Vas et al. Trials 2014, 15:288
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STUDY PROTOCOL

TRIALS
Open Access

Auricular acupuncture for primary care treatmentof low back pain and posterior pelvic pain in
pregnancy: study protocol for a multicentre
randomised placebo-controlled trial
Jorge Vas1,2*, José Manuel Aranda-Regules3, Manuela Modesto1, Inmaculada Aguilar1, Mercedes Barón-Crespo4,
María Ramos-Monserrat5, Manuel Quevedo-Carrasco6 and Francisco Rivas-Ruiz2,7Abstract
Background: About 45% of all pregnant women suffer low back pain and/or pelvic girdle pain (LBPGP). This study
seeks to evaluate the effect of auricular acupuncture on LBPGP compared with placebo auricular acupuncture andwith standard obstetric care in the field of primary health care.
Methods and design: This study will be a four-parallel-arm, multicentre, randomised, placebo-controlled trial. A
total of 212 pregnant women (24 to 36 weeks’ gestation), aged at least 17 years, with LBPGP, will be randomly
assigned to the verum auricular acupuncture plus standard obstetric care group (VAAc), to the non-specific auricularacupuncture plus standard obstetric care group (NSAAc), to the non-specific placebo auricular acupuncture plus
standard obstetric care group (PAAc), or the standard obstetric care group (SOC). The VAAc, NSAAc, and PAAc
groups will receive treatment at three auricular acupuncture points (specific points for the VAAc group or non-specificones for the NSAAc and PAAc groups), once a week for 2 weeks; the SOC group will receive only standard obstetriccare during the same period. The primary outcome will be the reduction in pain intensity, according to the visual
analogue scale (iVAS), at 2 weeks after the start of treatment. The secondary outcomes will be functional status withrespect to LBPGP (according to the Roland-Morris disability questionnaire), health-related quality of life (SF12) at
2 weeks after the start of treatment, and iVAS at 12 and 48 weeks postpartum.
Discussion: This trial will implement a high-quality methodology and may provide evidence for the efficacy,
safety, and specificity of auricular acupuncture as a treatment for pregnant women with LBPGP.
Trial registration: Current Controlled Trials ISRCTN41033073 (date 20/03/2014).

Background
Musculoskeletal pain in pregnant women is often regarded
as something that is transient, physiological, and selflimiting, but low back pain (LBP) and pelvic girdle pain
(PGP) during pregnancy are associated with an increased
risk of suffering these pains in future pregnancies and of
the pain becoming chronic [1].

* Correspondence: jorgef.vas.sspa@juntadeandalucia.es
1Pain Treatment Unit. Doña Mercedes Primary Health Care Centre, Segovia s/n,
Dos Hermanas 41701, Spain
2
Carlos III Health Institute, Network of Research in Health Services in Chronic
Diseases (REDISSEC), Sinesio Delgado 4, Madrid 28029, Spain
Full list of author information is available at the end of the article

Low back pain is usually defined as occurring between
the twelfth rib and the gluteal fold. Pelvic girdle pain isexperienced between the posterior iliac crest and thegluteal fold, particularly in the vicinity of the sacroiliac
joints. The pain may radiate to the back of the thigh andmay occur in isolation or be associated with pain in thesymphysis pubis [2]. Opinions are divided as to whether
LBP and PGP should be associated or differentiated. According to some experts, they can be differentiated clinically, responding to different treatments and having
different risk factors [3]. However, studies have so far
failed to distinguish reliably between the two, and LBP isvery likely to be a subgroup of the pelvic pain associated© 2014 Vas et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, andreproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain
Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article,
unless otherwise stated.

