differences (MDs) and their 95% confidence intervals (CIs).

Results:

A total of 11 RCTs were included. WHFT as monotherapy resulted in a significantly higher total effective rate (TER) (RR, 1.25; 95% CI, 1.15 to 1.36; I2=25%) and an improved Pittsburgh Sleep Quality Index (PSQI) global sore (MD, -3.10; 95% CI, -4.24 to -1.95; I2=73%) compared to benzodiazepines. Additionally, WHFT as a combined therapy with benzodiazepines resulted in a significantly higher TER (RR, 1.15; 95% CI, 1.04 to 1.27; I2=0%) and an improved PSQI global score (MD, -2.23; 95% CI, -4.09 to -0.38; I2=80%) compared to benzodiazepines alone. In network analysis visualizing the components of HWFT, four clusters were discovered, and Polygoni Multiflori Ramuls and Ziziphi Spinosae Semen were the key herbs used in WHFT. Overall, the methodological quality of the included studies was poor.

Conclusions:

There was limited evidence that WHFT as a monotherapy or combined therapy was effective in improving insomnia. The findings can be used as basic data for future WHFT research in South Korea.

Abstract

초 록

목적:

이 연구의 목적은 불면증에 대한 한방 족욕요법의 연구 동향을 검토하는 것이다.

방법:

관련 연구의 수집을 위해 CNKI에서 검색을 수행하여, 2023년 8월 29일까지 발표된 연구를 검토하였다. 불면증 환자를 대상으로 한방 족욕요법과 수면제를 비교한 무작위 대조군 임상시험 만을 분석에 포함하였다. 포함된 연구들의 방법론적 질은 Cochrane risk-of-bias assessment tool을 사용하여 평가하였다. 메타분석의 결과는 위험비(risk ratios, RRs)와 평균차(mean differences, MDs) 및 그 95% 신뢰구간(confidence intervals, CIs)으로 제시되었다.

결과:

총 11편의 무작위 대조군 임상시험이 포함되었다. 분석 결과, 한방 족욕요법은 벤조디아제핀계 약물과 비교하여 유의하게 더 높은 총유효율(RR, 1.25; 95% CI, 1.15 to 1.36; I2=25%)과 개선된 피츠버그 수면의 질 지수(Pittsburgh Sleep Quality Index, PSQI) 총 점수(MD, -3.10; 95% CI, -4.24 to -1.95; I2=73%)를 보였다. 또한, 벤조디아제핀계 약물에 한방 족욕요법을 병용한 경우, 벤조디아제핀계 약물을 단독으로 사용한 것과 비교하여 유의하게 더 높은 총유효율(RR, 1.15; 95% CI, 1.04 to 1.27; I2=0%)과 개선된 PSQI 총 점수(MD, -2.23; 95% CI, -4.09 to -0.38; I2=80%)을 보였다. 네트워크 분석을 통해 한방 족욕요법에 포함된 약재를 분석하고 시각화한 결과, 4개의 클러스터가 발견되었으며, 핵심 약재는 야교등과 산조인이었다. 포함된 연구들의 방법론적 질은 전반적으로 낮았다.

결론:

이 연구는 불면증 개선에 있어서 단독요법 또는 병행치료로서의 한방 족욕요법이 효과적이라는 제한된 수준의 근거를 보여준다. 이 연구의 발견은 향후 한국에서 시행할 한방 족욕요법 연구의 기초자료로 활용될 수 있을 것이다.

I. Introduction

Approximately 10% of the adult population worldwide suffers from insomnia disorder, and this condition poses a significant public health burden1. The prevalence of insomnia in the elderly is especially high. According to a study conducted in Korea, 32.8% of the elderly over 60 years old suffer from insomnia disorder2. Insomnia disorder is a type of hyperarousal disorder experienced throughout the day and can be explained by both cognitive and physiological models of insomnia3. Among them, the cognitive model of insomnia serves as the theoretical basis for cognitive behavioral therapy for insomnia (CBT-I), an important non-pharmacological treatment for chronic insomnia4. Although this treatment is one of the most well-established treatments for chronic insomnia, due to limitations in accessibility, lack of knowledge, and lack of treatment motivation, CBT-I has been underutilized in clinical settings5. On the other hand, pharmacological treatment for chronic insomnia includes benzodiazepines and benzodiazepine receptor agonists, but their adverse side effects and lethal overdose have been pointed out6.

Therefore, it is important to discover non- pharmacological treatments that are effective for insomnia and highly available, and in this context, complementary and integrative medicine has received attention. According to the results of a network meta-analysis analyzing the comparative effectiveness of available non-pharmacological treatments for insomnia in the elderly, acupuncture alone or in combination with benzodiazepines was found to be effective in improving sleep quality7. In addition, a recently published multicenter, assessor-blinded, randomized controlled, pilot clinical trial found the effectiveness of electroacupuncture for cancer-related insomnia8. Given that it is difficult to challenge dysfunctional beliefs about sleep with acupuncture alone, as found in clinical trials comparing CBT-I and acupuncture9, the therapeutic mechanism of acupuncture is presumed to be primarily related to physiological models of insomnia3, including autonomic regulation10.

