The long-term effect of acupuncture for patients with chronic tension-type headache: study protocol for a randomized controlled trial
Lu et al. Trials
The long-term effect of acupuncture for patients with chronic tension-type headache: study protocol for a randomized controlled trial
Lingyun Lu 0 2
Hui Zheng 0 2
Qianhua Zheng 0 2
Xinyu Hao 0 2
Siyuan Zhou 0 2
Shusen Zhang 0 2
Tao Wei 0 2
Tao Gao 0 2
Duoxi Duan 0 2
Ling Zhao 0 2
Ning Li 1
Ying Li 0 2
0 Chengdu University of Traditional Chinese Medicine , 37 Shi'er Qiao Road, Jinniu District, Chengdu, Sichuan 610075 , People's Republic of China
1 West China School of Medicine/West China Hospital of Sichuan University , 37 Guoxue Lane, Wuhou District, Chengdu, Sichuan 610041 , People's Republic of China
2 Chengdu University of Traditional Chinese Medicine , 37 Shi'er Qiao Road, Jinniu District, Chengdu, Sichuan 610075 , People's Republic of China
Background: The effectiveness of acupuncture for patients with chronic tension-type headache (CTTH) is controversial. In this article, we report the protocol for a randomized controlled trial aiming to evaluate the longterm effect of acupuncture for CTTH, in comparison with superficial acupuncture. Design: A two-armed, parallel-design, patient-assessor blind, randomized controlled trial is underway in China. A total of 218 participants with CTTH will be randomly assigned to the treatment group or the control group in a 1:1 ratio. Participants in the treatment group and control group will receive acupuncture or superficial acupuncture treatments in a fixed prescription of acupoints respectively, for a total of 20 sessions over 8 weeks. The posttreatment follow-up period will be 24 weeks. The primary outcome will be the proportion of responders assessed at week 16 after randomization. The secondary outcomes will include the number of headache days, the mean intensity of headache, the reduction of medication intake, results from the 36-item short form health survey, the Hamilton Depression Scale and the Hamilton Anxiety Scale, the number of participants with adverse events, the expectation value of acupuncture treatment, and the intensity of deqi sensation. The first five secondary outcomes will be assessed or calculated at baseline, and at 4, 8, 12, 16, 20, 24, 28, and 32 weeks after randomization. Moreover, the expectation value will be collected at baseline and at week 8 after randomization, the intensity of deqi sensation will be assessed at 5 minutes after each treatment and adverse events will be summarized at the end of the follow-up period. Discussion: Results from this trial will provide evidence for the long-term effect of acupuncture for CTTH with a long follow-up period. Trial registration: ClinicalTrial.gov NCT03133884. Registered on 25 April 2017.
Acupuncture; Chronic tension-type headache; Randomized controlled trial; Study protocol
Chronic tension-type headache (CTTH) is a disorder
evolving from frequent episodic tension-type headache
(TTH), typically bilateral, pressing or tightening in
quality, mild to moderate in intensity, lasting hours to days,
or unremitting [
]. In April 2016, the World Health
Organization reported that chronic headache, occurring
on 15 or more days every month affected 1.7–4% of the
world’s adult population, among which CTTH, as the
most common chronic primary headache disorder,
affected 1–3% of adults [
According to the guidelines developed by the European
Federation of Neurological Societies, prophylactic
treatment should be considered in patients with CTTH, and
the recommended prophylactic drugs include
amitriptyline, mirtazapine, venlafaxine, and muscle relaxants [
However, some unpleasant side effects of the
recommended drugs have been reported, including sexual
dysfunction, body weight changes, gastrointestinal
discomfort, unusual bleeding, and bruising [
]. In addition
to the serious adverse effects associated with the use of
muscle relaxants, its evidence for application to CTTH
patients is limited [
]. More importantly, issues such as
medication overuse and how to prevent CTTH sufferers
from developing medication overuse headache require
Acupuncture, one of the most important components
in traditional Chinese medicine (TCM), is widely used to
relieve tension-type headache [
]. Several trials of
good quality have drawn the conclusion that
acupuncture was superior to sham acupuncture in TTH
]; some studies, however, have indicated no
significant differences [
]. According to the
National Institute for Health and Clinical Excellence
clinical guidelines [
] and Cochrane Library systematic
], acupuncture is recommended for
CTTH management. Nevertheless, its scientific basis is
still relatively limited owing to a lack of adequate
statistical power, insufficient reports, or relevant
methodological shortcomings in previous studies [
CTTH is a chronic disorder characterized by
persistent or recurrent attacks of headaches, thus the
long-term effect of acupuncture is of particular
importance because of its instant effect in treatments.