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with pregnancy [4]. In fact, similar pathophysiologicalmechanisms – joint laxity, increased lumbar lordosis,
and muscle weakness – have been suggested to be at thecause of both conditions [5-7].
About 45% of all pregnant women suffer from LBP
and/or PGP (LBPGP) [8]. The prevalence appears to be
somewhat higher in the Nordic countries [9], and higher
still in Spain, where the prevalence at 4 weeks is estimated to be 71.3% for LBP and 64.7% for PGP [10].
LBPGP usually begins from week 18 of pregnancy, andalthough it may appear in the first quarter, the peak intensity is from weeks 24 to 36 [8].
There are three major risk factors for the developmentof LBPGP during pregnancy: strenuous work, the presence of LBP before pregnancy, and the development of
LBPGP during previous pregnancies [8]. On the other
hand, the use of contraceptives, the period of time
elapsed since the last pregnancy, maternal height andweight, smoking, and age [2] are not usually consideredrisk factors, and neither the use of epidural or spinal anaesthesia or analgesia seem to be relevant [11].
LBPGP hampers women’s everyday activities, such asgetting up, turning over in bed, sitting down, walking,dressing and undressing, lifting, and carrying small objects. It can also impede sexual relations, render subjects
unable to work [12,13], and, in general, negatively affecttheir quality of life [14].
LBPGP during pregnancy is usually diagnosed in primary care, taking into account the patient’s medical history and the results of a physical examination, which
will seek to exclude other causes of pain and to assessthe degree of disability, as well as identifying any warning signs that could indicate the presence of inflammatory, infectious, traumatic, neoplastic or degenerative
processes, that would require referral for study by otherdiagnostics [15]. It is unclear whether there exists any effective preventive intervention against LBPGP in pregnancy; prior studies on this question are conflicting[16,17] and, in any case, it appears that only pregnant
women with previous LBP might benefit from suchtreatment [17].
Various therapeutic options have been proposed for
pregnant women with LBPGP. The use of paracetamol isconsidered safe but not very effective [18]. Non-steroidal
anti-inflammatory drugs do not appear to be associatedwith foetal malformation before 12 weeks of pregnancy[19] – although before this gestational age, few womenneed such medication – but are contraindicated in thethird trimester of pregnancy, being associated with anincreased risk of premature closure of the foetal ductus
arteriosus and with oligohydramnios [20]. The association between opioid use and teratogenicity is a complicated question because the available data are contradictoryand incomplete. Although data from previous studies

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suggest that there is no significant additional risk ofcongenital anomalies, there is undoubtedly a slight increase in certain heart defects, spina bifida, and, possibly, gastroschisis [21].
Prominent among non-pharmacological interventions
are education, physical therapy, exercises, transcutaneous nerve stimulation, and acupuncture. The provisionof specific education for pregnant women and of advice
on pain-prevention strategies appears to reduce the sickleave needed by pregnant women with LBP, but not by
those with PGP [3]. A recent systematic review [22] concluded that pregnant women with LBP who performed
specifically adapted strengthening exercises in programmesof pelvic tilt exercises and water gymnastics reduced theintensity of LBP and the need for pain-related sick leave toa greater degree than was achieved by women who received only standard antenatal care. The same authors reported that specially designed pillows reduce pain morethan normal ones, but these are not available in Spain.
Studies and reviews have supported the use of acupuncture by pregnant women with LBPGP [22,23]. Thus,
it has been reported that acupuncture and stabilising exercises more effectively relieve PGP compared to standard antenatal care, and that acupuncture can provide
more relief for night-time pain than is obtained by exercise alone. In a study of pregnant women with pelvic
and back pain, acupuncture was found to be more effective than physiotherapy in reducing pain intensity[24]. Another study reported that 60% of pregnant
women who received acupuncture suffered less intense
pain, compared with 14% of those who received standard[25] antenatal care. A recent study found that acupuncture performed on women with LBPGP is more effective
when applied from week 26 than during week 20 ofpregnancy [26]. The adverse effects observed are minor
and temporary, such as bruising, pain or swelling in the
puncture site, asthenia, or nausea [25]. A recent survey
showed that over 60% of pregnant women with LBPGP
would accept some form of complementary therapy, including acupuncture [27].
The analgesia produced by acupuncture is caused bycomplex neurohormonal mechanisms involving endogenous opioids and monoamines [28], with evidenceof a sustained depression of the neurons in the spinal
dorsal horn [29]. Some of the effects of acupuncture may bepartially explained within a conventional neurophysiologicalmodel, but there remain certain empirically-supported aspects that resist conventional explanation. Furthermore, theuse of auricular acupuncture has been shown to be effective
in reducing LBP in non-pregnant women [30]. Just one
study published to date has evaluated the results of auricularacupuncture in pregnant women, and this paper reported
that the insertion of needles in the ear for a period of one
week reduces the pain and disability suffered by pregnant

