ABSTRACT
Purpose: Current walking interventions for people with knee osteoarthritis (OA) focus on either reducing knee joint loading or on increasing physical activity. There is a need for interventions that could address both quality and quantity of walking for people with knee OA. The goal of this randomized controlled trial (clinicaltrials.gov # NCT03064139) was to determine the feasibility of a mindful walking intervention to improve quality and quantity of walking in people with knee OA. Methods: Individuals with symptomatic knee OA were recruited from the community using advertisements. Study criteria are shown in Table 1. [Formula presented] During enrollment, the more symptomatic knee, or a knee selected at random in case of equal symptoms, was designated as the study knee. After the baseline visit, participants were randomized to either a mindful walking group (MWG) or an attention-matched self-management group (SMG). Participants in both groups received 11 intervention sessions delivered over a 6-month period (4 in 1 st month, 2 each in 2nd and 3rd months, 1 each in 4th, 5th, and 6th months). Interventions were delivered via in-person groups (4-10 in each group) and each session was 1.5-3 hours in duration. For MWG, a certified instructor provided training in mindful walking that includes whole-body movement retraining and mindful body-awareness skill building. Biomechanical elements include: shorter stride length, higher cadence, greater toe-in, and more aligned posture. Participants were coached to progressively increase their mindful walking activity each week. Mindfulness elements include mindful body-awareness skills to increase sensitivity and awareness of deviations from the taught techniques. The approach is based on “ChiWalking®” so called because the movement approaches are drawn in part from T’ai Chi. For SMG, a researcher delivered a curriculum consisting of education and self-management techniques (e.g., importance of physical activity and exercise, nutrition, weight-management, etc.). This information was also provided to MWG in a condensed form. Gait analyses and physical performance tests were completed at baseline and 6-months. Physical activity was assessed using a commercial wrist-worn activity monitor (Charge 3, Fitbit Inc, San Francisco, CA). Participant-reported outcomes (PROs) were completed at baseline and every 3-months. Participants were remotely followed for an additional 6-months after the end of the intervention. Given the feasibility nature of the study, primary outcomes included recruitment, adherence, retention and number of adverse events. Secondary outcomes included peak external knee adduction moment [KAM], daily step count, Knee injury and osteoarthritis outcome score (KOOS) Pain, Five Facet Mindfulness Questionnaire (FFMQ), Arthritis Self-Efficacy Scale (ASES), 30-second chair stand test (30STS), 40-meter fast paced walk test (40FPW), and Stair Climbing Test (SCT). Analyses were conducted on intention-to-treat basis with all randomized participants included and missing values were not imputed. Results: Participants were recruited between March 2019 and January 2020. During this period, ∼450 individuals completed pre-screening questionnaires (∼41 per month), 66 completed in-person screening visits, 47 were enrolled, and 44 were randomized (Table 2). Interventions for 19 participants were interrupted, delayed for 3-months, and then transitioned to virtual format due to the COVID-19 pandemic. While the original recruitment goal was 62, the trial was halted earlier due to COVID-19. [Formula presented] Attendance is shown in Table 3. On average, MWG group attended 63% of the sessions vs. 70% in the SMG group. Among those who attended at least 1 session, MWG group attended 69% vs. 77% for SMG. Among those who attended at least 3 sessions, MWG group attended 75% vs. 84% for SMG. Post-intervention, 65% (n=15) and 87% (n=20) of MWG completed the in-person visits and PROs, respectively. In SMG, 81% (n=17) completed in-person visits and PROs. At 12-months, 91% (n=21) and 71% (n 15) completed the PROs for MWG and SMG, respectively. [Formula presented] Participant feedback at 6- and 12-months showed that the intervention was acceptable (Table 4). There were no serious adverse events related to the intervention in either group. Within group and between group differences for secondary outcomes are shown in Table 5. [Formula presented] [Formula presented] Conclusions: Our benchmarks were recruitment over 1.5 years, attendance of 75% in MWG group, and retention of 80% of participants at 6-months. While all of these benchmarks were negatively impacted by COVID-19, the recruitment rates over the period studied, adherence in those who attended at least 3 sessions, and retention for some secondary outcomes were acceptable. Participants in both groups found the interventions helpful, enjoyable, and rated it highly. At 12-month follow-up, MWG participants continued to practice mindful walking 1-2 days a week. Between group differences for secondary outcomes were small. Given the feasibility nature of the study, conclusions regarding efficacy cannot be made and larger trial would be needed. Our results show that our methods are appropriate for conducting such a larger trial.
