The effect of information about the benefits and harms of mammography on women’s decision-making: study protocol for a randomized controlled trial
Carles et al. Trials
The effect of information about the benefits and harms of mammography on women's decision-making: study protocol for a randomized controlled trial
Misericòrdia Carles 0 1 11 12
Montserrat Martínez-Alonso 0 2
Anna Pons 16
Maria José Pérez-Lacasta 1 12
Lilisbeth Perestelo-Pérez 14 15 18
Maria Sala 13 17 18
Carmen Vidal 9
Montse Garcia 9
Ana Toledo-Chávarri 10 18
Núria Codern 7 8
Maria Feijoo-Cid 5
Anabel Romero 13 17 18
Roger Pla 1 3 6
Jorge Soler-González 4 16
Xavier Castells 13 17 18
Montserrat Rué 1 2 18
on behalf of the InforMa Group
0 Equal contributors
1 Research Group on Economic Evaluation and Health (GRAES) , Reus , Spain
2 Department of Basic Medical Sciences, University of Lleida-IRBLLEIDA , Lleida , Spain
3 Medical School, University Rovira i Virgili , Reus , Spain
4 Department of Medicine, University of Lleida , Lleida , Spain
5 Department of Nursing, Faculty of Medicine, Universitat Autònoma de Barcelona , Bellaterra , Spain
6 Catalan Health Service , Tarragona Region, Tarragona , Spain
7 ÀreaQ, Evaluation and Qualitative Research , Barcelona , Spain
8 Nursing and Occupational Therapy School (EUIT) , Terrassa , Universitat Autònoma de Barcelona , Barcelona , Spain
9 Cancer Prevention and Control Program, Catalan Institute of Oncology-IDIBELL, L'Hospitalet de Llobregat , Spain
10 Canary Islands Foundation of Health Research (FUNCANIS) , Tenerife , Spain
11 Research Centre on Industrial and Public Economics, (CREIP) , Reus , Spain
12 Department of Economics, University Rovira i Virgili , Reus , Spain
13 IMIM (Hospital del Mar Medical Research Institute) , Barcelona , Spain
14 Center for Biomedical Research of the Canary Islands (CIBICAN) , Tenerife , Spain
15 Evaluation Unit of the Canary Islands Health Service (SESCS) , Tenerife , Spain
16 Lleida Biomedical Research Institute (IRBLLEIDA) , Lleida , Spain
17 Epidemiology and Evaluation Department, Hospital del Mar , Barcelona , Spain
18 Health Services Research on Chronic Patients Network (REDISSEC) , Madrid , Spain
Background: The decision to participate or not in breast cancer screening is complex due to the trade-off between the expected benefit of breast cancer mortality reduction and the major harm of overdiagnosis. It seems ethically necessary to inform women so that they can actively participate in decision-making and make an informed choice based on their values and preferences. The objective of this study is to assess the effects of receiving information about the benefits and harms of screening on decision-making, in women approaching the age of invitation to mammography screening. Methods: A two-stage, randomized controlled trial (RCT). In the first stage, 40 Basic Health Areas (BHAs) will be selected and randomized to intervention or control. In the second stage, women within each BHA will be randomly selected (n = 400). Four breast cancer screening programs (BCSPs) of the Spanish public health system, three in Catalonia and one in the Canary Islands will participate in the study. Women in the intervention arm will receive a leaflet with detailed information on the benefits and harms of screening using mammography. Women in the control arm will receive a standard leaflet that does not mention harms and recommends accepting the invitation to participate in the biennial examinations of the BCSP. The primary outcome is informed choice, a dichotomous variable that combines knowledge, attitudes, and intentions. Secondary outcomes include decisional conflict; confidence in the decision made; anxiety about screening participation; worry about breast cancer; anticipated regret; time perspective; perceived importance of benefits/harms of screening; perceived risk of breast cancer; and leaflet acceptability. Primary and secondary outcomes are assessed 2-3 weeks after the intervention. Discussion: This is the first RCT that assesses the effect of informing about the benefits and harms of breast cancer screening in Spain in women facing the decision to be screened using mammography. It aims to assess the impact of information on several decisional outcomes and to contribute to paving the road towards shared decision-making in breast cancer screening in our country. (Continued on next page)
(Continued from previous page)
Trial registration: ClinicalTrials.gov registry, ID: NCT03046004. Retrospectively registered on 4 February 2017. Trial
name: InforMa study.