Another non-pharmacological treatment potentially involved in the physiological pathology of insomnia is foot baths. The effect of foot baths on improving sleep quality has been proven through some clinical trials11,12, and some of the mechanisms are thought to induce a relaxation response. In traditional East Asian medicine (TEAM), medicinal herbs have been used together with warm foot baths, namely herbal warm foot bath therapy (HWFT), to treat insomnia. HWFT is a kind of herbal external application, and an evidence-based clinical practice guideline published in China in 2012 recommended that herbal external application can be helpful for insomnia patients13. Some herbs may contribute to the treatment of insomnia through a synergistic effect when combined with a warm foot baths, but the additional clinical benefits of HWFT on the treatment of insomnia have not been reviewed. In South Korea, where TEAM, including herbal medicine, is frequently used, there has been no randomized controlled clinical studies (RCTs) investigating the effectiveness or efficacy of HWFT for insomnia. Therefore, this study aimed to investigate the current status of RCTs comparing HWFT and sleeping pills for insomnia, through a search in Chinese database.

II. Methods and materials

1. Search strategy

In this study, a search was conducted on China National Knowledge Infrastructure, a representative platform for Chinese research. The search was conducted on 29 August 2023, and all studies published up to the date of the search were reviewed. The search strategy was as follows: [subject] ‘herbal medicine’ AND [subject] ‘foot bath’ AND [subject] ‘insomnia’. The search was performed by one researcher (CYK).

2. Inclusion and exclusion criteria

The inclusion and exclusion criteria used in this study can be presented in the following PICOS format. 1) Population: Insomnia patient. There were no restrictions on the diagnostic criteria for insomnia and concomitant conditions. Also, there were no restrictions on sex/gender, age, or ethnicity of participants. 2) Intervention: HWFT. In this study, HWFT refers to warm foot bath therapy combined with herbs based on the principles of TEAM. As an intervention in the treatment group, HWFT was allowed to be used alone or in combination with sleeping pills. 3) Control: Benzodiazepines and benzodiazepine receptor agonists, which are standard drug treatments for chronic insomnia6, were allowed as controls. 4) Outcome: Studies reporting sleep-related outcomes were included. The primary outcome was the Pittsburgh Sleep Quality Index (PSQI)14, and other outcomes were considered to be secondary. 5) Study design: Only RCTs were accepted. Other study designs were excluded. Gray literature was allowed. There were no restrictions on publication language.

3. Study selection

Study selection was conducted by two independent researchers (CYK, BL) based on the inclusion criteria described above. Study selection was conducted in two steps. In the first step, titles and abstracts of documents were reviewed for potential relevance. In the second step, the full-text of the screened documents were carefully reviewed. Any disagreements between the researchers were resolved through discussion between them.

4. Data extraction

The following information was extracted from included studies using a predefined standardized Excel form: information for risk of bias assessment, country in which the study was conducted, publication language, sample size, mean age and sex ratio of participants, and pattern identification, materials and procedures of HWFT, outcome, results, and adverse events. Data extraction was conducted by two independent researchers (CYK, BL). Any disagreements between the researchers were resolved through discussion between them.

5. Assessment of methodological quality

The Cochrane risk-of-bias assessment tool15 was used to assess the methodological quality of included studies. Using the standard methodology of this assessment tool15, included studies were assessed. Using this tool, the risk of bias was assessed as low, high, or unclear for each of the following seven domains: random sequence generation, allocation concealment; blinding of participants and personnel; blinding of outcome assessment; incomplete outcome data; selective reporting; and other sources of bias15. In case of other sources of bias, if the clinical equivalence of the treatment group and the control group at baseline was statistically reported, it was rated as low. Assessment of methodological quality was conducted by two independent researchers (CYK, BL). Any disagreements between the researchers were resolved through discussion between them.

6. Data analysis

All included studies were analyzed qualitatively. In addition, meta-analysis was conducted when two or more studies reported the same outcome. However, considering the potential heterogeneity of the HWFT used, the random-effect model was used in the meta-analysis. Meta-analyses for dichotomous variables were expressed as risk ratios (RRs) and their 95% confidence intervals (CIs), and meta-analyses for continuous variables were expressed as mean differences (MDs) and their 95% CIs. The I-square value was used to evaluate statistical heterogeneity, and if this value was greater than 50%, statistical heterogeneity was interpreted as significant16. Meta-analysis was conducted using Review Manager version 5.4 software (Cochrane, London, UK).