Therefore, we have designed a randomized controlled
trial (RCT) with a 36-week observation period to
investigate and evaluate the long-term effect of
acupuncture for CTTH.
Method and design
This study is a parallel-design, patient-assessor blind
RCT comparing an acupuncture treatment group with a
superficial acupuncture control group. Two hundred
and eighteen patients with CTTH will be recruited
through but not limited to: reviewing and screening of
outpatients in the Teaching Hospital of Chengdu
University of Traditional Chinese Medicine, university
media releases, community advertisement including
distributing leaflets via regular community health
counselling, media campaigns, and network recruitment.
Eligible participants will be randomly assigned to the
acupuncture treatment group or the superficial
acupuncture control group with a 1:1 ratio. The total observation
period will be 36 weeks, including a 4-week baseline
period, an 8-week treatment period and a 24-week
follow-up period. They will receive 20 sessions of
acupuncture or superficial acupuncture treatment over
8 weeks (three sessions per week in the first 4 weeks and
two sessions per week in the following 4 weeks). During
the baseline, treatment and follow-up periods,
participants will not be allowed to take any prophylactic
medications (e.g., amitriptyline, clomipramine, and
mirtazapine) for CTTH, but will be permitted to use
necessary analgesics (e.g., ibuprofen, paracetamol and
ibuprofen) when headache is unbearable The type,
dose and time of administration will be recorded in
headache diaries. Assessments will be conducted at
baseline and at 4, 8, 12, 16, 20, 24, 28, 32, and
36 weeks after randomization. Figures 1 and 2
illustrate the time schedule of enrolment, interventions,
assessments, and visits of participants. The reporting
of this trial is conducted according to the Standard
Protocol Items: Recommendations for Intervention
Trials (SPIRIT) guidelines (Additional file 1).
The Consolidated Standards of Reporting Trials
] and the Standards for Reporting Interventions
in Clinical Trials of Acupuncture [
] have been
used as frameworks of methodology for designing
Study population and sample size
We will recruit CTTH sufferers who meet the diagnostic
criteria in the International Classification of Headache
Disorders, 3rd Edition (ICHD-3) formulated by the
International Headache Society [
]. According to a
previous study [
], the proportion of responders (at least
50% reduction in days with headache) was 46% after
acupuncture treatment versus 35% after superficial
acupuncture (odds ratio, 1.32). In this study, we expect an
odds ratio of 1.35 when acupuncture is compared with
superficial acupuncture. Assuming a significance level of
0.05, a study power of 0.8, and a correlation of 0.5
between independent variables (including study groups,
assessment intervals, and the number of headache days
at baseline), 199 participants are required to reject the
hypothesis that acupuncture is equivalent to superficial
acupuncture. Taking a 10% attrition bias into
consideration, we will recruit 218 participants in total, with 109
in each group.
Eligible participants should conform to ICHD-3
diagnostic criteria of CTTH and those who meet the following
inclusion criteria will be included: (1) aged 18–65 years;
(2) having TTH for more than 1 year; (3) suffering from
TTH for at least 15 days per month on average during
the previous 3 month; (4) able to complete the headache
diary; (5) agree to participate in this study and provide
written informed consent.