Background and rationale
The objective of breast cancer screening is to find cancer
at an early stage when it may be easier to treat. Evidence
shows that screening reduces breast cancer mortality by
around 20% [
]. However, screening can produce harms
or undesired effects such as false-negative and
falsepositive results, and the overdiagnosis of tumors that
would not cause health problems during the woman’s
lifetime in the absence of screening [
The decision to participate or not in breast cancer
screening is complex. On the one hand, there is a
tradeoff between the expected benefit of breast cancer
mortality reduction and the major harm of
overdiagnosis. On the other hand, there is uncertainty on the
magnitude of overdiagnosis, with an estimated frequency
of 11% of breast cancer cases from a population
perspective, and about 19% from the perspective of a woman
invited to screening [
]. It seems ethically necessary to
inform women so that they can actively participate in
decision-making and make an informed choice based on
their values and preferences.
The need to develop and test decision aids (DAs) for
breast cancer screening is clear. DAs are tools that help
people become involved in decision-making by making
explicit the decision that needs to be made, providing
information about the options and outcomes, and by
clarifying personal values [
]. Information on cancer screening
is often biased, incomplete and persuasive [
health professionals think that informing women about
screening harms may deter them from being screened,
with negative consequences for them . A systematic
review by Hoffmann and Del Mar shows that women
overestimate the benefits and underestimate the harms of
]. In addition, women overestimate the risk of
breast cancer and most of them have not been informed
of the adverse effects of screening. This explains why the
majority of women believe very strongly that screening is
almost always a good idea and that finding cancer early
saves lives [
We performed a systematic review of the effects of DAs
about breast cancer screening in women aged 50 years or
younger, facing the decision to be screened [
]. Only four
studies were included in the review [
], three of them
published in 2015, which can be explained by the recent
development of DAs for breast cancer screening.
Moreover, the DAs were designed in Australia, the USA, and
Germany, limiting the generalizability of the results to our
country, Spain. The meta-analysis of these studies showed
that DAs improve knowledge and promote informed
decisions, but divergent results on decisional conflict and
confidence in the decision were observed. We concluded
that more research is needed for the improvement of DAs
and for assessing its impact on women’s decisions.
Prior to the start of the randomized controlled trial
(RCT) we performed a qualitative study with focus
groups of women and health professionals with the aim
of testing and improving an informative leaflet for breast
cancer screening [
]. The effect of this leaflet in women
facing the decision to participate in breast cancer
screening is being assessed in the on-going study
described by the present protocol.
The objective of this study is to assess the effect of
receiving information about the benefits and harms of breast
cancer screening on informed choice and other
decisionmaking outcomes in women approaching the age of
invitation to mammography screening.
The study is designed as a two-stage RCT. In order to
reduce intragroup contamination, in the first stage, 40
Basic Health Areas (BHAs) from two regions of Spain
are selected and randomized to intervention or control.
BHAs are the elementary territorial units of the health
care system where primary health care and health
promotion actions are provided to the population. In the
second stage, women within each BHA will be randomly
selected. To the best of our knowledge this is the first
multicenter RCT on the effect of providing balanced
information for breast cancer screening in Spain prior to
being invited to screening using mammography. The
primary outcome is informed choice, a dichotomous
outcome that combines knowledge with consistent
attitudes and intentions [
A pilot study was carried out with 30 women to test
the recruitment procedures and the data collection
process. Questionnaires were also checked for
understanding and acceptability.
This study protocol follows the Standard Protocol Items:
Recommendations for Interventional Trials (SPIRIT)
guidelines (see Additional file 1).
Participants, interventions, and outcomes
In Spain the National Health System provides universal
and free health coverage, including early detection of
breast cancer. All women resident in Spain aged 50 to
69 years are actively invited to participate in the
population-based screening program by a written letter
every 2 years. Breast cancer screening follows the
European Guidelines for Quality Assurance in
Mammographic Screening [
] and its results meet the required
standards. The invitation letter contains basic information
about the program, mostly about its benefits.