In this study, an analysis of the HWFT used was conducted. Specifically, the material, timing, duration, amount of liquid used, temperature (°C), treatment frequency, and treatment period were analyzed. In particular, herbs used in HWFT were analyzed by frequency, and their composition was clustered and visualized as a network using VOSviewer version 1.6.18 (Centre for Science and Technology Studies, Leiden University, Leiden, The Netherlands). In this network, the size of the nodes indicates the frequency of use of each herb, and the lines between nodes indicate the connectivity of the prescription composition between the herbs.

III. Results

1. Search results

Among the 233 initially searched documents, 204 irrelevant documents were excluded through the first step of screening. After reviewing the full-text of the remaining 29 documents, exclusion occurred for the following reasons: Combination treatment (but not sleeping pills) was used with HWFT (n=9), HWFT was used equally for both groups (n=1), not RCT (n=6); and sleeping pills were not used in the control group (n=2). Finally, 11 RCTs17-27 were included in this review (Fig. 1).

Fig. 1

PRISMA flow diagram of this study.

HWFT : herbal warm foot bath therapy, RCT : randomized controlled clinical trial

2. Characteristics of included studies

Included studies17-27 were published between 2009 and 2021. These studies were all conducted in China and published in Chinese. The sample sizes of these studies varied from 32 to 126, and the mean was 81.73. Except for one study24 that did not provide the average age of participants, the average age of participants in all remaining studies was over 40 years old. Nine studies17-19,21,23-27 recruited patients with primary insomnia, and the remaining two studies included comorbid conditions, including post-stroke insomnia20 and perimenopausal insomnia22. Eight studies17-19,21-24,27 compared HWFT with benzodiazepines, and other three studies20,25,26 compared HWFT combined with benzodiazepines and benzodiazepines alone. The treatment period varied from 7 to 90 days, with an average of 27.64 days. The most frequently reported outcome measure was total effective rate (TER) (n=10), followed by PSQI (n=7). The basic characteristics of the included studies are summarized in Table 1.

Characteristics of Included Studies

3. Methodological quality of included studies

Among the included studies, four studies21,24,26,27 were evaluated as low in the random sequence generation domain using randomization methods such as random number tables. One study19 was evaluated as high in this domain because it assigned treatment and control groups according to the order of hospitalization. In the remaining studies17,18,20,22,23,25, the methods were not described and were evaluated as unclear in this domain. Only one study26 described the allocation concealment method. Because the included studies were studies comparing HWFT and sleeping pills, double blinding was deemed impossible. There were no studies reporting blinding of outcome assessment. In the included studies, there were no or small number of participants dropping out, and the reasons were stated, so the studies were evaluated as low in the incomplete outcome data domain. In selective reporting, studies17-19 that reported only TER were evaluated as high because this outcome is not a validated evaluation tool for sleep disorders. Statistical equivalence between the two groups at baseline was reported in all studies, so all other sources of bias domains were rated as low (Fig. 2).

Fig. 2

Results of risk of bias graph and summary.

‘+’ indicates low risk of bias, ‘-’ indicates high risk of bias, and ‘?’ indicates unclear risk of bias.

4. Methods of HWFT used in included studies

A total of 15 HWFT prescriptions were presented in the 11 included studies17-27. As a result of the analysis, 44 types of herbs were used a total of 113 times, and an average of 7.53 herbs were included per HWFT. As a result of frequency analysis of the medicinal herbs used, Polygoni Multiflori Ramuls (n=10) was most commonly used, followed by Zizyphi Spinosae Semen (n=8), Salviae Miltiorrhizae Radix (n=6), and Albizziae Cortex (n=6) (Table 2). Four major clusters could be established in the nodes consisting of each herb (resolution, 0.65; minimum cluster size, 1). The largest cluster was centered around Polygoni Multiflori Ramuls and Zizyphi Spinosae Semen. The second cluster was centered on Albizziae Cortex, Angelicae Gigantis Radix, and Bupleuri Radix. The third cluster was centered on Salviae Miltiorrhizae Radix. Lastly, the fourth cluster was centered on Ophiopogonis Radix (Fig. 3). In the nine studies18-25,27 that described the timing of HWFT, all included the timing at night or before bedtime. Most studies17,18,21-27 performed HWFT once a day, but one study20 performed HWFT four times a day and the other19 conducted HWFT twice a day. The optimal duration of HWFT per session was commonly 30 minutes. The optimal amount of liquid used for each HWFT was commonly 2.0-3.0 liters. When performing HWFT, the optimal temperature of the liquid was commonly 40-43 °C (Table 2).

Details of HWFT for Insomnia

Fig. 3

Network map of herbs for HWFT.

Red, green, blue, and yellow represent each cluster.