Participants meeting any of the following criteria will be
excluded: (1) headache is caused by other medical
disorders (e.g., subarachnoid hemorrhage, cerebral hemorrhage,
cerebral embolism, cerebral thrombosis, vascular
malformation, arthritis, hypertension, or arteriosclerosis); (2)
have taken prophylactic headache medication during the
previous 3 months; (3) suffering from neurological
diseases, mental disorders, immunodeficiency, bleeding
disorders, or allergies; (4) having any serious disease of the
heart, liver, kidney, or other organs; (5) those who are
pregnant or lactating, or plan to be pregnant in the next
36 weeks; (6) unwilling to take part in the study or with
low compliance, defined as the people who just plan to
receive up to ten sessions of a total of 20 treatment sessions;
(7) addicted to smoking, alcohol, or drugs; (8) involved in
other clinical studies at the same time.
Participants will be removed if they are unwilling to
continue this study, or fail to continue for at least 12
sessions of treatment.
Randomization, allocation concealment and blinding
The Brightech Clinical Information Management System
(CIMS) will be used for central randomization, which is
performed by Brightech Clinical Medicine Research Co.
Ltd. in Chengdu, China. Only authorized research
assistants can obtain random numbers and group assignment
information by logging into the CIMS website, which
can ensure the randomization will not be influenced by
researchers and patients. The randomization information
will be concealed in the server until the end of the trial.
It is not possible to blind acupuncturists in this trial,
therefore, they will not take part in the assessment
procedure. Participants in different groups will receive treatment
in different therapeutic rooms and be blinded to their
treatment allocations. After all the treatment sessions, they
will be asked to guess what kind of acupuncture treatment
they have received (acupuncture or superficial
acupuncture). Outcome assessors and statisticians will be blinded
to the treatment allocation.
Combining Chinese acupuncture experts’ opinions with
the results from data mining analysis of acupoints, a
standardized acupoints prescription consisting of Fengchi
(GB20), Baihui (GV20), Taiyang (EX-HN5), Hegu (LI4),
and Taichong (LR3) will be applied for CTTH treatment
in this trial (Table 1). Participants in both groups will
receive 20 sessions of acupuncture over 8 weeks (three
sessions per week in the first 4 weeks and two sessions per
week in the last 4 weeks). Acupuncturists who have at
least 5 years of professional training will receive training
classes before this trial. Contents of the training include
acupoint locating, needle manipulation skills, and
communication skills. The acupuncturists can participate in
the trial if they pass the trial training examination.
Acupuncture treatment group
All acupoints will be punctured by filiform needles
(sterile, disposable needles provided by Suzhou Hwato
Medical Instruments Co. Ltd., Suzhou, China) when
patients are in a comfortable sitting position. The needles
of 25 to 45 mm in length and 0.25 mm in diameter will
be inserted into the acupoints and the depths will be
adjusted to the standard permissible layers of each
acupoint. Then an even reinforcing-reducing technique,
which means lifting, thrusting, twisting, and rotating the
needles moderately, will be performed on the needles
until achieving the deqi sensation. The needles will be
retained for 30 minutes in each session and manipulated
every 10 minutes with intermittent stimulation for
maintaining the deqi sensation. The manipulation of each
acupoint will last for 10 seconds.
Superficial acupuncture control group
Participants in the control group will receive superficial
acupuncture using filiform needles on the same
acupoints as the treatment group. The depth of penetration
into the skin will be controlled to within 2 mm by
limited tubes, and the needles will be retained for 30
minutes without any manipulation to avoid the deqi
sensation as much as possible.
The following outcomes will be assessed by independent
assessors blinded to the allocation.