Four breast cancer screening programs (BCSPs) of the
Spanish public health system, three in Catalonia and one
in the Canary Islands will participate in the study. All
the BHAs of the participating BCSPs will be stratified by
socioeconomic level. For two of the BCSPs in Catalonia
the strata will be quintiles of a deprivation index. For the
third BCSP in Catalonia we performed a principal
components analysis that indicated that immigration rate
and percentage of population older than 64 years were
the variables that better separated the BHAs. Based on
these two dichotomized variables four strata will be
obtained. For the Canary Islands, the BHA strata will be
obtained considering the immigrant rate, the proximity
to health care services, and a rural/urban categorical
Five blocks of two BHAs (one intervention and one
control) will be randomly selected from the
socioeconomic strata in each BCSP, for a total of 40 BHAs.
Random samples of 30 to 50 women will be obtained
within each BHA. The size of the selected samples will
depend on the number of eligible women in each BHA
and on the observed participation in the pilot study.
Women potentially eligible within the selected BHAs
range from 15 to more than 300. If a selected BHA has
less than 30 potentially eligible women, all the
potentially eligible women of the nearest BHA within the
same socioeconomic strata will be added before selection
of the random sample. The target sample size is 10
women per BHA, a total of 400 women, 200 in the
intervention and 200 in the control group.
Inclusion criteria are being a woman aged 49–50 years
who, in 2–4 months, will be invited to participate in the
screening program for the first time. The participant
BCSPs are managed by Hospital del Mar in Barcelona,
the Cancer Prevention and Control Program of the
Catalan Institute of Oncology, the Canary Islands Health
Service, and the Lleida Health Region.
Women will be excluded if they have a personal
history of breast cancer; have difficulty speaking Spanish
or Catalan; and have cognitive impairment that prevents
them from understanding or completing the materials
based on the interviewer’s judgment. Women with a low
literacy level will not be excluded.
Women in the intervention arm will receive a leaflet
with detailed information on the benefits (breast cancer
mortality reduction, less intensive treatments) and harms
(false-positive results and overdiagnosis) of screening.
Women in the control arm will receive a standard leaflet
that does not mention harms and recommends accepting
the invitation to participate in the biennial examinations
of the BCSP. The intervention leaflet is included in
Additional file 2.
The intervention leaflet was drafted from existing
published leaflets and its estimates of the effects of screening
are drawn from published systematic reviews, clinical
trials or observational studies. The leaflet was evaluated
using a qualitative design with focus groups of women
and health professionals [
]. We analyzed women’s
perception of the leaflet information on benefits and
harms of screening, and also health care professionals’
perceptions of the convenience of providing it. The
leaflet was rewritten accordingly, and assessed for
acceptability in a pilot study.
With the aim of comparability, the outcome measures
follow the Hersch et al. study protocol [
] very closely
and will be collected using two questionnaires
(preintervention (Q1) and post-intervention (Q2)) which are
included in Additional files 3 and 4, respectively. Most
of the outcome measures will be obtained through
validated scales that have shown suitability in previous
studies. We have translated them to Catalan and Spanish.
The post-intervention measures will be assessed at 2–4
weeks after the intervention.
The primary outcome is informed choice. It is a
dichotomous outcome defined as adequate knowledge and
intentions consistent with attitudes (positive or negative)
]. It is included in Sections 2, 3, and 4 of the
post-intervention survey. The proportion of women with
an informed choice will be compared between the two
study groups. The three component variables of
informed choice: knowledge, attitudes, and intentions, will
be analyzed and reported separately.
Conceptual and numerical knowledge will be assessed
following the Hersch et al. study [
] adapted to the
mortality, incidence, and outcomes of screening data of
our setting. The threshold to define adequate knowledge
for informed choice is to score at least 50% of the
available marks, including at least one numerical mark, on
all the three screening outcome subscales that refer to
mortality reduction, overdiagnosis, and false positives.
Screening attitudes will be measured using five items
adapted from Dormandy et al. [
]. Each item ranges
from strongly negative to strongly positive [
scores can range from 5 to 25. A positive attitude is
defined as a total score ≥ 20.
Intentions to participate in screening will be measured
with one question with five responses that will be
dichotomized as categories 1–2 (responses definitely will
and will) indicating “intending” to screen and categories
3–5 (responses unsure, will not, and definitely will not),
indicating “not intending” to screen [
Secondary outcomes include decisional conflict;
confidence in the decision made; anxiety about screening
participation; worry about breast cancer; anticipated
regret; time perspective; perceived importance of benefits/
harms of screening; perceived risk of breast cancer; and
leaflet acceptability. Secondary outcomes are included in
Sections 5 to 7 of the post-intervention questionnaire. In
addition, screening participation and reasons for
nonparticipation will be assessed.