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women with LBPGP [31]. This study was conducted in the
USA and in a hospital setting. However, there have beenno previous well-designed studies to evaluate the effects
of auricular acupuncture in pregnant women with LBPGP
compared with placebo auricular acupuncture, on the one
hand, and with standard obstetric care on the other, in thefield of primary health care and carried out by midwives
trained in this technique. In fact, these healthcare providers have made significant contributions to studies inthis field conducted by our research team [32].

Page 3 of 9pressure needles inserted in the ear (VAAc) together
with SOC; non-specific auricular acupuncture plus SOC(NSAAc); non-specific placebo acupuncture plus SOC(PAAc); and SOC alone (Figure 1). The results will beanalysed by statisticians blinded with regard to the allocation of patients to the different treatment groups.
Study period

February 2014 to December 2016.
Study scope and subjects

Hypothesis and study goals

Our clinical hypothesis is that acupuncture applied via
pressure needles inserted in the auricle (VAAc), associated with standard obstetric care (SOC), can reduce thepain experienced by pregnant women in the lower backand/or the posterior pelvic girdle, to a greater extent
than is achieved by SOC alone in the field of primary
health care. Additionally, the application of this technique improves patients’ functional status and healthrelated quality of life, and moderates the consumption ofdrugs used in conventional therapy, thus reducing theassociated iatrogenic effects without provoking significant iatrogenesis in itself. Secondly, VAAc applied together with SOC has specific effects, achieving a greater
reduction in the LBPGP suffered by pregnant womenthan that achieved with the application of pressure needles at non-specific pressure points (NSAAc) or withplacebo needles at non-specific points (PAAc).
The main aim of this study is to evaluate the efficacy
achieved in terms of reduction in pain intensity (0 to
100 mm visual analogue scale) at 2 weeks after starting
treatment. Our secondary aims are: i) to evaluate the efficacy in terms of improved functional status with respect
to LBPGP (according to the Roland-Morris disability
questionnaire) at two weeks after starting treatment; ii)
to evaluate the efficacy in terms of improved healthrelated quality of life (SF12) at two weeks after starting
treatment; iii) to evaluate the efficacy in terms of improvement perceived by the patient with LBPGP at two
weeks after starting treatment; iv) to evaluate the impact on temporary occupational incapacity of pregnant
women with LBPGP; v) to evaluate the efficacy in termsof reduced consumption of analgesic medication at
2 weeks after starting treatment; vi) to evaluate thepresence of LBPGP at 12 weeks postpartum; vii) to evaluate the presence of LBPGP at 48 weeks postpartum; andviii) to estimate the placebo effect and the specific andnon-specific effects of VAAc, NSAAc, and PAAc.

Methods/design
DesignMulticentre prospective randomised controlled study,
with four parallel arms, to compare acupuncture with

The study population will be composed of pregnant women(24 to 36 weeks’ gestation), aged 17 years or more, referredby their family physicians from the 21 primary care centres
participating in the study, belonging to the Andalusian
Public Health System and located in the provinces ofSeville and Málaga, diagnosed with pregnancy-related
LBPGP and who have not previously received auricularacupuncture. Women with LBPGP that began before thepregnancy, or presenting any of the ‘red flags’, which would
require examination to rule out the possible presence of
LBPGP secondary to inflammatory, infectious, traumatic,
neoplastic, or degenerative processes, together with women
receiving anticoagulant treatment or presenting dermatitisof the auricle, will be excluded from the study.
The women will be given the following information:“This study is being conducted to compare the effects ofstandard obstetric care either alone or in conjunction
with one of three types of stimulation of the ear (auricular acupuncture). One of these is similar to traditional
Chinese auricular acupuncture, while the others do notfollow these principles. One is a placebo intervention, but
all have been associated with positive outcomes in various clinical studies”. The women will also be informedof the potential risks associated with different types ofauricular acupuncture (infection, pain at the puncture
site, fainting, bruising) and that they may terminate their
participation in the study at any time without any penalty or loss of the benefits to which they are entitled. All
study participants must sign the informed consent form.
Randomisation and blinding procedures

