Plain English Summary
Background and study aims
Regular colorectal cancer (CRC) screening is recommended for people older than 50 years old because they have a higher risk of developing this disease. However, a significant proportion of this population do not comply with this recommendation. The researchers have developed a web-based decision aid (DA) to help people to make an informed decision about undergoing CRC screening. It includes information about the disease, as well as two screening procedures: fecal occult blood test (FOBT) and colonoscopy (their characteristics, potential benefits and harms). The DA is available on the following link: http://www.pydesalud.com/toma-de-decisiones-en-cancer-colorrectal/. The aim of this study is to find out whether this DA can help people to make informed decisions about CRC screening.
Who can participate?
People between 50-69 years old who have no history of CRC or current symptoms, and who have never had been screened for CRC
What does the study involve?
Participants are randomly allocated to either individually review the DA accompanied by a researcher, or to not review the DA. The main outcome assessed is decisional conflict, that is, participants' uncertainty about undergoing CRC screening or not. The study also assesses their knowledge about CRC and the screening procedures, their intention to be screened, and the importance that they attributed to different characteristics of the screening procedures.
What are the possible benefits and risks of participating?
Regarding potential benefits, those allocated to the intervention group have access to evidence-based information about colorectal cancer screening. There are no risks of potential physical or psychological harm for participating in the trial.
Where is the study run from?
1. Primary care center of Santa Ursula (Tenerife)
2. Primary care center of Ofra (Tenerife)
When is the study starting and how long is it expected to run for?
January 2016 to March 2017
Who is funding the study?
Carlos III Health Institute (Spain)
Who is the main contact?
Mr Amado Rivero-Santana
Santa Cruz de Tenerife
Effectiveness of a decision aid for promoting colorectal cancer screening in Spain: a randomized trial
Reviewing a decision aid about colorectal cancer screening will improve participants' decisional conflict about undergoing the procedure.
Scientific and Ethics Committee of the Hospital Universitario Nuestra Señora de la Candelaria (Tenerife, Spain), January 2016, file number: 2013/21
Interventional randomised controlled trial
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
The study took place in two primary care centers: one located in an area where a public screening program was available, and other in which that program was not available at the moment of the study.
Participants were randomly allocated to the intervention (web-based decision aid) or usual care. Computerized randomization was carried out centrally by an independent researcher. Allocation was not blinded for patients and researchers.
The decision aid (DA) included information about colorectal cancer and two screening procedures: fecal occult blood test (FOBT) and colonoscopy (their characteristics, potential benefits and harms). It is available on the following link: https://www.pydesalud.com/toma-de-decisiones-en-cancer-colorrectal/
Each intervention participant reviewed the DA accompanied by a researcher in her/his primary care center. Outcome measures were assessed by questionnaires immediately after reviewing the DA.
Participants in the control group did not review the DA and just completed the questionnaires assessing the outcome measures.
Primary outcome measure
Decisional conflict, measured with the Decisional Conflict Scale (DCS) immediately after reviewing the DA in the intervention group, and at the baseline assessment in the control group
Secondary outcome measures
1. Knowledge of the disease and the screening procedures, assessed using 12 items questionnaire
2. Intention to undergo screening (yes/no)
3. Concordance between participants' values about the characteristics of the screening procedures (importance attributed in a 1-5 Likert scale) and their intention to be screened
All assessments were performed immediately after reviewing the DA in the intervention group (except for knowledge, which was also measured before the aplication of the DA), and at the baseline assessment in the control group
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Age 50-69
2. Having no CRC history or current symptoms
3. Having no family antecedents of CRC
4. Not been screened previously
Target number of participants
Total final enrolment
Participant exclusion criteria
Cognitive impairment that hinders understanding of the study aims, information provided in the DA, or filling out the questionnaires
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Primary care center of Santa Ursula (Tenerife)
Trial participating centre
Primary care center of Ofra (Tenerife)
Carlos III Health Institute (Spanish Ministry of Economy, Industry and Competitiveness)
C/ Sinesio Delgado
4 (entrada por Avda. Monforte de Lemos
Instituto de Salud Carlos III
Institute of Health Carlos III, Carlos III Health Institute, ISCIII
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
An article reporting the study results is currently under review in the journal BMC Medical Informatics and Decision Making.
IPD sharing statement
The datasets generated during and/or analysed during the current study are/will be available upon request from Lilisbeth Perestelo-Pérez (firstname.lastname@example.org). The trialists will share all of the individual participant data that underlie the results reported in this article, after deidentification (text, tables, figures and appendices). Other documents available: study protocol, statistical analysis plan, informed consent form, analytic code. The data will be available immediately following publication (no end date). The data will be available for researchers who provide a methodologically sound proposal to achieve aims in the approved proposal. Proposals should be directed to Dr Lilisbeth Perestelo-Perez (email@example.com). To gain access, data requestors will need to sign a data access agreement.
Intention to publish date
Participant level data
Available on request
Basic results (scientific)
2019 results in: https://www.ncbi.nlm.nih.gov/pubmed/30630487 (added 14/01/2019)