Decisional process (conflict and confidence)
Decision conflict will be assessed using the Decisional
Conflict Scale (10-item low-literacy version) by
]. The items’ responses are yes, no, and not
sure. Confidence in the decision made will be measured
with three questions with five response options ranging
from very little to very much.
Anxiety about screening participation
Anxiety will be measured with the six-item short form
of the Spielberger State-Trait Anxiety Inventory [
with four responses from not at all to a lot.
Worry about breast cancer
A single item will measure the women’s level of worry
about developing breast cancer, using four verbal
response categories ranging from not worried at all to
very worried [
This will be measured with two items from a validated
scale. The first measures inaction regret and the second
action regret. Both items have five response categories
ranging from strongly agree to strongly disagree [
This will be assessed using the short form of the
Consideration of Future Consequences Scale [
]. It includes
four-items with five response categories ranging from
strongly agree to strongly disagree.
Perceived importance of screening benefits/harms
This will be assessed with three questions on the
importance of avoiding a breast cancer death, being diagnosed
and treated for a cancer that is not harmful, and having
a false-positive result, when deciding screening
]. The response options range from very
important to not at all important.
Perceived personal risk of breast cancer
This will be measured with two questions, one about the
perception of personal risk for developing breast cancer
during lifetime, in absolute terms (with four response
categories ranging from no chance to high chance) [
] and relative to an average woman of the same age
(using five response categories ranging from much lower
to much higher) [
Perceived personal chances of screening benefits/harms
This will be measured with three questions on the
perceived personal chance of experiencing specific
outcomes if they participate in screening, compared with an
average screened woman [
]. The response
categories range from much lower to much higher.
Both leaflets, intervention and control, will be assessed
with five items, extracted from the nine items of Hersch
et al. [
]: (1) Read the leaflet all the way through? (yes/no),
(2) Length of the leaflet (responses range from much too
short to much too long), (3) Balance of the leaflet (responses
range from clearly slanted towards screening to clearly
slanted away from screening), (4) The leaflet was clear and
easy to understand (responses range from strongly agree to
strongly disagree), and (5) Found the leaflet helpful in
making decision (responses range from strongly agree to
After women have been invited to undergo the screening
mammogram, participation and reasons for
nonparticipation will be obtained through the corresponding
BCSPs. Reasons for non-participation will be categorized
as: already had a mammogram elsewhere; did not receive
invitation; on holiday; ill/hospitalized; postponed to next
round; forgot appointment; already having treatment for
cancer; not interested; screening does not work;
screening has adverse effects; other.
The study time period is 1 July 2016 to 31 August 2017.
Allocation of the BHAs to the intervention or control
groups was established at the beginning of the study.
The participant timeline is detailed in Fig. 1.
The primary analysis will compare the proportion of
women who make an informed choice in the two groups
using a chi-square test and the 95% confidence interval
of the difference of proportions. We have considered
clinically relevant an absolute difference of 20%. Assuming
that the proportion of one group is 50% (conservative
scenario) and estimating an intraclass correlation coefficient
equal to 0.1 (cluster sampling), in order to achieve an 80%
power to detect a group difference of 20%, with a
twosided significance level of 5%, a sample size of 200 women
per group is required. The 400 women will be distributed
in 100 per each BCSP. This sample size is sufficient to
detect a difference of 20% in the secondary outcome
intention to participate and a mean difference of 0.35
standard deviations in the knowledge and attitudes scales.
Assuming that 60% of women invited to participate will
accept and 20% will be lost to follow-up, a minimum of
840 women, 210 per BCSP, will be invited.
All selected women will receive a mailed invitation letter
with a summary of the study objectives. In an interval of
2 weeks, a phone call will be made where trained
interviewers briefly introduce and describe the study and
determine eligibility (assessment of the
inclusion/exclusion criteria). The interviewers will inform the women
that participation consists of answering two
questionnaires, either via web or by phone with a prior mailing
of the questionnaires. Consent will be obtained orally
and women will be told they can leave the study at any
Information technologies use and
BC risk factors
BC screening experience
General BC screening
knowledge, attitudes and
Leaflet utilization and
Informed choice, screening
knowledge, attitudes and
Decision process and confidence
Anticipated regret and time
Perceived importance and
personal chances of screening
benefits and harms
Perceived personal risk of BC
time, with no effect on being invited to the screening
Assignment of interventions
Sequence generation, allocation concealment and
In order to reduce the intragroup contamination, the
first stage of sampling will randomly assign 10 BHAs of
each screening program to the intervention and control
groups. In total, 20 BHAs will be assigned to each study
group using computer-generated blocks of size 2. In the
second stage, the public system health registries will be
used to select the target population using a
computergenerated sequence of random numbers.