The four study arms will be randomised centrally, at the
Costa del Sol Hospital, Research Support Unit, to achievea 1:1:1:1 allocation ratio, stratified by healthcare centre.
The health professionals taking part in the study will not
be involved in the randomisation process. Patients whomeet the inclusion criteria and give their signed informed
consent will be included in the study. After inclusion, theresearcher will contact the randomisation centre, where
the patient’s data will be recorded, and the midwife will be
informed, by telephone and by fax, of the patient’s allocation to one of the four study arms. This procedure ensuresthat randomisation will not be influenced by any of theVas et al. Trials 2014, 15:288
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Figure 1 Trial flow.

researchers involved. The patients assigned to the VAAc,
NSAAc, and PAAc groups will be blinded with respect tothe treatment allocated to them.
Treatment

A 4-hour workshop will be organised for all the midwives
participating in the study to demonstrate the implementation of the technique, the obstetric care to be provided,
and the study records to be kept. The workshop will begiven by two physicians who are specialists in acupunctureand have over 10 years’ clinical experience. At one monthafter initiating the study, a test will be applied to confirm
that the skills acquired in the workshop are retained.
Standard obstetric care (SOC)The SOC for the treatment of LBPGP in pregnancy will
include an explanation of its cause and of recommended
self-care procedures, both to prevent pain and to reduce
its intensity, together with training in specific stretching
exercises for the back and the hamstrings. In addition, thewomen participating in the study will be recommended touse paracetamol and/or visit their family doctor if the pain
intensity becomes severe.

Verum auricular acupuncture (VAAc)

Auricular pressure needles 1.5 mm long and 0.20 mm
in diameter (Pyonex Seirin, Shizuoka, Japan) (Figure 2)
will be applied to two standardised points (Shenmen
and Kidney), and at a reflex point in the region of theauricle that classically represents the lumbar or sacral
regions [33], and which will be detected by means of aprobe calibrated at 250 g of pressure (Figure 3). The
points will be located in a single ear, preferably theone on the side of the body corresponding to the location of the pain; if the pain is bilateral, the most sensitive ear will be determined by using a probe to exert apressure of 250 g. Before placing the implants, the ear
will be disinfected using chlorhexidine. The patients
will be instructed not to exert pressure on the implants
at any time.
Non-specific auricular acupuncture (NSAAc)

The needles used in the non-specific auricular acupuncturegroup will be the same as in the VAAc group, but they will
be applied at auricular points that are non-specific for
LBPGP, and which instead correspond to anatomic locations in the ankle, wrist, and shoulder (Figure 3).

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Figure 2 Auricular device used for the verum auricular acupuncture and non-specific auricular acupuncture (New Pyonex) groups andfor the placebo auricular acupuncture group.

Placebo acupuncture (PAAc)

The devices used in the placebo group will be suppliedby Seirin (Pyonex Placebo, Seirin, Shizuoka, Japan) andby 3B Scientific (Spain). They will be identical to thoseused in the VAAc group, but without the needle [34](Figure 2), and will be applied at the same non-specificpoints as for the NSAAc group.
Data sourcing and compilation

We have designed a data form on which the variables ofinterest should be entered by the researcher at eachcentre. The baseline assessment (T0), intermediate resultat one week (T1), end result at two weeks (T2), followup at 12 weeks postpartum (T3), and follow-up at
48 weeks postpartum (T4) will be performed by the midwives taking part in the study, who may also instruct thepatients on how to complete the self-administered questionnaire. The information will be electronically recorded and stored, at a single coordinating point foreach province, in a database for subsequent statisticalanalysis. Data collection will be conducted in person, attimes T0, T1, T2, and T3. Only the evaluation at T4 will
be carried out by telephone. Patient confidentiality will
be maintained by removing patient identity data fromthe database. Figure 1 summarises the flow plan for the
study.
Variables

Figure 3 Specific and non-specific auricular acupuncture points
used for the different study groups.