5. Effectiveness and safety of HWFT on insomnia

All included studies were included in the meta- analysis. Meta-analysis was performed on TER, PSQI global score, and incidence of adverse events. According to the results, HWFT as monotherapy showed significantly higher TER (RR, 1.25; 95% CI, 1.15 to 1.36; I2=25%) and improved PSQI global sore (MD, -3.10; 95% CI, -4.24 to -1.95; I2=73%) compared to benzodiazepines (Fig. 4(a), (b)). Also, HWFT as combined therapy with benzodiazepines showed significantly higher TER (RR, 1.15; 95% CI, 1.04 to 1.27; I2=0%) and improved PSQI global sore (MD, -2.23; 95% CI, -4.09 to -0.38; I2=80%) compared to benzodiazepines alone (Fig. 5(a), (b)). A meta-analysis on the incidence of adverse events was possible in the comparison between HWFT and benzodiazepines. The results indicated that there was no significant difference on incidence of adverse events between HWFT and benzodiazepines groups (RR, 0.09; 95% CI, 0.01 to 1.07; I2=0%) (Fig. 4(c)). Deng26 compared incidence of adverse event between daily HWFT combined with estazolam 2 mg/d and estazolam 2 mg/d alone for 28 days. As a result, the HWFT group had statistically significantly lower incidence of adverse events (2/61 vs. 8/59, p<0.05).

Fig. 4

Meta-analysis on HWFT as monotherapy: (a) total effective rate, (b) global score of the Pittsburgh sleep quality index, (c) incidence of adverse events.

HWFT : herbal warm foot bath therapy

Fig. 5

Meta-analysis on HWFT as combined therapy: (a) total effective rate, (b) global score of the Pittsburgh sleep quality index.

HWFT : herbal warm foot bath therapy

IV. Discussion

This study was conducted to investigate trends in RCTs that investigated the therapeutic effect of HWFT in improving insomnia compared to sleeping pills. According to the results of analyzing the 11 included RCTs, HWFT showed a significantly higher TER and more improved PSQI compared to estazolam or diazepam as monotherapy or combination therapy for an average treatment period of about 1 month. The key herbs of HWFT for improving insomnia were Polygoni Multiflori Ramuls and Zizyphi Spinosae Semen. However, in addition to this, a cluster centered on Albizziae Cortex, a cluster centered on Salviae Miltiorrhizae Radix, and a cluster centered on Ophiopogonis Radix were identified. HWFT was recommended to be performed once a day for 30 minutes before bedtime, and is described to be performed at 40-43 °C with 2.0-3.0 liters of liquid. However, the methodological quality of the included studies was overall poor. In particular, due to the nature of HWFT and sleeping pills, blinding of participants and personnel was not possible. Moreover, assessor blinding was unclearly described in all studies.

Sleep is mediated by changes in core body temperature. When heat is dissipated from the peripheral part of the body, core body temperature decreases, which promotes drowsiness28. Warm foot bath increases peripheral blood flow without increasing core body temperature and transfers core heat to the peripheral region. It is thought that this will promote the loss of body temperature in the peripheral region, induce sleep onset, and improve sleep quality12. Foot bathing itself affects the activity of the autonomic nervous system, and especially promotes relaxation responses by increasing the activity of the parasympathetic nervous system29. In addition, warm foot bath can be combined with some herbs to improve skin permeability and increase the absorption rate of ingredients effective for insomnia30. It is possible that the aromatic volatiles of some herbs added to warm water may be absorbed by the patient’s nasal mucosa31. One study included in this review found increases in serum dopamine and serotonin associated with HWFT27. These research results suggest that HWFT has the potential to improve sleep not only through thermal stimulation but also through the biological effects of medicinal ingredients. However, there is a lack of research investigating the underlying mechanisms explaining the sleep improvement effect of HWFT. It is expected that future research in this field will be able to mimic research on foot baths using essential oils. For example, a study examining the effects of a foot bath using Lindera umbellate essential oil on individuals found that this foot bath increased parasympathetic nervous system activity and improved negative mood32.

Although there is a lack of evidence to clearly support the benefits of HWFT in the treatment of insomnia, this treatment has the advantage of being highly available and considered a safe non- pharmacological treatment. Compared to half-body baths, foot baths are considered safer and more beneficial as they gradually increase peripheral circulation33. In clinical practice, foot baths can be combined with foot reflexology and used synergistically to improve sleep34. In other words, given the importance of introducing non-pharmacological therapies in the treatment of insomnia, especially chronic insomnia6, HWFT is likely to be an attractive non-pharmacological option. More importantly, this treatment can also be used in patients who cannot or have difficulty using sleeping pills. However, there is still a lack of research investigating the sleep improvement effect of HWFT in South Korea, so related clinical research can be conducted considering the findings in this study.

The following limitations of this review are acknowledged. First, this study did not conduct a sufficiently comprehensive search, but mainly focused on collected studies of HWFT in traditional Chinese medicine, so there may be potentially relevant but missing studies. However, given that most research in this field is being conducted in China, we can roughly estimate the effect of HWFT on insomnia through the results of this study. Second, the methodological quality of the included studies is overall poor. This means that the reliability of the results obtained from these studies is challenged. Additionally, it is acknowledged that our findings may be significantly affected by the results of future rigorously conducted studies. Third, placebo effects may have played a role in the findings. The included studies were unable to be double-blinded due to the nature of the interventions, and some Chinese participants may have favored HWFT, a type of traditional Chinese medicine. Future studies could perform comparisons between HWFT and warm foot baths without herbs to better understand the effectiveness of HWFT on insomnia.