The random allocation sequence will be generated by
a statistician with no contact with the participants (MR).
The interviewers responsible for the recruitment of
participants will not be aware of the women’s allocation.
It will not be possible to blind the intervention to the
interviewers and participants. The interviewers will be
independent of the research team and, for women who
choose answering by phone, the interviews will follow a
structured outline and will be continuously monitored
by the study team. Statistical analyses and drawing of
conclusions from these will be conducted on an
intentionto-treat basis and according to the study protocol. The
data analysts will be blinded to intervention status.
Data collection, management, and analysis
Data collection methods
After acceptance, the first questionnaire (Q1) will be
sent to the study participants. Q1 is included in the
Additional file 3 and has the following sections: (1)
sociodemographic data (including education level and
work situation), (2) previous screening experience
(opportunistic screening use, if applicable, periodicity of
mammographic examinations, previous breast lesions,
previous diagnostic tests for breast lesions), (3) risk
factors of breast cancer (age at menarche, reproductive
history, age at menopause, if applicable, use of hormone
replacement therapy, use of oral contraceptive drugs,
and family history of breast cancer), (4) use of
information technologies, (5) general screening knowledge, (6)
screening attitudes, (7) screening intentions, and (8)
medical literacy according to the short version of the
European Health Literacy Survey Questionnaire
The post-intervention questionnaire (Q2) has the
following sections: (1) leaflet acceptability, (2) screening
knowledge, (3) screening attitudes, (4) screening
intentions, (5) decision process, (6) decisional confidence, (7)
anxiety, (8) anticipated regret, (9) time perspective, (10)
perceived importance of benefits and harms, (11)
perceived personal chances of screening benefits and harms,
and (12) perceived personal risk of breast cancer.
Participation in the screening program will be assessed at
3 months after completing accrual.
All the data will be entered and recorded with the open
source LimeSurvey [
]. Range checks and error alerts
will be used to prevent invalid data. R software will be
used for data analysis [
Primary and secondary outcomes in the two study groups
will be compared using the chi-square test for categorical
variables and the Student’s t and Mann-Whitney U tests
for quantitative variables. These standard tests will be
adjusted for the inflation in variance that can be attributed
to clustering of responses within BHAs [
mixed-effects models [
] will be used to assess the effect
of the intervention on the outcomes accounting for
women’s characteristics and the intracluster correlation
induced by the BHAs. If missing values reduce the sample
size by more than 10%, multiple imputation and sensitivity
analysis will be used. No subgroup analyses will be
This is the first RCT trial assessing the effect of
informing about the benefits and harms of breast cancer
screening in Spain in women facing the decision to be
screened using mammography. The leaflet used in the
intervention arm is based on current evidence from
systematic reviews and has been adapted to local data
on incidence and mortality.
In the qualitative study designed for developing the
leaflet of the intervention group, women showed a lack
of knowledge of the existence of overdiagnosis and
surprise that they had not been informed of this issue
]. The current study aims to assess the impact of
informing Spanish women on several decisional
outcomes and contribute to paving the road towards shared
decision-making in breast cancer screening in our
With the aim of comparability, the outcome measures
follow very closely the Hersch et al. study protocol [
Most of the outcome measures are obtained through
validated scales that have been used in previous studies.
One of the study limitations is that the intervention
may not reach women with low literacy or who are
recent immigrants. Moreover, the intervention leaflet
may not meet the needs of some population groups,
such as people with cognitive impairment, to understand
or complete the materials or persons who do not speak
Spanish or Catalan.
As of 30 June 2017, we have enrolled 335 of our target
400 participants in the study.
Additional file 1: SPIRIT Checklist. Checklist of the Standard Protocol
Items: Recommendations for Interventional Trials (SPIRIT) guidelines.
(PDF 99 kb)
Additional file 2: Study leaflet. Leaflet with detailed information on the
benefits and harms of screening with mammography, used in the
intervention arm of the study. (PDF 791 kb)
Additional file 3: Pre-intervention questionnaire (Q1). Baseline
characteristics of participants. (PDF 253 kb)
Additional file 4: Post-intervention questionnaire (Q2). Study outcomes.
