Subjects
The study included 42 fifth-semester students from two physiotherapy programmes in two Colombian universities, based on the formula for equivalency trials (27), in which size per group; normal two-tail standard deviation; acceptable difference; = standardized standard deviation of both comparison groups.

At the time of the study, the participants had taken a total of 87 credits and were actively enrolled in the participating programmes. The study excluded students <18 age, those who had been internally or externally transferred from another academic programme in health, exchange students, and those repeating and with prior experiences in simulated practice in other assignments.
The study established a stratified sampling by blocks in each university by using the Epidat program version 3.1 and assigning participants to one of the SP and RP groups, a procedure overseen by a professor not involved with the study. A record of the process was kept (Figure 1).
Result measurements
The study took into consideration the variables of gender, percentage of attendance of academic activities in SP and RP, level of bilingualism, score on the Colombian “SaberPro” state examination, and participants’ accumulated academic grade point average for their undergraduate formation.
The main outcome of this randomized control trial was Objective Structured Clinical Examination for low back pain (OSCE-LBP). It was applied in al blinded way at the start (week 0) and end of the period of the SP and RP interventions (week 8). This instrument was subjected to a content validity process with external experts in the study area (28). Application of the OSCE-LBP, as an evaluation process, was conducted by external professors to the research process to minimize evaluation bias. Training of the human resources applying the OSCE-LBP was carried out through systematic training in developing the OSCE-LBP in its different stages. Additionally, inter-rater correlation coefficient values were obtained (28), and the stages in which the professors had their best performance was identified compared with the denominated gold-standard evaluator (29).
The OSCE-LBP evaluates decision-making in clinical skills while caring for a person with LBP. It has seven stages each with a specific weight, assesses the skills or abilities described by the researchers regarding physiotherapeutic decision-making for a person with LBP, thus:
1) Physiotherapeutic examination (stage 1,2 and 3)
I. Anamnesis: recognizes the symptoms or antecedents including red flags and personal aspects that can guide decision making by physiotherapists in relation to LBP.
II. Revision by systems: recognizes physical symptoms that indicate red flags or signs of peripheral nerve involvement, or signs of LBP.
III. Tests and measurements: applies tests and measurements related to mobility, articular integrity, strength of the lumbo-pelvic complex, and the integrity of the peripheral nerves of the lumbo-pelvic region.
2) Physiotherapeutic evaluation (stage 4)
I. Explains to a person with LBP whether their condition is related to nociceptive LBP, neuropathic LBP or another type (central sensitization).
3) Diagnosis, prognosis and intervention plan (stage 4)
I. Proposes reachable objectives according to the characteristics of the person’s LBP.
II. Provides information to the patient about the treatment plan to follow according to findings obtained in the examination related with LBP prognosis.
III. Is clear with the language used and in line with previous aspects of the interaction process.
4) Intervention (stage 5, 6 and 7)
I. Includes therapeutic exercise according to the person’s needs and capacity.
II. Includes manual techniques according to the needs.
III. Includes specific physiotherapy techniques according to the needs.
IV. Includes interpretation of scientific evidence that supports the decision-making process (30–36).
5) Demonstrates patient centered-care and communication skills during the process of professional interaction (all stages).
I. Verbal, proxemic, paralinguistic and assertive tactile communication is demonstrated according to the performance context.
The results method of scoring the OSCE-LBP was established on a scale from 0.0 to 5.0. This scoring was obtained with a specific weight for each stage. It was given by a research team in percentages as shown: stage 1: 17%, stage 2: 12% Stage 3: 16%, stage 4: 15%, stage 5: 15%, stage 6: 13%, stage 7%: 12%. An equivalency success was determined in the SP and RP interventions with a difference of 0.8 (37).
Intervention
For both groups, the same pedagogic process was established to achieve the skills related to the interaction with people with LBP (described using the OSCE-LBP) in the following manner:
I. Learning guide process of therapeutic interaction with a person with LBP. The guide was distributed two weeks prior to conducting the SP or RP; its intention was to serve as a facilitator of the following phases of the learning process. The guide was constructed by the research team including in its first part information and independent activities for students to carry out a retrospective search about physiotherapeutic examinations and treatment for people with LBP supported in scientific evidence .