The primary outcome measurement is the proportion of
responders at week 16. A responder is defined as a
participant with a decrease of at least 50% less headache
days during 4 weeks. A participant with a reduction of
less than 50% headache days, including anyone with
missing data, is defined as a nonresponder. This
outcome measurement will be assessed at week 16 after
The secondary outcome measurements are (1) number
of headache days per 4 weeks, (2) the mean intensity of
headache recorded by visual analogue scale score and
grade of headache intensity per 4 weeks, (3) the
reduction of medication intake per 4 weeks, (4) the 36-item
short form health survey (SF-36) [
], (5) Hamilton
Depression Scale (HAMD) [
] and Hamilton Anxiety
Scale (HAMA) [
] results, (6) number of participants
with adverse events (AEs) and serious adverse events
(SAEs), (7) expectation values of acupuncture treatment,
(8) the intensity of the deqi sensation.
All participants will be asked to complete a daily
headache dairy and return them to assessors by emails, short
messages or telephone calls throughout the whole
36week observation period. The first three secondary
outcomes will be extracted from the headache diaries. And
the three outcomes followed will be assessed at each
visiting time point. All of the above outcome
measurements will be assessed at baseline, and at 4, 8, 12, 16, 20,
24, 28, and 32 weeks after randomization. Moreover, the
expectation value of acupuncture treatment will be
collected at baseline and week 8 after randomization, and
the intensity of the deqi sensation will be assessed at
5 minutes after each treatment using the Massachusetts
General Hospital Acupuncture Sensation Scale (MASS).
Details of AEs and SAEs will be documented during
the 36-week period, such as occurrence time, duration,
coping methods, and the correlation with treatment.
AEs include bleeding, hematoma, fainting, severe pain,
local infection, and so on, while SAEs are defined as
lifethreatening events, leading to significant or persisted
disability, resulting in or prolonging hospitalization.
Researchers responsible for recruiting participants and
assessors responsible for collecting data must receive
training to ensure all of them have the same standards
and understand the purpose, contents, and quality
control of the trial. Detailed time points of outcome
assessments are provided in Fig. 2.
Data collecting and monitoring
Data will be recorded on the paper version of case
report forms (CRFs) by designated outcome assessors, and
double entered in the electronic CRFs, which is
established and monitored by the Evidence-based Medicine
Center of Chengdu University of Traditional Chinese
Medicine. Monitors will audit the data every 3 months.
Acupuncturists and statisticians will have no access to
these data during the evaluating process.
Primary analysis will be based on intention-to-treat
population, including participants with at least one
assessment of the primary outcome and one acupuncture
session. Per protocol (PP) analysis will be performed to
test the robustness of the primary analysis. PP
population will include participants receiving at least 12
sessions of acupuncture and be assessed at week 8 and 16.
The primary outcome will be analyzed with a random
intercept logistic regression model, taking treatment
allocation as a random factor and taking sex, age, and
duration of headache as fixed factors. The secondary
outcomes (headache days, headache intensity, SF-36,
HAMA, HAMD results) will be analyzed using a
generalized least squares regression model, with the same
covariates as the primary outcome. For the rest of
outcomes, we will make pairwise comparisons using a
general linear model adjusted for baseline value, age,
sex, and disease course. Missing values of the primary
outcome will be imputed by the
last-observationcarried-forward method. We will run several sensitivity
analysis to ensure the robustness of the imputation: first,
lost-to-follow-up participants in the acupuncture group
will be recognized as nonresponders, whereas those in
the superficial acupuncture group will be recognized as
responders; second, lost-to-follow-up participants will be
counted as responders in the acupuncture group but
nonresponders in the superficial group; Third, all
lost-to-follow-up participants will be treated as
nonresponders. Missing values in the secondary outcomes
will be imputed by using the multiple imputation
method (n = 5).
All confidence intervals will be two-sided 95%
intervals comparing acupuncture to superficial acupuncture
and all statistical hypotheses will be two-sided tests.
