Physical mobility is essential to health, and patients often rate it as a high-priority clinical outcome. Digital mobility outcomes (DMOs), such as real-world gait speed or step count, show promise as clinical measures in many medical conditions. However, current research is nascent and fragmented by discipline. This scoping review maps existing evidence on the clinical utility of DMOs, identifying commonalities across traditional disciplinary divides. In November 2019, 11 databases were searched for records investigating the validity and responsiveness of 34 DMOs in four diverse medical conditions (Parkinson’s disease, multiple sclerosis, chronic obstructive pulmonary disease, hip fracture). Searches yielded 19,672 unique records. After screening, 855 records representing 775 studies were included and charted in systematic maps. Studies frequently investigated gait speed (70.4% of studies), step length (30.7%), cadence (21.4%), and daily step count (20.7%). They studied differences between healthy and pathological gait (36.4%), associations between DMOs and clinical measures (48.8%) or outcomes (4.3%), and responsiveness to interventions (26.8%). Gait speed, step length, cadence, step time and step count exhibited consistent evidence of validity and responsiveness in multiple conditions, although the evidence was inconsistent or lacking for other DMOs. If DMOs are to be adopted as mainstream tools, further work is needed to establish their predictive validity, responsiveness, and ecological validity. Cross-disciplinary efforts to align methodology and validate DMOs may facilitate their adoption into clinical practice.

Introduction Physical activity (PA) is reduced in patients with interstitial lung disease (ILD) and chronic obstructive pulmonary disease (COPD). Evidence about the PA pattern of patients with ILD is scarce. If PA of patients with ILD would be comparable to COPD, it is tempting to speculate that existing interventions focusing on enhancing PA could be as effective in ILD as already shown in COPD. Therefore, we aimed to compare PA and the correlates with PA in matched patients with ILD, COPD, and healthy subjects. Materials and methods Patients with ILD (n = 45), COPD (n = 45) and healthy subjects (n = 30) were propensity matched. PA level, pattern, and PA correlations with lung function and physical performance (6-minute walking distance and quadriceps force) were compared between groups. Results Daily number of steps was similar in both patient groups (mean±SE: 5631±459 for ILD, 5544±547 for COPD, p = 0.900), but significantly lower compared to healthy subjects (10031±536, p<0.001 for both). Mean intensity of PA tended to be lower in the ILD group (mean±SE metabolic equivalents of task per day: 1.41±0.04) compared to COPD (1.52±0.05, p = 0.074) and healthy individuals (1.67±0.04, p<0.001). The pattern of PA over one day was found to be similar between the three groups. Lastly, the correlation between PA and 6-minute walking distance was significantly weaker in patients with ILD compared to patients with COPD (respectively r = 0.348 and r = 0.739; p<0.05 for both). Conclusions For a given functional reserve, patients with ILD perform an equal amount of steps but perform PA at lower intensity compared to patients with COPD. Both groups are less active compared to healthy control subjects. Functional exercise capacity was shown to be only moderately related to PA. This can potentially influence the effectiveness of PA interventions that can be expected.

No abstract

No abstract

No abstract