(PDF 298 kb)
BCSP: Breast cancer screening program; BHA: Basic Health Area; DA: Decision
aids; HLS-EU-Q16: European Health Literacy Survey Questionnaire-short
version; ICMJE: International Committee of Medical Journal Editors; ID: Identifier;
Q1: Pre-intervention questionnaire; Q2: Post-intervention questionnaire;
RCT: Randomized controlled trial
We are indebted to Francesc Macià, Montse Llorens, Mariola de la Vega and
Juan Manuel González for collaborating in the selection of BHAs and
Members of the InforMa Study Group (alphabetical order): ÀreaQ, Evaluation and
Qualitative Research, Barcelona: Àngels Cardona and Núria Codern; Canary Islands
Health Service (SESCS): Lilisbeth Perestelo-Pérez and Ana Toledo-Chávarri;
Universitat Auntònoma de Barcelona (UAB): Maria Feijoo; Cancer Prevention and
Control Program, Catalan Institute of Oncology, L’Hospitalet de Llobregat:
Montse García and Carmen Vidal; IRBLLEIDA-Universitat de Lleida: Sara Buil, Clara
Viñals, Laia Viñals, Montserrat Martínez-Alonso, Marta Ortega, Sandra Pla, Anna
Pons-Rodríguez, Montserrat Rué, and Jorge Soler; URV (University Rovira i Virgili),
Reus: Misericòrdia Carles, Maria José Pérez, and Roger Pla; IMIM, Hospital del
Mar Medical Research Institute, Barcelona: Andrea Burón, Xavier Castells, Anabel
Romero, and Maria Sala.
This work is supported by the research grant “Women participation in
decisions and strategies on early detection of breast cancer” (PI14/00113)
from the Instituto de Salud Carlos III and cofunded by Fondo Europeo de
Desarrollo Regional (FEDER) “Una manera de hacer Europa.” Anna Pons
received a grant for PhD students from the Lleida Biomedical Research
Institute (IRBLLEIDA). The funders will not participate in the study design;
collection, management, analysis, and interpretation of data; writing of the
report; and the decision to submit the report for publication.
Availability of data and materials
Data sharing and dissemination
All the data and code (in R) will be deposited online for reproducibility under a
creative commons license (e.g., figshare with github integration or similar).
The results of the trial will be presented at national and international conferences
relevant to the subject field and will be submitted to international peer-reviewed
journals. The trial will be reported in accordance with the Consolidated Standards
of Reporting Trials (CONSORT) Statement [
MR, MC, MMA, and MJP designed the study. LP, MS, MG, CV, and AR coordinated
the study sample selection and participated actively in the questionnaires design.
AT, NC, and MF coordinated and actively participated in the elaboration of the
leaflet for the intervention group. RP, JS, and XC provided feedback on the
quantification and presentation of the benefits and harms of breast cancer
screening in the intervention leaflet. All authors contributed to discussion and
revisions to the study design. MR, MMA, and AP drafted the manuscript. All
authors read and approved the final manuscript.
Ethics approval and consent to participate
The study was approved by the Ethics Committees of the hospitals
Universitari Arnau de Vilanova, in Lleida and Parc de Salut Mar in Barcelona
(approval numbers 19/2014 and 2014/5998/I, respectively), and by the
Scientific and Ethics Committee of the University Hospital Nuestra Señora de
la Candelaria, in Tenerife (Canary Islands, Spain). The study is performed in
accordance with Good Clinical Practice and the Declaration of Helsinki.
Informed consent will be obtained by phone after verifying that the
inclusion criteria are met and it will be documented by the interviewer.
All participants will be assigned an ID number and all the questionnaires and
datasets will be anonymized. Only the study team will have access to the
document that links study ID with participant names. All the study files are
electronic and will be stored on secure servers on password-protected
Consent for publication
All authors have completed the International Committee of Medical Journal
Editors (ICMJE) uniform disclosure form at www.icmje.org/coi_disclosure.pdf
and declare: funding from the Spanish Ministry of Health and the Biomedical
Research Institute of Lleida (IRBLLEIDA) as described below; no financial
relationships with any organizations that might have an interest in the
submitted work in the previous 3 years; no other relationships or activities
that could appear to have influenced the submitted work.
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