ABSTRACT
Purpose: The COVID-19 pandemic has accelerated the adoption of digital health technologies for remote monitoring of participants in clinical trials, including measuring physical function. For trials in people with knee osteoarthritis (OA), standardized measures of function such as gait and chair stand are considered important outcomes. Wearable sensors have the potential to monitor these outcomes remotely. However, the reliability of wearable sensor metrics of gait and chair stand in participants’ homes and agreement between these metrics collected in laboratory and at-home have not been reported to date. Hence, our objective was to assess the reliability of wearable sensors for remote monitoring of gait and chair stand in people with knee OA. Methods: We used data from a substudy (n=20) embedded within an ongoing, single-arm clinical trial of an exercise intervention in people with knee OA (clinicaltrials.gov NCT04243096). Key inclusion criteria were age ≥ 50, BMI ≤ 40 kg/m2, physician diagnosed knee OA, score ≥ 3 on weight-bearing questions from the Knee Injury and Osteoarthritis Outcome Score (KOOS) Pain Subscale in the index knee, and ability to walk for 20 minutes without assistance. Key exclusion criteria included other major health conditions;prior, current, or planned major knee OA treatment;prior surgeries for knee OA;and contraindications to exercise. All assessments took place prior to initiation of the intervention. Participants completed two visits, an in-person lab visit and a remote at-home visit. The order of these visits was randomized across participants, with participants completing both visits between 1 and 20 days of each other. For the remote visit, participants were provided a wearable system consisting of three inertial sensors (Opal, APDM, Portland, OR, USA), two cones connected by a 7-meter rope, and an armless chair. Identical equipment was used during the in-person lab visit. During the remote visit, researchers guided the participants via video conference. Participants self-applied the sensors on each foot and on the lower back. They performed two trials each of a standardized gait task (self-selected walk for two laps of a 7-meter path defined by the cones and rope totaling 28 meters of walking) and chair stand task (five chair stands as quickly as possible with arms across the chest) in their home. Then, the participants removed the sensors, waited 15-minutes, re-applied the sensors, and performed two more trials of each task. At the end of the remote visit, participants completed a survey on their experience. During the in-person lab visit, participants performed two trials of the same tasks after a researcher placed the sensors on the participants. Spatiotemporal metrics of gait function and duration of chair stand were extracted from the sensor data using software (MoveoExplorer) provided by the sensor manufacturer. The mean of sensor metrics across each set of two trials were used in the analyses. We used Pearson’s correlation R2 and the intra-class correlation coefficients (ICC) to determine the correlation and the test-retest reliability of sensor metrics from the two repetitions of the tasks during the remote visit. We used ICCs and Bland-Altman plots and their 95% limits of agreement to examine agreement between sensor metrics from the remote (first two trials) and lab visits. Results: Participant characteristics are shown in Table 1. All ICCs were good to excellent (between 0.85 and 0.96) for the test-retest reliability during the remote visit and R2 ranged between 0.81 and 0.95 (Table 2, Figure 1). ICCs were moderate to excellent (between 0.63 and 0.91) for agreement between remote and lab visits (Table 2). Bland-Altman plots showed small bias in all metrics due to participants walking slightly faster during the lab visit compared to the remote visit (Figure 2). Participants were highly accepting of the remote visit (Table 3). Conclusions: In this cohort of people with knee OA who had moderate pain and disability, our method of estimating gait and chair stand fu ction remotely was found to be reliable, feasible, and acceptable. Wearable sensors could be used to remotely monitor gait and chair stand function in participant’s natural environments at a lower cost, reduced participant and researcher burden, and greater ecological validity overcoming many limitations of lab visits. Hence, our approach could be used in future clinical trials of people with knee OA. [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented]