RESEARCH ARTICLE

Acupuncture in persons with an increased

stress level—Results from a randomized-

controlled pilot trial

Beate WildID 1*, Judith Brenner1, Stefanie Joos2, Yvonne Samstag3, Magdalena Buckert1,

Jan ValentiniID 2

1 Department of General Internal Medicine and Psychosomatics, Medical University Hospital Heidelberg,

Heidelberg, Germany, 2 Institute for General Practice and Interprofessional Care, Medical University Hospital

Tübingen, Tübingen, Germany, 3 Institute of Immunology, Section Molecular Immunology, Heidelberg

University, Heidelberg, Germany

* beate.wild@med.uni-heidelberg.de

Abstract

Background

In today’s Western societies a high percentage of people experience increased or chronic

stress. Acupuncture could serve as treatment for persons affected adversely by the

increased stress.

Methods

The AkuRest study was a two-centre randomized controlled pilot study in adult persons with

increased stress levels. Participants were randomly allocated to one of three groups: verum

acupuncture treatment, sham acupuncture, and a waiting control group. The feasibility of

the study was assessed. In addition, effects on stress level (measured by the Perceived

Stress Questionnaire (PSQ-20)) and other variables were assessed at the end of treatment

and a 3-month follow-up.

Results

Altogether, N = 70 persons were included in the study. At the end of the treatment 15.7%

were lost to follow-up. The adherence to the protocol was good: 82.9% of the participants

completed 100% of their treatment. The stress level of the participants was high at baseline

(mean PSQ-20 score 75.5, SD = 8.2). Effect sizes (ES) at T1 showed that verum and sham

acupuncture were superior to the waiting condition in reducing stress (ES (verum) = -1.39,

95%-CI = [-2.11; -0.67]: ES (sham) = -1.12, CI = [-1.78;-0.44]). At follow-up, effect sizes

were in favour of the verum group (as compared to sham). However, confidence intervals

and t-tests showed that these differences were not significant.

PLOS ONE

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OPEN ACCESS

Citation: Wild B, Brenner J, Joos S, Samstag Y,

Buckert M, Valentini J (2020) Acupuncture in

persons with an increased stress level—Results

from a randomized-controlled pilot trial. PLoS ONE

15(7): e0236004. https://doi.org/10.1371/journal.

pone.0236004

Editor: Stephen L Atkin, Weill Cornell Medical

College Qatar, QATAR

Received: December 4, 2019

Accepted: June 25, 2020

Published: July 23, 2020

Copyright: © 2020 Wild et al. This is an open access article distributed under the terms of the

Creative Commons Attribution License, which

permits unrestricted use, distribution, and

reproduction in any medium, provided the original

author and source are credited.

Data Availability Statement: The data generated

or analysed during this study is included in this

published article (and its Supplementary

Information files).

Funding: Funding statement: Parts of the study

were supported by AZKIM (academic centre for

complementary and integrative medicine, www.

azkim.de) which was funded by the Ministry of

Science, Research and the Arts Baden-

Württemberg, Germany. Other parts of the study

were internally funded by the Department of

Conclusion

The pilot study demonstrated the feasibility of the acupuncture RCT in persons with

increased stress levels. Estimated parameters can be used to design a larger RCT to prove

the–here indicated—efficacy of verum acupuncture to decrease stress.

Trial registration number

ISRCTN15259166.

Introduction

In Western societies today a high percentage of people are experiencing increased or chronic

stress. The demands of work and the private lives of adults are often challenging and require

considerable effort to sustain [1]. It is well-known that chronic stress is a risk factor (or intensi-

fier) for a variety of physical disorders or illnesses [2, 3]. Chronic stress has been demonstrated

to increase cardiovascular risks, musculoskeletal disorders, and mental disorders such as

depression [4, 5]. There is a large body of literature examining increased stress levels of the var-

ious professions [6, 7]. In many professions, the prevalence of burnout as a possible conse-

quence of chronic stress is increasing [8–10]. In light of a highly stressed and unbalanced

working society the importance of short and effective treatment to reduce stress is undeniable.

Acupuncture, a part of the Traditional Chinese Medicine (TCM), has long been used as a

treatment for stress-related disorders. It is a more than a 2000 year old empirical medicine

whose efficacy for the treatment of various disorders such as low back pain and knee osteoar-

thritis has been confirmed [11–14]. In persons with chronic stress the balance between the

sympathetic and parasympathetic nervous system is disturbed [5]. Basic research regarding the

central effects of acupuncture showed that acupuncture is able to balance the sympathetic

(activating) and parasympathetic (regenerating) parts of the vegetative nervous system [15,

16]. Chen and Liu found that acupuncture can indeed improve the symptoms of adrenal insuf-

ficiency as well as influence the regulation and regeneration of the sexual and adrenal glands.

Beissner et al. [17] demonstrated that the needling sensation–the DeQi—activated the central

autonomic network of the hypothalamus, periaquaeductal grey, and medulla. As shown by

Mehta et al. [18], a series of acupuncture treatments over a longer period of time resulted in an

increased activity of parasympathetic functions. These effects are consistent with the hypothe-

sis that TCM acupuncture causes autonomic remodeling, most likely by reducing the sympa-

thetic activity and increasing the parasympathetic.

To date, a few studies have shown that acupuncture may serve as treatment for persons

with increased stress [19, 20]. However, well-designed randomized-controlled (RCT) studies

demonstrating the efficacy of acupuncture in chronic stress are still lacking. The present study

was a randomized-controlled pilot trial for adult persons with increased stress levels. The aim

of the study was to determine the feasibility of implementing a verum acupuncture interven-

tion (VA) versus a sham acupuncture treatment and as well as a wait list control condition

(WLC). The second aim was the estimation of possible effect sizes at the end of treatment.

Materials and methods

Study design and participants

AkuRest was a randomized controlled pilot trial of adult persons with increased stress levels.

The study was conducted at the University Hospital of Heidelberg and the University Hospital

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General Internal Medicine. There was no additional

external funding received for this study. The

funders had no role in study design, data collection

and analysis, decision to publish, or preparation of

the manuscript.

Competing interests: The authors declare that they

have no competing interests.

of Tübingen. Between September, 2017 and August, 2018 we included 70 participants. Inclu-

sion criteria were a Perceived Stress Questionnaire (PSQ) Score� 60, age� 18 and written

informed consent. Exclusion criteria were suicidal ideation, psychiatric disorder, needle pho-

bia, and insufficient knowledge of the German language. We are aware that there are more fac-

tors that could interfere with stress levels. However, inclusion and exclusion criteria for the

study were reduced to a minimum because we wished to show that acupuncture treatment

would be feasible in general for the group of persons with high stress levels.

The trial was approved by the independent ethics committees of the universities Heidelberg

(February, 2017) and Tübingen (July, 2017). It was registered in advance at http://www.isrctn.

com/, number ISRCTN15259166. The authors confirm that all ongoing and related trials for

this intervention are registered.

Sample size

The sample size calculation was based on the confidence interval approach from Cocks & Tor-

gersen [21] and the assumption that an effect size of 0.4 (regarding the stress level at the end of

treatment) between the verum and sham acupuncture would be clinically relevant. A sample

size of n = 42 would produce an upper limit of a one-sided 90%-interval that excludes 0.4,

assuming that the treatment estimate of the pilot study was zero or less [21]. However, with a

loss-to-follow up rate of about 16% a sample size of n = 50 (= 2 x 25) participants was needed

for the verum and the sham acupuncture group. An additional n = 25 participants were added

to the waiting control group, resulting in n = 75 participants for the pilot trial.

Randomization and masking

Participants were randomized to one of three groups. Randomization was performed by using

a stratified permuted block design with blocks of size n = 25 and centre as stratification vari-

able. Randomization was conducted by using the randomization software “RANDI2”[22]. The

randomization program was applied by an independent assistant at the University Hospital

Heidelberg; data analysts were blinded to the assignment. Participants who were randomized

to either the verum or the sham acupuncture group were blinded to treatment assignments

that is, they did not know whether they were receiving verum or sham acupuncture.

Treatments

The intervention is reported according to the STRICTA guidelines [23]. The acupuncture

treatment consisted of 10 sessions. Each session was from 20–30 minutes in length) and con-

sisted of approximately a 5 minutes consultation, 5 minutes needle insertion, and 20 minutes

needle retention time. Intervals between treatments varied from 3 to 7 days. However, accord-

ing to feasibility and the situation of the participants (e.g. holidays or illness) longer intervals

between treatments were allowed. Acupuncture was performed by two medical doctors with

an additional specialization in acupuncture provided by the medical association of Baden-

Wuerttemberg, Germany (a minimum 200 teaching units required). Each acupuncturist had

more then 10 years of experience in the field of acupuncture and traditional Chinese medicine.

For all acupuncture sessions, sterile, silicone coated, single-use filiform acupuncture needles,

with a length of 25 mm and a diameter of 0.25 mm each, were used. The manufacturer brand

was not defined. For the verum acupuncture a semi-standardized protocol was defined in a

consensus process between the acupuncturist and the study investigators, according to litera-

ture research, clinical expertise of the acupuncturists and results from previous studies [19].

For both groups traditional Chinese medicine acupuncture style was used. The acupuncture

treatments were performed in an outpatient clinic of the participating university clinics. Based

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on the information given by Brinkhaus et al. [24] in a previous trial patients were informed

about the types of acupuncture interventions in the study as follows: ‘‘In this study, different

types of acupuncture will be compared. One type is performed according to the principles of

traditional Chinese medicine; the other type does not follow these principles, but has also been

associated with positive outcomes in clinical studies”.

To ensure the adherence to the standardized protocol both acupuncturists were

continuously in contact with the study coordinators in Heidelberg and Tübingen. How-

ever, there were no site visits to ensure that they were following the standardized

procedure.

For verum acupuncture three points were fixed (Shenmen HT7 und Taixi KI3 needled bilat- erally, and Neiguan PC6 unilaterally) and maintained throughout the 10 sessions. These points were chosen according Chinese medicine theory in order to address the diagnostic patterns of

Shaoyin and Jueyin syndromes which are frequently presented in persons with increased stress

levels. Furthermore the selection of these acupuncture points is supported by preliminary evi-

dence describing a potential influence on the regulation of stress [19, 25, 26]. In addition to the

three fixed acupuncture points up to four points could be individually selected by the acupunc-

turist (with a maximum of 7 acupuncture points and 12 needles in total). The individual points

could be chosen and altered during the course of treatment by the acupuncturist in accordance

with the participants’ main clinical symptoms. In the verum acupuncture treatment depth of

insertion was point-specific with the aim of eliciting a De Qi; after achieving De Qi no further

needle stimulation techniques were applied. No other interventions (e.g. moxibustion, cup-

ping, life style advice) were administered to the acupuncture groups.

The active control condition for the verum acupuncture was a sham acupuncture treat-

ment. For the sham acupuncture, 4 to 6 standardized points which were not located on acu-

puncture meridians were chosen for acupuncture in a consensus process between the

acupuncturist and the study investigators (non-acupuncture points). These points were nee-

dled only superficially, that is, without eliciting the so-called De Qi sensation; the control acu-

puncture points could be changed individually during the course of treatment similar to the

verum acupuncture (maximum 12 needles). Further needling details and treatment regimen

did not differ from the verum acupuncture treatment.

Participants in the waiting control group received no acupuncture treatments over the

course of three months, after which they were offered a verum acupuncture treatment. We

chose this procedure for the control group to enhance the participant’s motivation for the

study and to prevent premature drop-outs.

Outcome measures

For all participants, diagnostic assessments were done at T0 (baseline, after inclusion and

before randomization), T1 (at the end of treatment or waiting time), and T2 (three months fol-

low-up for the verum and sham groups; end of treatment for the waiting list group). At the

three time points participants completed a study questionnaire. In addition, heart rate variabil-

ity was recorded and blood and urine samples were taken.

The main aim of the pilot study was to assess the feasibility and acceptability of the study

protocol. Feasibility and acceptability were assessed by means of the recruitment rate (propor-

tion of eligible persons and included persons), the study dropout rate (defined as proportion

of randomized patients to patients with incomplete data at T1 or T2), and completer rates.

In addition, effect sizes for verum and sham acupuncture were estimated at end of treat-

ment and at follow-up regarding the reduction of stress levels and possible improvement in

further psychosocial or endocrinologic parameters.

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The main instrument for measuring stress was the Perceived Stress Questionnaire (PSQ-

20) that aims to measure the subjective perception, appraisal, and processing of stressors [27,

28]. The questions are non-specific and can be interpreted to various situations (e.g. “You feel

under pressure from deadlines”) [29]. The questionnaire queries stressful feelings and experi-

ences over the course of the last month and shows a dimensional structure of four factors:

“worries, tension, joy, and demands” [30]. On a scale from 1 (“almost never”) to 4 (“usually”),

participants indicate how frequently they experience stress-related feelings or situations. A

total score is obtained by a specific algorithm that transforms the raw score to a scale that

ranges from 0–100. A PSQ-score� 60 indicates a high stress level. The PSQ-20 has been used

in various settings and has shown a sensitivity to change [28]. In addition to the PSQ-20, we

applied the stress module of the Patient Health Questionnaire [31].

Depressive symptoms were assessed using the 9-item depression module of the Patient

Health Questionnaire (PHQ-9) [32]. The PHQ-9 asks for cognitive, affective, and somatic

depression symptoms; each item corresponds to one of the nine DSM-IV diagnostic A-criteria

for a major depressive disorder; each item ranges from 0 to 3.

Somatic symptom severity of the participants was assessed using 13 items from the PHQ-15

questionnaire that is comprised of 15 somatic symptoms (stomach pain, back pain, etc.) each

symptom is scored from 0 to 2 [33]

The Generalized Anxiety Disorder Scale (GAD-7) was applied to assess the symptom sever-

ity of GAD; the total score of the GAD-7 ranges from 0 to 21. The German version of the

GAD-7 proved to be a reliable and valid instrument for screening for GAD [34, 35].

The Measure Yourself Medical Outcome Profile (MYMOP) is a four-item instrument that

allows patients to name up to two symptoms that are most concerning to them, and to assess

the change of these symptoms over time [36]. A profile score can be calculated by using the

mean of the four ratings for the most important self-reported symptom. A higher profile score

reflects a higher symptom burden.

Health-related quality of life was measured by the visual analogue scale (VAS) of the EQ-

5D. The EQ-VAS records the respondent’s self-rated health on a vertical VAS ranging from 0

to 100 where the endpoints are labelled “worst imaginable health state” (0) and”best imagin-

able health state” (100) [37]

For the determination of cortisone and cortisol levels, the first morning urine of the partici-

pants was collected and frozen until further analysis. The content of cortisone and cortisol in

these samples was determined by Ultra Performance Liquid Chromatography (Waters

ACQUITY UPLC) followed by tandem-mass spectrometry (LCMSMS, Ganzimmun).

Statistical analysis

The feasibility of the study was measured descriptively using percentages. Mean values and

standard deviations per group were calculated for the various variables and measurement time

points. Repeated measurement ANOVAs were run to compare the three groups at T0 and T1.

According to the Bonferroni-Holm-Shaffer method we applied pairwise t-tests (for T1 values)

whenever the global F-test showed a p-value < 0.05. For T2, we only compared the two verum

and sham acupuncture groups due to the fact that between T1 and T2 the waiting control

group received verum acupuncture and could thus not serve as a control group at T2. For T2

we applied t-tests for change scores to analyse the differences between the verum and sham

groups.

In addition, Cohen’s effect sizes for T1 were estimated together with their confidence inter-

vals, to illustrate the differences between groups. For T2, effect sizes were calculated for the

comparison between the verum and sham treatments only- as the waiting control group could

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not serve as a control group at T2. Effect sizes were calculated only for participants with com-

plete data.

To explore the heterogeneity across the two study centres additional ANOVAs for T1-T0

and T2-T0 change scores (PSQ-20, PHQ stress, depressive symptoms, and anxiety) were con-

ducted with treatment arm (verum vs. sham), centre, and treatment x centre as factors. All

analyses were done by using the statistics software SAS, version 9.4.

Results

Participant characteristics

Following an advertisement and distribution of fliers for the study N = 126 persons contacted

the study centers in Heidelberg and Tübingen who were interested in participating in the trial.

Of these 126 persons n = 70 (55.6%) met the eligibility criteria and were included in the study.

At the end of treatment (or waiting time) 11 participants (15.7%) were lost to follow-up. The

trial flow of the participants is shown in Fig 1.

Table 1 shows the baseline characteristics of the 70 study participants included in the pilot

trial.

The overall mean PSQ-20 score of 75.5 at baseline reflects the high stress level of the

included participants. Participants also showed high mean values in depression and anxiety

severity at baseline.

Overall, the participants showed a high compliance with the treatment protocol. N = 58

(82.9%) completed 100% (= 10 acupuncture sessions); 3 persons completed at least 80% of

their treatment while N = 7 participants did not start the acupuncture sessions due to various

reasons such as an accident or inaccessibility.

Specifically, 16 participants from the waiting list group received verum acupuncture

between T1 and T2 (84.2%). Of these, 15 completed 100% of their treatment.

No serious adverse events attributable to trial participation were recorded.

Effect sizes of stress related variables

Table 2 illustrates the mean values for the PSQ-20 and additional stress-related variables for

the three groups at the various measurement time points.

Results of the ANOVAs using T0 and T1 repeated measurements indicated a significant

change over time for all variables. In addition, for all variables except the PHQ stress module

the group x time interaction showed a p-value < 0.05. Subsequent t-tests revealed that the

verum and sham acupuncture groups showed better outcomes compared to the waiting list

group.

In 2005, Fliege et al. [28] had published mean values and standard deviations of various

patient groups and a group of healthy persons. The group of n = 334 healthy adults showed a

mean PSQ-20 score of 33 (± 17). If we define “clinically significant change” as being within two standard deviations from the mean of the functional or healthy group [38] then a post-

treatment mean score< 67 would indicate a clinically significant change for the “dysfunc-

tional” population (i.e. the participants with initially high stress levels). Interestingly, the wait-

ing control group still showed a mean stress level above this cut-off after the waiting period

whereas the mean levels of the verum and sham acupuncture groups were below this cut-off,

both at the end of treatment and at follow-up. In addition, the mean stress score of the “waiting

group” also dropped below this cut-off after having received the verum acupuncture treatment

(T2).

Fig 2 graphically displays the changes in PSQ-20 stress scores of the three groups over the

three measurement time points.

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Table 3 shows the various effect sizes at the end of treatment or waiting time together with

their confidence intervals.

The effect size for the comparison between verum and sham regarding the PSQ-20 score at

T1 was estimated with- 0.44 (95%CI = [-1.05. 0.16]). This effect size could be used for the sam-

ple size calculation of a following larger RCT. Assuming a two-side significance level of 0.05

and a power of 80% to prove the efficacy of verum acupuncture compared to sham

Fig 1. Trial flow of the participants.

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acupuncture one would have to include n = 166 participants in a larger two-arm RCT. With a

loss-to-follow-up rate of about 16% n = 198 participants should be included in a two-arm RCT

study.

Table 4 shows the effect sizes of the comparison between the verum and sham treatments at

the three-month follow-up (T2).

Apart from somatoform complaints, effect sizes of all variables are in favour of the verum

group. However, confidence intervals and t-tests show that these effect sizes were not

significant.