Analyses will be performed using the R and Stata
Previous RCTs have been conducted to explore the
effect of acupuncture for TTH compared with no
], sham interventions (non-skin-penetrating
techniques or needling non-acupoints) [
9, 11–13, 16
other treatment (relaxation, massage, or physiotherapy)
], but the conclusions remain controversial. In
a recent Cochrane systematic review [
], seven of the
12 included trials recruited both episodic and chronic
TTH patients [
9, 11, 13, 23–26, 28
], which made it
relatively difficult to evaluate the effect of acupuncture for
CTTH separately and precisely. Three of the 12 trials
16, 17, 27
] included participants with CTTH only, but
their small sample sizes, various types of acupuncture
interventions, non-uniformed comparisons, and different
observation periods may lead to an uncertain evaluation
of acupuncture effect. Therefore, we designed a
twoarmed, parallel-design, patient-assessor blind, RCT to
explore and evaluate the long-term effect of acupuncture
for CTTH treatment. In this trial, we will compare
acupuncture with superficial acupuncture to clarify the
long-term therapeutic effect of acupuncture for CTTH.
In this trial, participants in different groups will
receive treatments in different rooms to block the
communication between the two groups and reduce patients’
doubts about different interventions. Moreover, all of
the acupuncture manipulations will be performed on the
fixed main acupoints by two trained acupuncturists who
have passed the special training examination, in order to
reduce the influence of participants’ psychological
factors on clinical effects. It is reported that negative mood
state has a close relationship with TTH [
Therefore, psychological assessments of participants
based on HAMA and HAMD are planned.
Furthermore, we will pay special attention to the recording
of the deqi sensation, which may enhance the
acupuncture effect as described in TCM classical works
and traditional acupuncture theory .
A placebo control plays a crucial part in evaluating the
effectiveness of a treatment, which can help separate the
specific and nonspecific effects and reduce bias by
enabling blinding. Therefore, being inert and
indistinguishable from the true intervention are the main
characteristics of a perfect placebo or a sham intervention.
However, to devise or find adequate placebos seems too
difficult for physical interventions, such as acupuncture.
Currently, superficial acupuncture is considered as a
type of sham acupuncture, because the needle depth
does not reach acupoints’ anatomical layers. However,
there is increasing evidence that sham acupuncture
might be associated with larger placebo effects than
pharmacological placebos [
], especially for some
subjective outcomes and the treatment of pain [
positive expectation of an intervention is an important
part of the placebo effect [
], which is also
supported by many previous trials [
]. In addition, a
good doctor-patient relationship also contributes to
patients’ expectations, which may increase placebo effects
after repeated treatments and harmonious
]. It may be the reason why no significant
differences of effects between acupuncture and sham
acupuncture were reported by several trials [
Hence, we will make a comparison of participants’
expectations between two groups to eliminate the impact
on our results.
A recent RCT reported that the acupuncture effect
can be maintained for 20 weeks after 20 sessions of
treatment over 4 weeks, which could be considered as
powerful evidence for the existence of a sustained effect
produced by acupuncture [
]. In addition, a systematic
review indicated that the placebo effect of acupuncture
showed a unique pattern according to time, which
increased from baseline to 12 weeks and decreased after
12 weeks [
]. Considering the necessity of a relatively
long observation period, we will conduct the trial over a
period of 36 weeks and make assessments every 4 weeks,
which aims to not only evaluate the long-term effect of
acupuncture for CTTH, but also distinguish curative
effects from placebo effects of acupuncture. However, the
long observation period has its limitations. It may
increase the rate of patient dropout and we will not know
if the patients receive other treatments in the follow-up
period. To minimize the potential bias, we formulate the
plan to reduce dropout by establishing good
communication relationships with participants and maintaining
close contacts via telephone calls, text messages and
emails during the follow-up period. Moreover,
characteristics of the dropouts will be extracted and analyzed,
which can help judge whether the results are affected by
In conclusion, the results of this trial are expected to
not only provide clinical evidence of the effectiveness of
acupuncture as a painkiller, but also evaluate the
duration and intensity of the acupuncture effect for CTTH.
The trial project commenced in early 2017. Recruitment
of participants is currently underway.