II. Development of skills through laboratory workshops for the prescription and application of manual techniques and therapeutic exercise for the health condition studied. Each group had 10 hours of classroom sessions prior to the SP or RP, with each session seeking to develop the practical aspects of the learning guide, which in the manual techniques included therapeutic massage (30), and superficial techniques of myofascial release for paravertebral muscles and related to the lumbo-pelvic complex (38). The exercise techniques included central stabilization exercises (39), analytic stretching and principles of postural re-education (40).
III. Simulation activity: for group one with standardized patient was constructed supported by a high fidelity guides in simulation training, which for this study is denominated SP. Group two was RP, using a methodology of low fidelity simulation.
The group denominated SP received a teaching strategy based on a class session with simulated practice for decision-making in clinical skills when caring for a person with LBP. Each session lasted approximately 120 minutes, and the clinical case used for the SP sessions was subjected to face validity with experts in the area of study.
Application of the simulated practice was conducted based on experiential knowledge of high fidelity simulation training, considering the following sequence of its elements:
- Context of the scenario: standardized for a clinical scenario of external consultation for the care of a person with LBP using physiotherapy.
- Patient standardization: based on the clinical case elaborated and validated, a script was created for the actor to interpret a person with LBP. Three simulated patients were trained per institution and their participation had a ratio of one patient for every eight students.
- Professor facilitator: a ratio was established of one professor for every eight students, and as in the case established, interpreted by the simulated patient, the professor started by approaching the person who was the object of care by following the characteristics of clinical reasoning.
- Guiding questions: the professor asked guiding questions that sought to stir reflection regarding the clinical situation observed, asking students to imagine other clinical situations and how the intervention would vary according to this.
- Concrete experience: students were permitted to interact with the simulated patient to carry out the reasoning process and thus provide care to the person.
- Debriefing: a meeting was held based on reflective conversation about the learning experience in which all the actors discussed the positive aspects and the learning opportunities. This process was mediated by dialogue and active listening; at the center of it were the students, who reflected on what they had done, and described their feelings and emotions, what was opportune, and what they would improve for subsequent opportunities with a person with LBP, this kind of data was not used for the purpose of this study.
The RP group, in turn, received a class session based on a “role-playing” simulation strategy, structured for the same purpose established in the SP group. This session lasted approximately 120 minutes, and the learning environment was the classroom in which students assumed different roles to act out; some of them acted like people with LBP and others as physiotherapists. The rolling-playing strategy not included specific training for acting like a patient. The study cases used for the RP group were different from SP group but with a similar level of complexity in LBP. The sequence of elements taken into account in RP group was:
- Division of the student's group into two: 1) physiotherapist and 2) patients.
- Three different case study were given to students case 1 was about pregnancy LBP, case two posttraumatic LBP, case three about nonspecific LBP.
- Both groups of students starting the acting process like physiotherapists or patients.
- At the end of the simulation, the students guided by a professor closed the simulation with a conclusion for each case study, in a not extensive way like the debriefing process in SP group.
Statistical analysis
Baseline: determined the distribution of the variables (extreme values, symmetries, kurtosis, types of distribution) ‒ for qualitative variables like gender, semester, University (table 1) were calculated relative frequencies (mode and erroneous data), and in all cases, evaluating the amount of data lost by each variable.
The quantitative variables like academic average over 5.0; credits taken according to Colombian educational system (1 credit equals to 48 hours per week in academic activities), bilingualism equal to the number of credits in the English language, and age in years. Those were described with a symmetric dispersion through medians and standard deviation.
To compare the effect of the magnitude, an analysis by intention to treat was performed. Initially, a difference of averages in the main outcome of the study OCSE between SP group and RP group. Also, was estimated the difference between the basal measurement and after the intervention. Thereafter, a comparison was made of the interventions through a two-level hierarchical model of random intercepts and fixed coefficients (level 2: university; level 1: subject). The model is described by the following.

Estimation of parameters was used with a 95% confidence level. Analyses were carried out using STATA version 14.