Heterogeneity among study centres

Additional analyses were run to explore the heterogeneity of the two study centres. These anal-

yses included only the verum and the sham group because change scores at T1 and T2 were

investigated. Results of the ANOVA regarding PSQ-20 change scores revealed no differences

between study centers regarding T1-T0 change scores in stress. However, for the T2-T0 change

scores in stress a significant interaction between centre and treatment arms (F1,37 = 5.12,

p = 0.03) was found. Subsequent t-tests indicated that in one centre (but not in the other), the

T2 stress level of the verum group had significantly improved compared to the sham group.

Additional centre-specific ANOVAs regarding change scores in depression, anxiety, and stress

levels measured by the PHQ stress module did not indicate different results for the two

centres.

Table 1. Baseline characteristics of the study participants.

Participants Heidelberg Participants Tübingen Participants in both study centers

(n = 41) (n = 29) (n = 70)

Demographic characteristics

Age (MW ± Std) 43.4 ± 13.2 52.1 ± 9.6 47.0 ± 12.5 Sex (n; %)

male 12 (29.3) 7 (24.1) 19 (27.1) female 29 (70.7) 22 (75.9) 51 (72.9)

Marital status (n; %)

single 19 (46.3) 7 (24.1) 26 (37.1) married 17 (41.5) 16 (55.2) 33 (47.1) divorced / widowed 5 (12.2) 6 (20.7) 11 (15.7)

Education (years) (n; %)

� 9 3 (7.3) 6 (20.7) 9 (12.9) 10–11 7 (17.1) 5 (17.2) 12 (17.1) � 12 29 (70.7) 18 (62.1) 47 (67.1) Other 2 (4.9) 0 (0.0) 2 (2.9)

Clinical characteristics

PSQ-20 Screening Score (MW ± Std) 73.9 ± 8.5 70.9 ± 7.9 72.6 ± 8.3 PSQ-20 Baseline Score (MW ± Std) 74.3 ± 7.8 77.3 ± 8.6 75.5 ± 8.2 EQ-5D (Visual analogue scale) (MW ± Std) 65.2 ± 20.9 64.2 ± 15.0 64.8 ± 18.6 Depression severity (PHQ-9) (MW ± Std) 10.8 ± 4.5 12.0 ± 4.8 11.3 ± 4.6 Anxiety severity (GAD-7) (MW ± Std) 9.8 ± 4.3 11.5 ± 4.8 10.5 ± 4.5

PSQ-20 = Perceived Stress Questionnaire; GAD-7 = Generalized Anxiety Disorder Scale; PHQ-9 = Patient Health Questionnaire

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Table 2. Mean values for the PSQ-20 and further stress-related variables at three time points.

(v) Verum acupuncture

T0: n = 25 T1: n = 21 T2:

n = 21 mean (s.d.)

(s) Sham acupuncture T0:

n = 26 T1: n = 22 T2:

n = 22 mean (s.d.)

(w) Waiting control

group T0: n = 19 T1:

n = 16 T2: n = 16 mean

(s.d.)

Contrast for T1-T0

scores (v)–(s) t-

value (df) p-value

Contrast for T1-T0

scores (v)–(w) t-

value (df) p-value

Contrast for T1-T0

scores (s)–(w) t-

value (df) p-value

PSQ-20 (T0) 75.2 (8.2) 76.7 (9.2) 74.3 (6.9) -1.41 (41) -4.1 (35) -3.4 (38)

PSQ-20 (T1) 46.5 (19.5) 55.2 (13.2) 68.0 (11.4) 0.17 0.0002 0.002

PSQ-20 (T2) 51.6 (21.5) 58.2 (13.3) 46.7 (12.7)

PHQ stress

module (T0)

8.5 (3.8) 8.7 (4.6) 7.7 (3.6) -0.20 (41) -2.34 (35) -1.6 (38)

PHQ stress

module (T1)

5.3 (3.6) 6.2 (3.9) 6.6 (3.4) 0.84 0.03 0.11

PHQ stress

module (T2)

5.8 (4.) 7.0 (2.9) 4.3 (2.3)

Depression

severity (T0)

11.6 (4.4) 11.8 (4.4) 10.2 (5.3) -0.19 (41) -3.05 (35) -2.93 (38)

Depression

severity (T1)

5.6 (2.9) 6.0 (3.7) 8.1 (4.3) 0.85 0.004 0.006

Depression

severity (T2)

6.5 (3.3) 7.0 (3.0) 4.8 (2.3)

Generalized

anxiety (T0)

11.6 (4.9) 10.0 (4.2) 9.6 (4.4) -1.46 (41) -3.08 (34) -1.99 (37)

Generalized

anxiety (T1)

5.7 (3.1) 5.2 (3.6) 8.4 (4.4) 0.15 0.004 0.05

Generalized

anxiety (T2)

5.9 (4.1) 5.9 (3.7) 4.8 (2.6)

Somatic

complaints

(T0)

6.4 (4.2) 8.6 (4.9) 6.5 (3.1) 0.11 (41) -3.08 (35) -2.75 (38)

Somatic

complaints

(T1)

3.6 (3.0) 5.7 (3.3) 6.9 (3.4) 0.92 0.004 0.009

Somatic

complaints

(T2)

4.7 (3.9) 5.9 (3.2) 5.1 (2.9)

Quality of life

(T0)

65.3 (18.3) 62.2 (21.1) 67.6 (15.5) -0.00 (40) 2.28 (34) 2.44 (38)

Quality of life

(T1)

79.6 (12.9) 73.7 (12.8) 66.1 (15.0) 0.99 0.03 0.02

Quality of life

(T2)

77.3 (10.4) 73.1 (16.1) 76.8 (9.6)

MYMOP

Profile (T0)

4.0 (0.7) 3.9 (1.2) 3.7 (0.7) -1.02 (40) -3.42 (33) -2.57 (37)

MYMOP

Profile (T1)

2.8 (0.9) 3.1 (1.2) 3.7 (0.9) 0.31 0.002 0.01

MYMOP

Profile (T2)

3.1 (1.4) 3.3 (1.2) 3.0 (0.8)

In the verum and sham acupuncture groups T1 is the end of the treatment and T2 is a three-month follow-up after the end of treatment. In the waiting control group T1

is the end of the waiting time and T2 the end of verum acupuncture treatment. Repeated measurement ANOVAs comparing the three groups showed p-values<0.05 for

the time x group interaction for all variables except the PHQ stress module. The Table presents the t- and p-values of subsequent contrasts

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Biological parameters

Table 5 shows the mean values of cortisol and cortisone measured in the urine samples. All of

the corresponding effect sizes (not shown) had confidence intervals that included the Zero,

indicating that the differences between groups would not be significant.

Discussion

This study demonstrates the feasibility of a three-arm randomized controlled trial for adults

with increased stress levels by comparing verum with sham acupuncture and a wait list control

condition.

Fig 2. Changes in stress levels over time.

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Table 3. Change scores and effect sizes for the PSQ-20 plus additional stress-related variables at T1.

Verum Sham Waiting control Verum vs. Waiting control Verum vs. sham Sham vs. waiting control

Change score(T1-T0) Mean value (STD) Mean value (STD) Mean value (STD) Effect size (95% CI) Effect size (95% CI) Effect size (95% CI)

PSQ-20 -30.6 (20.7) -22.7 (15.8) -7.0 (12.5) -1.39 (-2.11; -0.67) -0.44 (-1.05; 0.16) -1.12 (-1.78; -0.44)

PHQ stress module -3.2 (2.6) -3.0 (3.7) -1.4 (2.1) -0.79 (-1.46; -0.12) -0.06 (-0.66; 0.54) -0.53 (-1.17; 0.10)

Depression severity – 6.4 (4.5) – 6.1 (4.6) – 1.9 (4.4) -1.0 (-1.72;- 0.35) -0.06 (-0.66; 0.54) -0.96 (-1.62; -0.30)

Anxiety severity -6.7 (4.4) -4.7 (4.4) -1.4 (5.9) -1.06 (-1.76; -0.36) – 0.46 (-1.06; 0.15) -0.67 (-1.32; -0-02)

Somatic complaints -3.1 (3.3) -3.2 (4.2) 0 (2.6) -1.05 (-1.73; -0.36) 0.03 (-0.57; 0.63) -0.90 (-1.56; -0.24)

Quality of life 13.4 (15.6) 13.4 (15.1) 0.53 (18.3) 0.78 (0.10; 1.46) -0.01 (-0.61; 0.61) 0.80 (0.15; 1.45)

MYMOP Profile Score -1.34 (1.2) -0.98 (1.1) -0.05 (1.1) -1.19 (-1.91; -0.47) -0.32 (-0.94; 0.29) -0.86 (-1.52; -0.19)

All of the effect sizes comparing the verum group with the waiting list group at T1 favoured the verum acupuncture (with confidence intervals not including 0).

Regarding the stress level measured by the PSQ-20, the effect size was large (-1.39), in favour for the verum group. The comparison between sham treatment and waiting

group also resulted in effect sizes favouring the sham intervention–except for the PSQ-stress module. However, the effect sizes were smaller than those in favour for the

verum group; effect sizes comparing the verum versus the sham group at T1 were not significant.

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The response to the advertisements of the study showed that in general there is a high inter-

est in acupuncture treatment. For our study, the number of eligible participants was restricted

due, primarily, to the required high stress level at baseline (PSQ-20 score� 60). Nevertheless,

we were able to include n = 70 participants in the course of a recruitment period of 11 months,

thereby almost reaching the planned sample size of n = 75. All included participants were will-

ing to be randomized to one of the three study arms.

Adherence and drop-out rates of the study show that the design and treatment protocol

were, in fact, feasible and well accepted. The lost to follow-up rate was low (15.7%) and partici-

pants showed a high compliance with the treatment protocol.

The proposed outcome measure–the total score of the PSQ-20—appears to be appropriate

for measuring the efficacy of the acupuncture intervention. The items of the PSQ-20 represent

the subjective perspective of the individuals; they do not list specific worries, but rather ask

whether a person feels under pressure because of them (Levenstein, 1993). Results of our study

emphasize that the PSQ-20 score is sensitive to change.

The pilot study provides an estimation for the standard deviations and mean values of the

secondary outcome measures. These parameters can be used for the sample size calculation of

a later larger RCT. According to the estimations from this pilot trial a a following RCT should

include n = 198 participants to prove the efficacy of verum compared to sham acupuncture

regarding stress reduction.

Mean values in PSQ-20 stress levels (as well as depression and anxiety severity) were high at

baseline. Due to the high cut-off requirements for admission to the study, the standard devia-

tion of the PSQ-20 was relatively small at the beginning, but increased over time.

Table 4. Change scores and effect sizes for the PSQ-20 and additional stress-related variables at T2—Comparison between verum and sham group.

Verum Sham Verum vs. sham t-test for T2-T0 change score verum vs. sham

Change score(T2-T0) Mean value (STD) Mean value (STD) Effect size (95% CI) t-value (df) p-value

PSQ-20 -25.5 (22.6) -19.5 (15.7) -0.31 (-0.93; 0.30) -0.99 (33) 0.33

PHQ stress module -2.9 (2.9) -2.0 (2.8) -0.34 (-0.95; 0.28) -1.05 (33) 0.30

Depression severity -5.6 (4.8) -4.8 (3.8) -0.18 (-0.79; 0.44) -0.55 (39) 0.58

Anxiety severity -6.6 (4.8) -4.1 (4.8) -0.52 (-1.14; 0.1) -1.63 (39) 0.11

Somatic complaints -1.8 (3.7) -2.8 (4.0) 0.28 (-0.33; 0.90) 0.88 (39) 0.39

Quality of life (EQ-5D) 14.5 (15.7) 12.6 (14.2) 0.13 (-0.48; 0.74) 0.40 (39) 0.69

MYMOP Profile Score -1.1 (1.6) -0.77 (1.3) -0.23 (-0.86; 0.39) -0.01 (38) 0.99

Negative changes in PSQ-20, PHQ stress, and the other variables indicate improvement. In quality of life, positive changes indicate improvement

Effect sizes for comparison with the waiting group at T2 were not computed because at this time point, the waiting list group had already received verum acupuncture

treatment.

https://doi.org/10.1371/journal.pone.0236004.t004

Table 5. Mean values of cortisol and cortisone measured in urine samples at baseline, T1, and T2.

(mg / g Kreatinine) Verum acupuncture (n = 18) Sham acupuncture (n = 19) Waiting control group (n = 13)

Mean value (STD) Mean value (STD) Mean value (STD)

Cortisol (T0) 43.2 (23.3) 42.5 (20.3) 33.7 (16.7)

Cortisol (T1) 33.5 (22.9) 37.0 (23.4) 37.7 (29.8)

Cortisol (T2) 37.4 (16.7) 39.3 (22.6) 39.4 (27.4)

Cortisone (T0) 121.9 (53.7) 112.9 (49.6) 111.4 (56.7)

Cortisone (T1) 94.6 (50.9) 105.2 (56.0) 113.7 (56.8)

Cortisone (T2) 96.0 (39.8) 111.5 (48.2) 117.4 (67.9)

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In our pilot study the estimation of effect sizes at T1 showed that both verum and sham acu-

puncture were superior to the waiting condition in reducing stress levels. In comparison to the

waiting list group effect sizes at T1 were consistently higher for all variables in the verum

group than in the sham group. For the PHQ stress module, the effect size comparing verum

acupuncture to the waiting list condition was significant, whereas the effect size for sham acu-

puncture was not. In addition, effect sizes when comparing verum and sham acupuncture at

T2 were all (apart from one) in favour of the verum acupuncture. These effect sizes were not

significant, however, possibly due to the small sample size.

When interpreting the effect sizes of comparing verum to sham acupuncture one must take

into account that sham acupuncture is a complex control treatment. It is not comparable to

placebo pills as it differs regarding the aspects of physiological response and blinding efficacy

[19, 39]. Sham acupuncture can involve non-specific elements such as expectations of the par-

ticipants, possible relaxation time-out during the sessions, or the therapeutic relationship.

However, sham acupuncture can also induce specific effects from the needling; even when the

needling points are chosen outside the meridians (non-acupoints) the needle’s insertion can

excite local mechanisms of biochemical and biophysical reactions and thus have an impact on

the energy system [40]. Small-scale studies that compared verum to sham acupuncture there-

fore very rarely reach significance [19, 41]. Larger RCTs are therefore required to prove the dif-

ferences between the verum and sham acupuncture treatment.