V. Conclusion

This study was conducted to investigate trends in RCTs that investigated the therapeutic effect of HWFT in improving insomnia compared to sleeping pills. HWFT showed a significantly higher TER and more improved PSQI compared to estazolam or diazepam as monotherapy or combination therapy for an average treatment period of about 1 month. There was limited evidence that HWFT as monotherapy or combined therapy was effective in improving insomnia. In this review, the composition and procedures of HWFT were analyzed in detail, which can be used as basic data for future HWFT research in South Korea.

Acknowledgement

This research was supported by the MSIT (Ministry of Science and ICT), Korea, under the Grand Information Technology Research Center support program (IITP-2023-2020-0-01791) supervised by the IITP (Institute for Information & communications Technology Planning & evaluation).

References

1. Morin CM, Jarrin DC. Epidemiology of Insomnia:Prevalence, Course, Risk Factors, and Public Health Burden. Sleep Med Clin 2022;17(2):173–91.
2. Kim KW, Kang SH, Yoon IY, Lee SD, Ju G, Han JW, et al. Prevalence and clinical characteristics of insomnia and its subtypes in the Korean elderly. Arch Gerontol Geriatr 2017;68:68–75.
3. Roth T. Insomnia:definition, prevalence, etiology, and consequences. J Clin Sleep Med 2007;3(5 Suppl):S7–10.
4. Sharma MP, Andrade C. Behavioral interventions for insomnia:Theory and practice. Indian J Psychiatry 2012;54(4):359–66.
5. Koffel E, Bramoweth AD, Ulmer CS. Increasing access to and utilization of cognitive behavioral therapy for insomnia (CBT-I):a narrative review. J Gen Intern Med 2018;33(6):955–62.
6. Sateia MJ, Buysse DJ, Krystal AD, Neubauer DN, Heald JL. Clinical Practice Guideline for the Pharmacologic Treatment of Chronic Insomnia in Adults:An American Academy of Sleep Medicine Clinical Practice Guideline. J Clin Sleep Med 2017;13(2):307–49.
7. Kwon CY, Lee B, Cheong MJ, Kim TH, Jang BH, Chung SY, et al. Non-pharmacological Treatment for Elderly Individuals With Insomnia:A Systematic Review and Network Meta-Analysis. Front Psychiatry 2020;11:608896.
8. Lee B, Kim BK, Kim M, Kim AR, Park HJ, Kwon OJ, et al. Electroacupuncture for treating cancer-related insomnia:a multicenter, assessor- blinded, randomized controlled, pilot clinical trial. BMC Complement Med Ther 2022;22(1):77.
9. Xing J, Wu X, Liu H, Wang J, Jiang S, Lozada A, et al. Effects of Electroacupuncture Therapy and Cognitive Behavioral Therapy in Chronic Insomnia:A Randomized Controlled Study. Evid Based Complement Alternat Med 2020;2020:5630130.
10. Li QQ, Shi GX, Xu Q, Wang J, Liu CZ, Wang LP. Acupuncture effect and central autonomic regulation. Evid Based Complement Alternat Med 2013;2013:267959.
11. Seyyedrasooli A, Valizadeh L, Zamanzadeh V, Nasiri K, Kalantri H. The effect of footbath on sleep quality of the elderly:a blinded randomized clinical trial. J Caring Sci 2013;2(4):305–11.
12. Sung EJ, Tochihara Y. Effects of bathing and hot footbath on sleep in winter. J Physiol Anthropol Appl Human Sci 2000;19(1):21–7.
13. Chinese Society of Neurology DoSD. Diagnosis and Treatment of Insomnia in Adult in China. Chin J Neurol 2012;45(7):534–40.
14. Buysse DJ, Reynolds CF 3rd, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh Sleep Quality Index:a new instrument for psychiatric practice and research. Psychiatry Res 1989;28(2):193–213.
15. Higgins JP, Altman DG, Gøtzsche PC, Jüni P, Moher D, Oxman AD, et al. The Cochrane Collaboration's tool for assessing risk of bias in randomised trials. Bmj 2011;343:d5928.
16. West SL, Gartlehner G, Mansfield AJ, et al. Comparative Effectiveness Review Methods:Clinical Heterogeneity [Internet] Rockville (MD): Agency for Healthcare Research and Quality (US);2010 Sep. Table 7, Summary of common statistical approaches to test for heterogeneity; Available from: https://www. ncbi.nlm.nih.gov/books/NBK53317/table/ch3.t2/.
17. Huang W. Effectiveness of footbath with Chinese medicine for patients with insomnia. Chinese Clinical Nursing 2009;1(01):38–9.