The primary outcome will be the reduction in pain intensity, according to the visual analogue scale (iVAS), at
2 weeks after the start of treatment. The secondary outcomes will be functional status with respect to LBPGP(according to the Roland-Morris disability questionnaire)

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and health-related quality of life (SF12) at 2 weeks after
the start of treatment, iVAS score at 12 and 48 weeks
postpartum, presence of temporary occupational incapacity, reduction in the consumption of analgesic medication at 2 weeks, and presence of pain at 12 and 48 weeks
postpartum.
The obstetric data, based on the patient’s health record, will consist of gestational age (weeks), number ofprevious pregnancies, number of children, previous caesarean sections, and whether epidural anaesthesia was
required. The personal data compiled by the midwives
participating in the study will be patient’s age (years),
weight before pregnancy and present weight (kg), height(cm), body mass index before pregnancy (calculated asweight/height2), educational level (none, primary education, secondary education, high school, university), andemployment status (employed, non-employed, type ofwork and, where appropriate, the reasons for not working). In addition, any previous pregnancy-related LBPGP
will be recorded. If the patient is temporarily unable towork, the days elapsed since this condition began will be
noted, and its follow-up at T2, T3, and T4. The data
form will also record the consumption of healthcare resources since the beginning of the LBPGP (number oftimes treated by the family doctor, number of times
emergency treatment needed at the health centre or hospital, number of visits to a medical specialist, private
doctor, company doctor, or non-conventional healthcare
professional).
In addition, data will be recorded for pain intensity, location (lower back, posterior pelvis or both, and whether
pain is radiating to the leg), onset, and frequency of pain(occasional days, nearly every day, every day). Pain intensity will be measured by a visual analogue scale(iVAS) at T0, T1, and T2, as well as at the follow-up assessments T3 and T4. There is ample evidence supporting the validity of the iVAS for pain intensity, and manystudies have corroborated its construct validity [35] andreliability [36,37]. It is a simple and fast method to assess
subjective pain intensity. The patient is asked to markon a 100-mm scale from 0 (no pain) to 100 (worst pain
imaginable) the intensity of back pain by day (iVASd)
and night (iVASn). The primary outcome, the change inpain intensity (iVAS) at 2 weeks after the start of treatment (T2), will be determined from the maximum valueof the daytime pain measurements (iVASd) or the nighttime ones (iVASn) at 2 weeks after starting treatment.
There is evidence that reductions of greater than 35 mm
on this scale are associated with an improvement perceived by the patient [38].
The women taking part in the study will be asked tocomplete the Roland-Morris disability questionnaire toassess the level of disability provoked by LBPGP at T0
and at T2. This self-administered questionnaire has been

