Background In the absence of a vaccine or effective treatment for COVID-19, countries have adopted nonpharmaceutical interventions (NPIs) such as social distancing and full lockdown. An objective and quantitative means of passively monitoring the impact and response of these interventions at a local level is needed. Objective We aim to explore the utility of the recently developed open-source mobile health platform Remote Assessment of Disease and Relapse (RADAR)–base as a toolbox to rapidly test the effect and response to NPIs intended to limit the spread of COVID-19. Methods We analyzed data extracted from smartphone and wearable devices, and managed by the RADAR-base from 1062 participants recruited in Italy, Spain, Denmark, the United Kingdom, and the Netherlands. We derived nine features on a daily basis including time spent at home, maximum distance travelled from home, the maximum number of Bluetooth-enabled nearby devices (as a proxy for physical distancing), step count, average heart rate, sleep duration, bedtime, phone unlock duration, and social app use duration. We performed Kruskal-Wallis tests followed by post hoc Dunn tests to assess differences in these features among baseline, prelockdown, and during lockdown periods. We also studied behavioral differences by age, gender, BMI, and educational background. Results We were able to quantify expected changes in time spent at home, distance travelled, and the number of nearby Bluetooth-enabled devices between prelockdown and during lockdown periods (P<.001 for all five countries). We saw reduced sociality as measured through mobility features and increased virtual sociality through phone use. People were more active on their phones (P<.001 for Italy, Spain, and the United Kingdom), spending more time using social media apps (P<.001 for Italy, Spain, the United Kingdom, and the Netherlands), particularly around major news events. Furthermore, participants had a lower heart rate (P<.001 for Italy and Spain; P=.02 for Denmark), went to bed later (P<.001 for Italy, Spain, the United Kingdom, and the Netherlands), and slept more (P<.001 for Italy, Spain, and the United Kingdom). We also found that young people had longer homestay than older people during the lockdown and fewer daily steps. Although there was no significant difference between the high and low BMI groups in time spent at home, the low BMI group walked more. Conclusions RADAR-base, a freely deployable data collection platform leveraging data from wearables and mobile technologies, can be used to rapidly quantify and provide a holistic view of behavioral changes in response to public health interventions as a result of infectious outbreaks such as COVID-19. RADAR-base may be a viable approach to implementing an early warning system for passively assessing the local compliance to interventions in epidemics and pandemics, and could help countries ease out of lockdown.

Objective:To determine the effectiveness of high-efficacy disease-modifying therapies (heDMT) versus medium-efficacy disease-modifying therapies (meDMT) as the first treatment choice in treatment-naïve patients with multiple sclerosis (MS) on disability worsening and relapses. We assessed this using a nationwide population-based MS registry.Methods:We identified all patients starting a heDMT as first-time treatment from the Danish Multiple Sclerosis Registry and compared treatment outcomes with a propensity-score matched sample of patients starting meDMT.Results:We included 388 patients in the study: 194 starting initial therapy with heDMT matched to 194 patients starting meDMT. At 4 years of follow-up, the probabilities of a 6-month confirmed Expanded Disability Status Scale (EDSS) score worsening were 16.7% (95% confidence interval (CI): 10.4%-23.0%) and 30.1% (95% CI: 23.1%-37.1%) for heDMT- and meDMT-initiators, respectively (Hazard ratio (HR): 0.53, 95% CI 0.33-0.83, p=0.006). Patients initiating heDMT also had a lower probability of a first relapse (HR 0.50, 95% CI 0.37-0.67). Results were similar after pairwise censoring and in subgroups with high-baseline activity, diagnosis after year 2006 or information on baseline T2 lesion load.Conclusion:We found a lower probability of 6-month confirmed EDSS score worsening and lower probability of a first relapse in patients starting a heDMT as first therapy, compared to a matched sample starting meDMT.Classification of Evidence:This study provides Class III evidence that for patients with MS, starting heDMT lowers the risk of EDSS worsening and relapses compared to starting meDMT.