Additional file 1: SPIRIT 2013 checklist: recommended items to address
in a clinical trial protocol and related documents*. (DOC 124 kb)
AEs: adverse events; CRFs: Case report forms; CTTH: Chronic tension-type
headache; HAMA: Hamilton Anxiety Scale; HAMD: Hamilton Depression Scale;
ICHD-3: International Classification of Headache Disorders, 3rd Edition;
RCT: randomized controlled trial; SF-36: 36-item short form health survey;
SAEs: serious adverse events; SPIRIT: Standard Protocol Items:
Recommendations for Intervention Trials; TCM: Traditional Chinese medicine;
TTH: Tension-type headache
We would like to express gratitude to Prof. Yang Dongdong from the
Neurology Department of the Teaching Hospital of Chengdu University of
Traditional Chinese Medicine, Prof. Li Ji from the Acupuncture and Moxibustion
Department of the Teaching Hospital of Chengdu University of Traditional
Chinese Medicine, Prof Li Ning from the Department of Integrated Traditional
Chinese and Western Medicine of West China Hospital. We also appreciate the
support and efforts from people who have been or will be included in this
study. We appreciate the help of Dr. Yuan Ming Di with language editing.
This study is supported by the International Cooperation Program of Science
and Technology Department of Sichuan Province, China (No. 2016HH0007).
Availability of data and materials
LYL, HZ, LZ, QHZ, XYH, SYZ, LZ and YL participated in the conception and
design of this trial, and in plans for the data. LYL, QHZ, XYH and HZ were
responsible for planning the draft and revising the manuscript. LZ and YL are
monitors of this study. SSZ, TG, TW and NL are responsible for the recruitment
and/or treatment of patients. LYL and DXD are responsible for collecting the
data. All authors have read the manuscript and approved the publication of this
Ethics approval and consent to participate
The study is approved by Sichuan Regional Ethics Review Committee on
Traditional Chinese Medicine (Approval No. 2016KL-007), and registered with
ClinicalTrials.gov in the USA (NCT03133884). The implementation follows the
principles of the Declaration of Helsinki (Version Edinburgh 2000). Only participants
who provide written informed consent will be included in this study.
Consent for publication
The authors declare that they have no competing interests.
Springer Nature remains neutral with regard to jurisdictional claims in
published maps and institutional affiliations.
Submit your next manuscript to BioMed Central
and we will help you at every step:
1. International Headache Society. The international classification of headache disorders, 3rd edition (beta version) . Cephalalgia . 2013 ; 33 ( 9 ): 629 - 808 .
2. World Health Organization. Headache disorders fact sheet no 277 . WHO. 2016 . http://www.who.int/mediacentre/factsheets/fs277/en/. Accessed Apr 2016 .
3. Bendtsen L , Evers S , Linde M , et al. EFNS guideline on the treatment of tension-type headache - report of an EFNS task force . Eur J Neurol . 2010 ; 17 ( 11 ): 1318 - 25 .
4. Vanina Y , Podolskaya A , Sedky K , et al. Body weight changes associated with psychopharmacology . Psychiatr Serv . 2002 ; 53 ( 7 ): 842 - 7 .
5. Baldwin DS , Foong T. Antidepressant drugs and sexual dysfunction . Br J Psychiatry J Ment Sci . 2013 ; 202 ( 6 ): 396 - 7 .
6. U.S. National Library of Medicine. Amitriptyline hydrochloride tablet, film coated . 2013 . DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo. cfm?setid= 1e6d2c80 -fbc8 - 444e -bdd3-6a91fe1b95bd. Accessed 2 Feb 2017 .
7. Krishnan A , Silver N. Headache (chronic tension-type) . Clin Evid . 2009 ; 07 : 1205 .
8. National Institute for Health and Clinical Excellence. Headaches: diagnosis and management of headaches in young people and adults . London: National Clinical Guideline Centre; 2012 . https://www.nice.org.uk/guidance/ cg150, Accessed Sept 2012 .