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validated for use in Spain [39] and consists of 24 questions or statements related to incapacity caused by LBP.
Respondents are asked to award one point for eachstatement that corresponds to their current situation.
Scoring is quick and easy: the total score awarded may
range from 0 points (no incapacity caused by LBP) to 24(maximum incapacity). Changes in health-related qualityof life are valued according to the SF-12 v.2 selfadministered questionnaire. This is a generic questionnaire, derived from SF-36, which has been validated
for use in Spain [35]. Version 2 allows the researcher
to calculate the respondent’s quality of life in eight domains (physical function, physical role, pain, general
health, vitality, social function, emotional role, mental
health) and two summary components (physical andmental). A version with six items, to enable the calculation of utilities, is currently being validated. In ourstudy, this would enable a cost-effectiveness analysis tobe conducted.
The presence of anxiety and/or depression will bescreened and assessed at T0 and T2 by the Spanish version of the Goldberg Depression Inventory [40]. Thisconsists of two scales, one for anxiety and one for depression, each with nine dichotomous items (yes/no answers). A separate score is given for each scale, with one
point for each affirmative answer. In this Inventory,
which may be applied by the researcher or be selfadministered, the patient is asked whether in the last
2 weeks any of the symptoms referred to in the questions have occurred. Symptoms lasting less than 2 weeks
or of only mild impact are not counted. The questionnaire can be applied even by non-medical staff, and no
standardisation is required. Each of the subscales is divided into four initial screening items to determine
whether a mental disorder is likely to be present, and asecond group of five items will be asked only if positive responses are given to the screening questions (scores of ≥2
on the anxiety subscale and ≥1 on the depression subscale). Cut-off points are ≥4 for the anxiety scale and ≥2
for the depression scale. There is a clear improvement in
the sensitivity of this Inventory with increasing severity ofthe psychopathology, with higher scores being obtained,
which can provide a separate dimensional measure of theseverity of each disorder. Raising the cut-off points to ≥5and ≥3 improves the specificity and the discriminatory
power of the scales, but slightly reduces their sensitivity(specificity 93%, sensitivity 74%).
At the end of treatment (T2), the patient’s perceived
improvement will also be assessed. A 7-point Likert
scale has been recommended to assess the perceived improvement of a patient with non-specific LBP [41], butopinions differ regarding the categories to be used; we
opted for the suggestion made by Hudak and Wright[42]: How satisfied are you with the results of your

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recent treatment for low back pain and/or posterior pelvic pain? 1 = very satisfied, 2 = very satisfied, 3 = somewhat
satisfied, 4 = indifferent (about equally satisfied and dissatisfied), 5 = somewhat dissatisfied, 6 = very dissatisfied, and7 = extremely dissatisfied.
We will also evaluate the consumption of analgesic
medication, whether or not prescribed by the patient’s
doctor, both at the time of randomisation (T0) and at
final assessment (T2), according to a 4-point Likert scaleof 0–3: (0) = none, (1) = less than the usual dose, (2) =usual daily dose, and (3) = greater than the usual dose.
We will also record the names of the medications taken
and the daily dose in each case.
The Treatment Credibility Scale [43] will be used toevaluate patients’ expectations and the credibility of thetreatments provided in the study. The original Borkovec
and Nau scale [44] with four items will be applied, assessing the following questions on a continuous VAS of 0 to
10 (0 to 10, from totally disagree to totally agree): (1) =Are you confident that this treatment can alleviate yourpain? (2) = Does it seem a logical treatment? (3) = Would
you recommend this treatment to a friend or family member who was suffering the same problem? (4) = Do you
think this treatment would be an option for treating otherproblems? Questions 1 and 2 will be assessed after the
first treatment session, and questions 3 and 4, after
2 weeks.
After the treatment has concluded, the blinding of thepatients’ allocation to one of the two auricular acupuncture groups (real or placebo) will be verified by the following dichotomous question: Do you think you wereassigned to the real auricular acupuncture group or to
the placebo group?
During the study, side effects and possible adverse reactions resulting from the treatment will be recorded.

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Taking Wang et al. [31] as a reference, for the primary
purpose of the study, namely to compare the change inpain intensity, assessed on an iVAS, between the baseline
assessment and the value at 2 weeks after the intervention, a difference of over 20 mm between the VAAc
group and the SOC group will be considered statisticallysignificant. For a known standard deviation of 25 mm
for each group, a type I (alpha) error of 0.01 and a typeII (beta) error of 0.10, 47 patients per group will be required. Including the patients for the PAAc and NSAAc
arms, and with an estimated 10% loss to intervention
follow-up, a total of 212 patients (53 per group) willneed to be assessed.