18. Ma Z. Discussion on the treatment of insomnia based on syndrome differentiation and differentiation of traditional Chinese medicine. Modern Journal of Integrated Traditional Chinese and Western Medicine 2012;21(30):3357–8.
19. Tang L. Observation on the effect of traditional Chinese medicine foot bath in treating insomnia patients. Journal of HeBei United University Health Sciences 2014;16(01):74.
20. Chen H, Lin H, Chen R, Huang Y, Xu Y, Zhong Z. Effect of traditional Chinese medicine foot bath on sleep quality in patients with post-stroke insomnia. Journal of Qilu Nursing 2016;22(13):67–9.
21. Lu L. Observation on Therapeutic Effect of Traditional Chinese Medicine Foot Bath in Treating Insomnia with Deficiency of Heart and Spleen. Journal of Practical Traditional Chinese Medicine 2017;33(01):79–80.
22. Liang X. Clinical research effect by traditional Chinese medicine foot bath in the treatment of perimenopausal insomnia. Chinese Journal of Modern Drug Application 2017;11(05):175–7.
23. Deng Y, Zhou N, Zhou J, Liu H, Chen L. A Randomized Controlled Study on Treating Insomnia with Yang Deficiency Constitution by Fumigation and Washing with Traditional Chinese Medicine Foot Bath. Zhejiang Journal of Traditional Chinese Medicine 2017;52(01):21–2.
24. Cao D, Li W, Li X. Effect of traditional Chinese medicine foot bath therapy on the clinical efficacy of insomnia patients. Chinese General Practice Nursing 2018;16(23):2903–4.
25. He T. Clinical Observation on 30 Cases of Heart-Kidney Disharmony Type Perimenopausal Insomnia Treated by Traditional Chinese Medicine Foot Bath. Hunan Journal of Traditional Chinese Medicine 2018;34(11):63–4.
26. Deng Y, Zhou J, Chen L. Clinical Study of Chinese Medicine Foot Bath Combined with Western Medicine for Insomnia with Qi Depression Constitution. New Journal of Traditional Chinese Medicine 2018;50(11):71–4.
27. Wang X, Huang H, Yang Y. Efficacy of foot bath with TCM medicine on elderly patients with insomnia. Clinical Journal of Chinese Medicine 2021;13(07):95–7.
28. Czeisler CA, Weitzman E, Moore-Ede MC, Zimmerman JC, Knauer RS. Human sleep:its duration and organization depend on its circadian phase. Science 1980;210(4475):1264–7.
29. Saeki Y. The effect of foot-bath with or without the essential oil of lavender on the autonomic nervous system:a randomized trial. Complement Ther Med 2000;8(1):2–7.
30. Fan G, Huang H, Lin Y, Zheng G, Tang X, Fu Y, et al. Herbal medicine foot bath for the treatment of diabetic peripheral neuropathy:protocol for a randomized, double-blind and controlled trial. Trials 2018;19(1):483.
31. Shi MM, Piao JH, Xu XL, Zhu L, Yang L, Lin FL, et al. Chinese medicines with sedative- hypnotic effects and their active components. Sleep Med Rev 2016;29:108–18.
32. Kitajima M, Miura M, Nanashima N, Tomisawa T, Takamagi S, Fujioka M, et al. Psychological and Antibacterial Effects of Footbath Using the Lindera umbellata Essential Oil. Molecules 2021;26(17):5128.
33. Takahashi Y, Okura K, Kaga M, Yoshioka M. Effects of half-body and foot baths on peripheral circulation in healthy adult males:a pilot study. J Phys Ther Sci 2022;34(10):652–6.
34. Rahmani A, Naseri M, Salaree MM, Nehrir B. Comparing the Effect of Foot Reflexology Massage, Foot Bath and Their Combination on Quality of Sleep in Patients with Acute Coronary Syndrome. J Caring Sci 2016;5(4):299–306.

Article information Continued

Fig. 1

PRISMA flow diagram of this study.

HWFT : herbal warm foot bath therapy, RCT : randomized controlled clinical trial

Table 1

Characteristics of Included Studies

Study Sample size (included →analyzed) Mean age (range) (yr) Population (diagnostic criteria) Mean disease period Intervention Treatment duration (day) Outcome Adverse events
Huang 2009 60 (30:30) →60 (30:30) TG : 74.7 (68-79)
CG : 75.6 (69-80)
Insomnia (CCMD-3) / NA TG : 29.4 d
CG : 27.8 d
HWFT vs. Estazolam 1 mg/d 7 1. TER : no statistical analysis NR

Ma 2012 120 (60:60) →120 (60:60) TG : 62.5 (25-78)
CG : 60.7 (23-83)
Insomnia (CCMD-3) / Different prescriptions were used according to five patterns TG : 1 m-12 y
CG : 2 m-10 y
HWFT vs. Diazepam 2.5 mg/d 30 1. TER : TG>CG* TG : 0/60
CG : 56/60