9. Endres HG , Bowing GDiener HC , Lange S , et al. Acupuncture for tensiontype headache: a multicentre, sham-controlled, patient-and observerblinded, randomised trial . J Headache Pain . 2007 ; 8 ( 5 ): 306 - 14 .
10. Xue CC , Dong L , Polus B , et al. Electroacupuncture for tension-type headache on distal acupoints only: a randomized, controlled, crossover trial . Headache J Head Face Pain . 2004 ; 44 ( 4 ): 333 - 41 .
11. Melchart D , Streng A , Hoppe A , et al. Acupuncture in patients with tensiontype headache: randomised controlled trial . BMJ . 2005 ; 331 ( 7513 ): 376 - 82 .
12. White AR , Resch KL , Chan JC , et al. Acupuncture for episodic tensiontype headache: a multicentre randomized controlled trial . Cephalalgia . 2000 ; 20 ( 7 ): 632 - 7 .
13. Karst M , Reinhard M , Thum P , et al. Needle acupuncture in tension-type headache: a randomized, placebo-controlled study . Cephalalgia . 2001 ; 21 ( 6 ): 637 - 42 .
14. Linde K , Allais G , Brinkhaus B , et al. Acupuncture for tension-type headache . Cochrane Database Syst Rev . 2009 ; 21 ( 1 ): CD007587 .
15. Linde K , Allais G , Brinkhaus B , et al. Acupuncture for the prevention of tension-type headache . Cochrane Database Syst Rev . 2016 ; 4 ( 4 ): CD007587 .
16. Kwak BM , Kim MJ , Kim YM , et al. Persisting effects of acupuncture method for chronic tension-type headache; a randomized controlled trial . J Korean Acupunct Moxibustion Soc . 2008 ; 25 : 165 - 77 .
17. Söderberg E , Carlsson J , Stener-Victorin E . Chronic tension-type headache treated with acupuncture, physical training and relaxation training. Between-group differences . Cephalalgia . 2006 ; 26 ( 11 ): 1320 - 9 .
18. Schulz KF , Altman DG , Moher D , et al. CONSORT 2010 Statement: updated guidelines for reporting parallel group randomized trials . BMC Med . 2010 ; 8 ( 1 ): 18 .
19. Macpherson H , Altman DG , Hammerschlag R , et al. Revised STandards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA): extending the CONSORT statement . J Evid Based Med . 2010 ; 3 ( 3 ): 140 - 55 .
20. Jr WJ , Sherbourne CD . The MOS 36-item short-form health survey (SF-36). I. Conceptual framework and item selection . Med Care . 1992 ; 30 ( 6 ): 473 - 83 .
21. Williams JB . A structured interview guide for the Hamilton Depression Rating Scale . Arch Gen Psychiatry . 1988 ; 45 ( 8 ): 742 - 7 .
22. Shear MK , Vander BJ , Rucci P , et al. Reliability and validity of a structured interview guide for the Hamilton Anxiety Rating Scale (SIGH-A) . Depress Anxiety . 2001 ; 13 ( 4 ): 166 - 78 .
23. Jena S , Witt C , Brinkhaus B , et al. Acupuncture in patients with headache . Cephalalgia . 2008 ; 28 ( 9 ): 969 - 79 .
24. Tavola T , Gala C , Conte G , et al. Traditional Chinese acupuncture in tensiontype headache: a controlled study . Pain . 1992 ; 48 ( 3 ): 325 - 9 .
25. White AR , Eddleston C , Hardie R , et al. A pilot study of acupuncture for tension headache, using a novel placebo . Acupunct Med . 1996 ; 14 ( 1 ): 11 - 5 .
26. Ahonen E , Hakumaki M , Mahlamaki S , et al. Effectiveness of acupuncture and physiotherapy on myogenic headache: a comparative study . Acupunct Electrother Res . 1984 ; 9 ( 3 ): 141 - 50 .
