Validity of the FitBit flex and accelerometer to estimate number of steps of patients with nonspecific chronic low back pain

• Grant number: 18/23290-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2019
• End date: June 30, 2020
• Field of knowledge: Health Sciences - Collective Health - Public Health
• Principal Investigator: Diego Giulliano Destro Christofaro
• Grantee: Caio Cantarela Cunha
• Host Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

Low back pain is among the most prevalent musculoskeletal conditions worldwide and the leading cause of years lived with disability. In fact, clinical practice guidelines recommend physical activity-based interventions for patients with chronic low back pain. Two methods are used to measure the physical activity levels: self-report and objective methods. However, the self-report methods are prone to some type of bias, including recall bias, social desirability, and psychosocial factors. Among the instruments to measure objective physical activity levels, accelerometers and the Fitbit have been commonly used in clinical practice. Although recent studies demonstrated that some Fitbit models (e.g. Zip) are valid to estimate number of steps and measure physical activity levels of healthy people, no study investigated the validity of the Fitbit Flex and the accelerometer compared to step counter in patients with chronic low back pain. Objective: to investigate the validity of the Fitbit Flex and the accelerometer compared to the step counter to estimate number of steps in patients with chronic low back pain. Methods: Participants aged between 18 to 60 years with non-specific chronic low back pain, defined as pain lasting more than three months without any attributable cause, will be considered eligible for this study. Seventy participants will be included in this study. Each participant will attend to the physiotherapy clinic twice, with a one week interval. Firstly, the participants will complete the baseline assessment and perform a 6-min walk test using the accelerometer in the right waist and the Fitbit Flex in the non-dominant wrist to be compared with the step counter used by the physiotherapists. To assess the equivalence between the Fitbit Flex, accelerometer, and step counter will be used the Interclass Coefficient Correlation (ICC2,1) with 95% of confidence intervals. To analyses the systematic differences between the instruments, we will use the Bland Altman plot.