Regarding the efficacy of acupuncture in stress reduction, the results of our pilot-study

expand upon the evidence of the few previous RCTs that exist. Huang et al. [19] found that in

n = 18 persons with increased stress levels the verum acupuncture group significantly

improved in the MYMOP profile (pre-post comparison); however, differences in the stress

scores did not reach significance due to the very small study sample. In a three-arm RCT that

included n = 120 patients suffering from psychological distress Arvidsdotter et al. [20] showed

that verum acupuncture and integrative treatment were significantly better than conventional

treatment in all outcome variables. Regardless, the study included patients with a psychiatric

diagnosis (such as depression and/or anxiety) but did not explicitly measure stress levels.

Using the Perceived Stress Scale as outcome measure, Schroeder et al. [42] reported that com-

pared to sham acupuncture, verum acupuncture resulted in a significantly greater reduction in

stress. However, of the initially n = 111 included participants with high self-reported stress lev-

els only n = 62 completed the study. Many participants had dropped out because they could

not maintain the required treatment schedule. In contrast, in the AkuRest study the treatment

protocol of the acupuncture intervention was clearly well accepted; only a few participants

dropped out of the intervention and very few acupuncture sessions were cancelled.

The high mean values and low standard deviations in the PSQ-20 scores at baseline reflect

the high stress levels of the participants when they entered the study. In the verum group the

mean value dropped below 50 at T1 and slightly increased to 51.6 at T2. Similarly, in the wait

list group, the PSQ stress mean value was highly decreased between the end of the waiting

period (T1) and the end of the verum acupuncture treatment (T2). The same pattern is also

apparent in all the other psychosocial–and endocrinologic–variables. In the verum group,

there was a strong improvement between baseline and end of treatment, and a slight decline

between end of treatment and follow-up. In the wait list group, there was a very small improve-

ment in all variables during the waiting period, followed by a substantial improvement at the

end of the verum acupuncture treatment.

The analyses regarding a possible heterogeneity among the two centres showed no differ-

ences in PSQ-20 change scores at T1. At T2, only one centre showed significantly improved

PSQ-20 scores for the verum group compared to sham. For further variables, no differences

between the two study centers were found. However, as the PSQ-20 score would be our

PLOS ONE Acupuncture pilot RCT in increased stress

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preferred primary outcome for a subsequent larger RCT we would recommend to stratify ran-

domization for centres and to include the centre factor in the outcome analysis.

Our pilot study has several limitations. Firstly, the design included a wait list control arm.

The advantage of this control condition is greater attractiveness for entering the study. After

the waiting period, 84.2% of the participants in the wait list wished to receive verum acupunc-

ture; the motivation to follow the treatment and measurement protocol was therefore high.

However, the disadvantage of this control condition is the lack of a control group for a longer

follow-up. As a result, we were not able to estimate the effect size of verum acupuncture versus no acupuncture treatment after a period of six months. For a larger RCT, it should be re-

thought whether or not a pure no-treatment control condition or a longer waiting period

would be preferable. Secondly, we see the problems associated with sham acupuncture as a pla-

cebo control treatment. However, we believe that with a larger sample size we would be able to

prove the efficacy of verum acupuncture in reducing stress levels compared to sham.

All in all, we can conclude from this pilot study that the treatment protocol of the AKuRest

study is feasible and well accepted by persons with high stress levels. Estimations of effect sizes

show that acupuncture treatment has a positive effect on stress reduction as well as other

health outcomes as compared to no treatment. In addition, results indicate that verum acu-

puncture could, in fact, be more effective than sham acupuncture in reducing stress levels.

However, to scientifically prove the efficacy of verum acupuncture as compared to sham acu-

puncture an RCT with a larger sample size should be conducted.

Supporting information

S1 Checklist. CONSORT 2010 checklist of information to include when reporting a pilot

or feasibility randomized trial in a journal or conference abstract.

(DOC)

S1 File.

(PDF)

S2 File.

(PDF)

S1 Data.

(XLS)

Author Contributions

Conceptualization: Beate Wild, Judith Brenner, Stefanie Joos, Yvonne Samstag.

Data curation: Magdalena Buckert.

Formal analysis: Beate Wild, Magdalena Buckert.

Funding acquisition: Stefanie Joos, Yvonne Samstag.

Investigation: Beate Wild, Judith Brenner, Stefanie Joos, Yvonne Samstag, Jan Valentini.

Methodology: Beate Wild, Judith Brenner, Magdalena Buckert.

Project administration: Beate Wild, Stefanie Joos, Yvonne Samstag, Jan Valentini.

Resources: Jan Valentini.

Software: Magdalena Buckert, Jan Valentini.

Supervision: Beate Wild, Judith Brenner, Stefanie Joos.

PLOS ONE Acupuncture pilot RCT in increased stress

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Validation: Beate Wild, Magdalena Buckert, Jan Valentini.

Writing – original draft: Beate Wild, Judith Brenner.

Writing – review & editing: Stefanie Joos, Yvonne Samstag, Magdalena Buckert, Jan

Valentini.

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