Validation of the OPTIMAL-Confidence Questionnaire in Patients with Chronic Low Back Pain

Background/Objectives: Low back pain is one of the most prevalent pathologies. Several studies relate its chronification to certain psycho-emotional characteristics, such as self-efficacy or the patient's lack of confidence in the ability to move. Determine the reliability and validity of the OPTIMAL-confidence scale in people with chronic low back pain and describe the confidence in the movement capacity of this population. Methods: Design: A validation study was designed to evaluate the psychometric properties of the OPTIMAL-Confidence Questionnaire in a population with chronic low back pain. A descriptive observational study in a population with chronic low back pain and a healthy population was designed to describe the confidence in the movement capacity of the population with chronic low back pain. Settings: Health centers of primary care from a region of northwestern Spain. Participants: The final sample was 122 patients diagnosed with chronic low back pain. The sampling was completed with 30 additional healthy subjects. Instruments: OPTIMAL-confidence questionnaire, Numerical Pain Rating Scale, Chronic Pain Self-efficacy Scale, and ad hoc questionnaire to collect socio-demographic and clinical variables. Results: Cronbach's alpha for the OPTIMAL-confidence questionnaire was 0.91. The association of OPTIMAL-confidence with the self-efficacy, pain intensity, and movement ability scales was moderate and significant (p < 0.001). Regarding the low back pain population, significant differences were observed in confidence levels according to age and the need for walking aids (p < 0.009). The OPTIMAL-confidence questionnaire also showed significant discrimination between the low back pain group and the no back pain group (p < 0.001). The confidence interval was 95%. Conclusions: The population with low back pain shows less confidence in their ability to perform movements, compared to the general population. OPTIMAL is an instrument that can discriminate between patients who present chronic low back pain and those who do not.