demographic information, prognostic variables, and theevaluation of credibility, using measures of central tendency and dispersion for the quantitative variables andfrequency distributions for the qualitative ones.
To determine the primary study outcome (change inpain intensity at 2 weeks) and secondary outcomes(change at 2 weeks in functional status with respect topain, quality of life, and improvement perceived by thepatient), a crude analysis will be performed to compare
the mean differences between baseline values and at
2 weeks, for the VAAc group and the SOC group, using
the Student t-test for independent samples or the MannWhitney U test if the samples do not present a normal
distribution (determined by the Shapiro-Wilk test). Subsequently, simple and multivariate linear regression analyses will be performed, using the same outcome variables,
to adjust for unbalanced independent variables, including
the treatment group in the first pass, and determining regression coefficients with the corresponding 95% confidence intervals and the coefficient of determination. The
main analysis will be by intention-to-treat, but a perprotocol analysis will also be performed.
To determine the secondary outcomes of presence oftemporary occupational incapacity, reduction in the consumption of analgesic medication at 2 weeks, and presence of pain at 12 and 48 weeks postpartum, the VAAc
and SOC groups will be compared, using the χ2 test with
continuity correction or Fisher’s exact test when the expected values are below 5. Then, simple and multivariate
logistic regression models will be obtained, with thesame outcome variables, to adjust for unbalanced independent variables, including the treatment group in thefirst pass, and the relative risk will be determined, with
95% confidence intervals.
Both the quantitative outcome variables (mean differences) and the qualitative ones (difference in proportions)will be expressed with the respective 95% confidence intervals and intention-to-treat analysis criteria will be used
(last known value for losses-to-study for the quantitative
outcome variables, and penalisation of results in the experimental treatment for the qualitative variables). To assess the specificity of the effect of auricular acupuncture,previous analyses comparing the VAAc treatment groupversus PAAc and NSAAc will be repeated. In each test,
the bilateral statistical significance limit of P <0.01 will
established. An intermediate analysis will be performed
when complete tracking is concluded for half of the sample population, setting the level of bilateral statistical significance at P <0.005, this being a necessary penalisation
to minimise type I errors.

Statistical analysis

Ethical issues

A descriptive analysis will be performed to assess thecomparability of the four groups with regard to baseline

The ethical validity of this study has been examined by the
Regional Clinical Trials Committee. It was subsequently

Sample size

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approved by the Research Ethics Committee (Comité deÉtica de la Investigación Área Sanitaria Sevilla Sur,20130429). The project has received funding from a public
national call for proposals, awarded on a competitive
basis. The study complies with the Declaration of Helsinki
and subsequent updates (to the 2008 revision) and takes
into account the principles set out in the Council ofEurope Convention on Human Rights and Biomedicine,
as well as the requirements established by Spanish legislation regarding biomedical research, the protection of personal data, and bioethics. During the course of the study,
audits will be performed as required by the abovementioned Research Ethics Committee and by the hospital’s Quality Commission, independently of any external
audits (source of research funding) that may be deemednecessary. The forms, case report data, and computer data
files will be identified with codes, not the names of the patients, in order to protect personal data. Statistical analysis
will be performed by third parties who will be unaware of
the source data (blinded analysis).