Tang 2014 90 (45:45) →90 (45:45) TG : 50.3 (18-70)
CG : 51.2 (16-75)
Insomnia (ICD-10) / NA TG : 2.9 y
CG : 3.1 y
HWFT vs. Estazolam 1 mg/d 14 1. TER : TG>CG* NR

Chen 2016 64 (32:32) →64 (32:32) TG : 72.2±18.1 (56-92)
CG : 70.4±17.6 (56-90)
Post-stroke insomnia (PSQI≥7) / NA TG : 29.2±7.2 d
CG : 30.2±5.9 d
HWFT +Estazolam 2 mg/d vs. Estazolam 2 mg/d 7 1. PSQI : TG<CG+ 2. TER : TG>CG* NR

Lu 2017 87 (44:43) →87 (44:43) TG : 50.3±5.6 (NR)
CG : 51.1±5.8 (NR)
Insomnia (CCMD-3) / dual deficiency of the heart-spleen TG : 5.8±2.6 y
CG : 5.9±2.7 y
HWFT vs. Estazolam 2 mg/d 14 1. PSQI : TG<CG* 2. TER : TG>CG* NR

Liang 2017 80 (40:40) →80 (40:40) TG : 51.76±2.82 (41-60)
CG : 52.09±3.07 (40-61)
Perimenopausal insomnia (NR) / NA NR HWFT vs. Diazepam 2.5 mg/d 30 1. Spiegel Sleep Questionnaire : TG>CG* (in all sub-items) 2. TER : TG>CG* NR

Deng 2017 110 (55:55) →105 (53:52) TG : 43.91±10.53 (NR)
CG : 44.13±11.15 (NR)
Insomnia (CCMD-3) / yang deficiency constitution TG : 16.08±13.50 m
CG : 15.33±10.84 m
HWFT vs. Estazolam 2 mg/d 28 1. PSQI : TG<CG* 2. TER : TG>CG* TG : 2/53
CG : 6/52

Cao 2018 70 (35:35) →70 (35:35) NR Insomnia (CCMD-3) / NA NR HWFT vs. Estazolam 28 1. PSQI : TG<CG+ NR

He 2018 60 (30:30) →60 (30:30) TG : 50.3±3.8 (NR)
CG : 50.5±3.2 (NR)
Insomnia (CCMD-3) / non-interaction between the heart and kidney TG : 5.8±2.6 y
CG : 5.9±2.7 y
HWFT +Estazolam 2 mg/d vs. Estazolam 2 mg/d 90 1. PSQI : TG<CG* 2. TER: TG>CG* NR

Deng 2018 126 (63:63) →120 (61:59) TG : 43.19±11.12 (NR)
CG : 42.24±10.95 (NR)
Insomnia (CCMD-3) / qi depression constitution TG : 16.29±12.49 m
CG : 15.56±11.64 m
HWFT +Estazolam 2 mg/d vs. Estazolam 2 mg/d 28 1. PSQI : TG<CG* 2. TER : TG>CG* TG : 2/61
CG : 8/59

Wang 2021 32 (16:16) →32 (16:16) TG : 71.58±4.16 (62-80)
CG : 71.61±4.12 (63-79)
Insomnia (Guidelines for Diagnosis and Treatment of Insomnia in China) / NA TG :
4.58±1.47 y
CG :
4.55±1.45 y
HWFT vs. Estazolam 1 mg/d 28 days 1. PSQI : TG<CG* 2. TER : TG>CG* 3. serum DA : TG>CG+
4. serum 5-HT : TG>CG+
TG : 1/16
CG : 6/16
*

: p<0.05, + : p<0.01

Fig. 2

Results of risk of bias graph and summary.

‘+’ indicates low risk of bias, ‘-’ indicates high risk of bias, and ‘?’ indicates unclear risk of bias.

Table 2

Details of HWFT for Insomnia

Study Composition Timing Duration Amount of liquid Temperature (℃) Treatment frequency
Huang 2009 Salviae Miltiorrhizae Radix, Zizyphi Spinosae Semen, Biotae Semen, Evodiae Fructus 40 g each, Leonuri Herba, Bupleuri Radix, Ligustici Rhizoma 30 g each, Rehmanniae Radix, Polygalae Radix 20 g each NR 20-30 min 1.5-2.0 L 40-45 once a day

