Medición de la calidad del trato al usuario tras la introducción del asistente-alumno en centros de salud familiar en Chile marceLo concha i. a , aLan hirschBerg g. a , nicoLás arraño r. a , marceLa cárcamo i. 1,b , Jaime mañaLich m. 1 Effect of the presence of student-assistants on the quality of care perception by ambulatory patients Background: The time dedicated to patients and how they are treated are crucial in the evaluation of health care quality. Medical students acting as medical assistants could improve the perception of a good quality of care among ambulatory patients. Aim: To evaluate if the presence of Student-Assistants improves the patients' perception of health care quality in ambulatory primary care. Patients and Methods: Quasi-experimental exploratory study. In two health care centers, patients answered a questionnaire about their perception of how they were treated at baseline and after an intervention period. In one center, prior to the appointment of the patient with the doctor, the student interviewed patients focusing on chief complaints and registered their vital signs, orally presenting this information to the clinician. In the other center, there was no student intervention. Patients answered the questionnaire at the end of appointments. Results: At baseline 103 patients answered the questionnaire (58 in the experimental and 45 in the control center). After the intervention, 121 patients answered it (56 in the experimental and 65 in the control center). Basal scores were 6,25 and 6,06 in experimental and control center, respectively (p = NS). After the intervention, the scores were 6,49 and 6,15, respectively (p = 0,01). Conclusions: These data support the hypothesis that the presence of a Student-Assistant could improve the perception of patients about how they are treated at primary health care centers.