27. Carlsson J , Fahlcrantz A , Augustinsson LE . Muscle tenderness in tension headache treated with acupuncture or physiotherapy . Cephalalgia . 1990 ; 10 ( 3 ): 131 - 41 .
28. Wylie KR , Jackson C , Crawford PM . Does psychological testing help to predict the response to acupuncture or massage/relaxation therapy in patients presenting to a general neurology clinic with headache ? J Tradit Chin Med . 1997 ; 17 ( 2 ): 130 - 9 .
29. Song TJ , Cho SJ , Kim WJ , et al. Anxiety and depression in tension-type headache: a population-based study . PloS One . 2016 ; 11 ( 10 ): e0165316 .
30. Valença MM . Commentary: acute tension-type headaches are associated with impaired cognitive function and more negative mood . Front Neurol . 2016 ; 7 ( 6 ): 103 .
31. Yuan HW , Ma LX , Qi DD , et al. The historical development of deqi concept from classics of traditional Chinese medicine to modern research: exploitation of the connotation of deqi in Chinese medicine . Evid Based Complement Alternat Med . 2013 ; 2013 : 639302 .
32. Linde K , Niemann K , Meissner K. Are sham acupuncture interventions more effective than (other) placebos? A re-analysis of data from the Cochrane review on placebo effects . Forsch Komplementrmed . 2010 ; 17 ( 5 ): 259 - 64 .
33. Meissner K , Fässler M , Rücker G , et al. Differential effectiveness of placebo treatments: a systematic review of migraine prophylaxis . JAMA Intern Med . 2013 ; 173 ( 21 ): 1941 - 51 .
34. Hróbjartsson A , Gøtzsche PC . Placebo interventions for all clinical conditions . Cochrane Database Syst Rev . 2010 ; 1 ( 3 ): CD003974 .
35. Hróbjartsson A , Gøtzsche PC . Is the placebo powerless? An analysis of clinical trials comparing placebo with no treatment . N Engl J Med . 2001 ; 344 ( 21 ): 1594 - 602 .
36. Mondloch MV , Cole DC , Frank JW . Does how you do depend on how you think you'll do? A structured review of the evidence for a relation between patients' recovery expectations and outcomes . CMAJ . 2001 ; 165 ( 2 ): 174 - 9 .
37. Di BZ , Harkness E , Ernst E , et al. Influence of context effects on health outcomes: a systematic review . Lancet . 2001 ; 357 ( 9258 ): 757 - 62 .
38. Linde K , Witt CM , Streng A , et al. The impact of patient expectations on outcomes in four randomized controlled trials of acupuncture in patients with chronic pain . Pain . 2007 ; 128 ( 3 ): 264 - 71 .
39. Sherman KJ , Cherkin DC , Ichikawa L , et al. Treatment expectations and preferences as predictors of outcome of acupuncture for chronic back pain . Spine . 2010 ; 35 ( 15 ): 1471 - 7 .
40. Wasan AD , Kong JL , Kaptchuk TJ , et al. The impact of placebo, psychopathology, and expectations on the response to acupuncture needling in patients with chronic low back pain . J Pain . 2010 ; 11 ( 6 ): 555 - 63 .
41. Zheng H , Huang W , Li J , et al. Association of pre- and post-treatment expectations with improvements after acupuncture in patients with migraine . Acupunct Med . 2015 ; 33 ( 2 ): 121 - 8 .
42. Foster NE , Thomas E , Hill JC , et al. The relationship between patient and practitioner expectations and preferences and clinical outcomes in a trial of exercise and acupuncture for knee osteoarthritis . Eur J Pain . 2010 ; 14 ( 4 ): 402 - 9 .
43. Zhao L , Chen J , Li Y , et al. The long-term effect of acupuncture for migraine prophylaxis: a randomized clinical trial . JAMA Intern Med . 2017 ; 177 ( 4 ): 508 - 15 .
44. Yun HK , Jung WY . Time course of placebo effect of acupuncture on pain: a systematic review . ISRN Pain . 2013 ; 2013 : 204108 .