Ma 2012 1) depressed liver qi transforming into fire : Albizziae Cortex, Bupleuri Radix, Chrysanthemi Flos, Celosiae Semen 20 g each
2) internal harassment of phlegm-heat : Scutellariae Radix, Bambusae Caulis In Taeniam, Aurantii Nobilis Pericarpium, Poria (Hoelen) 20 g each
3) yin deficiency with effulgent fire : Phellodendri Cortex, Hoelen cum Pini Radix, Ophiopogonis Radix, Adenophorae Radix 20 g eachxyb4) dual deficiency of the heart-spleen : Codonopsis Pilosulae Radix, Zizyphi Spinosae Semen, Poria (Hoelen), Schizandrae Fructus 20 g each
5) heart deficiency with timidity : Biotae Semen, Polygoni Multiflori Ramuls, Ostreae Concha 20 g each, Rhinocerotis Ossis Fossilia 30 g
Night 25-30 min NR NR once a day

Tang 2014 Rehmanniae Radix, Leonuri Herba, Schizandrae Fructus, Bupleuri Radix 15 g each, Zizyphi Spinosae Semen, Polygoni Multiflori Ramuls 20 g each, Salviae Miltiorrhizae Radix 30 g, Ligustici Rhizoma 10 g, Cinnabaris 1 g, Glycyrrhizae Radix 6 g Morning, night 30 min 2.5-3.0 L 35-50 twice a day

Chen 2016 Salviae Miltiorrhizae Radix 30 g, Zizyphi Spinosae Semen, Rhinocerotis Ossis Fossilia 20 g each, Polygoni Multiflori Ramuls, Albizziae Cortex, Hoelen cum Pini Radix 15 g each 1 hour after each meal, 30 minutes before bedtime 20 min 3.0 L 38-43 four times a day

Lu 2017 Codonopsis Pilosulae Radix, Atractylodis Rhizoma Alba, Angelicae Gigantis Radix, Astragali Radix, Zizyphi Spinosae Semen, Polygalae Radix, Polygoni Multiflori Ramuls 30 g each, Poria (Hoelen) 20 g, Glycyrrhizae Radix 10 g 30 minutes before bedtime 30 min 4.0 L 40 once a day

Liang 2017 Rehmanniae Radix Preparat, Angelicae Gigantis Radix, Polygoni Multiflori Ramuls 50 g each, Coptidis Rhizoma 25 g, Albizziae Cortex 15 g 30 minutes before bedtime 30 min 1.0 L 37-42 once a day

Deng 2017 Cinnamomi Ramulus, Angelicae Gigantis Radix, Ligustici Rhizoma, Coptidis Rhizoma, Aurantii Nobilis Pericarpium 10 g each, Morindae Radix, Bupleuri Radix, Paeoniae Radix Alba, Olibanum, Cyperi Rhizoma, Ophiopogonis Radix 15 g each, Succinum 3 g, Polygoni Multiflori Ramuls 30 g, Albizziae Cortex 20 g 30 minutes before bedtime 30 min 2.0-3.0 L 40-43 once a day

Cao 2018 Magnetitum, Rhinocerotis Ossis Fossilia, Astragali Radix 30 g each, Zizyphi Spinosae Semen 20 g, Chrysanthemi Flos, Polygoni Multiflori Ramuls, Scutellariae Radix, Albiziae Flos 15 g each, Glycyrrhizae Radix 2 g 30 minutes before bedtime 15-20 min NR NR once a day

He 2018 Angelicae Gigantis Radix, Salviae Miltiorrhizae Radix, Rehmanniae Radix Preparat, Coptidis Rhizoma, Biotae Semen 10 g each, Polygoni Multiflori Ramuls 15 g, Ophiopogonis Radix 20 g, Zizyphi Spinosae Semen 30 g 30 minutes before bedtime 30 min 0.5 L 40 once a day

Deng 2018 Bupleuri Radix, Paeoniae Radix Alba, Gardeniae Fructus, Curcumae Radix 15 g each, Ligustici Rhizoma, Rehmanniae Radix, Acori Graminei Rhizoma, Salviae Miltiorrhizae Radix, Angelicae Gigantis Radix, Coptidis Rhizoma 10 g each, Polygoni Multiflori Ramuls 30 g, Albizziae Cortex 20 g, Succinum 3 g NR 30 min 2.0-3.0 L 40-43 once a day

Wang 2021 Acori Graminei Rhizoma, Curcumae Radix, Ligustici Rhizoma, Cyperi Rhizoma 10 g each, Leonuri Herba, Albizziae Cortex, Polygoni Multiflori Ramuls, Carthami Flos 15 g each, Zizyphi Spinosae Semen 20 g, Salviae Miltiorrhizae Radix 30 g Night 30 min 1.5-2.0 L 42 once a day

NR : not reported

Fig. 3

Network map of herbs for HWFT.

Red, green, blue, and yellow represent each cluster.

Fig. 4

Meta-analysis on HWFT as monotherapy: (a) total effective rate, (b) global score of the Pittsburgh sleep quality index, (c) incidence of adverse events.

HWFT : herbal warm foot bath therapy

Fig. 5

Meta-analysis on HWFT as combined therapy: (a) total effective rate, (b) global score of the Pittsburgh sleep quality index.

HWFT : herbal warm foot bath therapy