Discussion
When auricular acupuncture is practiced according to
the principles of Traditional Chinese Medicine, it is anindividualised treatment. In this study we have designed
a semi-standardised treatment protocol that approximates standard clinical practice, which is sufficiently
flexible and straightforward so that it can be performedby midwives without prior training, and which enables
reproducibility.
As this experimental study is designed to be appliedby medical personnel whose training is limited to an intensive 4-hour course in the technique, obviously theauricular acupuncture treatment cannot be performed toits full extent. For this reason, we have limited the number of points where acupuncture needles will be applied,
and therefore the therapeutic effect obtained may be lessthan that otherwise to be expected. This limitation willproduce an effect contrary to the study hypothesis.
Moreover, the patients assigned to the PAAc and
NSAAc groups, due to the healthcare provided and theeffects of dermatological stimulation, however minimal,
may achieve some positive results. This effect, too, is
contrary to the study hypothesis, but to a certain extent
will reflect the non-specific effect of the intervention.
A double-blind study cannot be carried out because
the therapist must know which treatment is being applied. We have attempted to minimise the consequencesof this situation by ensuring that the professional who
provides the treatment does not intervene in the assessment of the outcome. Furthermore, the blinding of theevaluators and the patients is designed to be highly effective. In addition, a question will be included to determine the patients’ perceptions regarding the type ofPage 8 of 9auricular acupuncture received. Since the main outcome
variable and many of the secondary ones will be recorded by means of a self-administered questionnaire no
added bias will be caused by the intervention of the midwife in this area.
The patients will be asked not to receive any alternative treatment. Nevertheless, although the women in the
study population will be asked to confirm this, we cannot be absolutely certain of compliance. Further, an important limitation may arise from the patients’ lack ofadherence to the prescribed treatment, as for various
reasons they may fail to attend one or more treatment
sessions. The main analysis will be by intention-to-treat,but a per protocol analysis will also be performed. The
sample size was calculated on the assumption of a 10%
drop-out rate, but it will be necessary to ensure there
are no differential losses between the three treatment
arms.

Trial status
Currently in the patient-recruitment phase.
Abbreviations
iVAS: Pain intensity, according to the visual analogue scale; iVASd: Pain
intensity by day, according to the visual analogue scale; iVASn: Pain intensity
by night, according to the visual analogue scale; LBP: Low back pain;
LBPGP: Low back pain and/or pelvic girdle pain; NSAAc: Non-specificauricular acupuncture; PAAc: Non-specific placebo auricular acupuncture;
PGP: Pelvic girdle pain; SF12: 12-Item short form health related quality of life
survey; SOC: Standard obstetric care; VAAc: Verum auricular acupuncture.
Competing interests
The authors declare that they have no competing interests.
Authors’ contributions
JV conceived the study, designed the study protocol, sought funding andethical approval, and wrote the manuscript. JMAR, MM, IA, MBC, and MQC
made a substantial contribution to designing the individualised acupuncture
treatment protocol, MRM made a critical review of the protocol. FR is
responsible for the statistical analyses. All authors have critically reviewed
and approved the final version of the manuscript. The corresponding author
has final responsibility for the decision to submit for publication.
Acknowledgements
This study has been awarded a grant (No. PI13/00010) in a competitive
application process of the programme for the promotion of biomedical
research and health sciences for the performance of clinical research projectsof a non-commercial nature, from the Spanish Ministry of Health and Consumer
Affairs (Carlos III Health Institute).
Author details
1
Pain Treatment Unit. Doña Mercedes Primary Health Care Centre, Segovia s/n,
Dos Hermanas 41701, Spain. 2Carlos III Health Institute, Network of Research in
Health Services in Chronic Diseases (REDISSEC), Sinesio Delgado 4, Madrid
28029, Spain. 3San Andrés Torcal Primary Health Care Centre, José Palanca s/n,Málaga 29003, Spain. 4El Lugar Primary Health Care Centre, Jesús Nazareno s/n,
Chiclana 11130, Spain. 5Mallorca Cancer Registry. Balearic Islands Public Health
Department, Hospital Psiquiàtric, Camí de Jesús 40, Palma 07010, Spain. 6Vélez
Sur Primary Health Care Centre, Fernando Vivar s/n, Vélez-Málaga 29700, Spain.
7
Support Research Unit, Costa del Sol Hospital, Autovia A-7, Km 187, Marbella
29603, Spain.
Received: 13 May 2014 Accepted: 1 July 2014
Published: 16 July 2014

Vas et al. Trials 2014, 15:288
http://www.trialsjournal.com/content/15/1/288

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doi:10.1186/1745-6215-15-288
Cite this article as: Vas et al.: Auricular acupuncture for primary caretreatment of low back pain and posterior pelvic pain in pregnancy: study
protocol for a multicentre randomised placebo-controlled trial. Trials
2014 15:288.