Impact of a Wearable Device-Based Walking Programs in Rural Older Adults on Physical Activity and Health Outcomes: Cohort Study.

BACKGROUND: Community-dwelling older adults living in rural areas are in a less favorable environment for health care compared with urban older adults. We believe that intermittent coaching through wearable devices can help optimize health care for older adults in medically limited environments. OBJECTIVE: We aimed to evaluate whether a wearable device and mobile-based intermittent coaching or self-management could increase physical activity and health outcomes of small groups of older adults in rural areas. METHODS: To address the above evaluation goal, we carried out the "Smart Walk" program, a health care model wherein a wearable device is used to promote self-exercise particularly among community-dwelling older adults managed by a community health center. We randomly selected older adults who had enrolled in a population-based, prospective cohort study of aging, the Aging Study of Pyeongchang Rural Area. The "Smart Walk" program was a 13-month program conducted from March 2017 to March 2018 and included 6 months of coaching, 1 month of rest, and 6 months of self-management. We evaluated differences in physical activity and health outcomes according to frailty status and conducted pre- and postanalyses of the Smart Walk program. We also performed intergroup analysis according to adherence of wearable devices. RESULTS: We recruited 22 participants (11 robust and 11 prefrail older adults). The two groups were similar in most of the variables, except for age, frailty index, and Short Physical Performance Battery score associated with frailty criteria. After a 6-month coaching program, the prefrail group showed significant improvement in usual gait speed (mean 0.73 [SD 0.11] vs mean 0.96 [SD 0.27], P=.02), International Physical Activity Questionnaire scores in kcal (mean 2790.36 [SD 2224.62] vs mean 7589.72 [SD 4452.52], P=.01), and European Quality of Life-5 Dimensions score (mean 0.84 [SD 0.07] vs mean 0.90 [SD 0.07], P=.02), although no significant improvement was found in the robust group. The average total step count was significantly different and was approximately four times higher in the coaching period than in the self-management period (5,584,295.83 vs 1,289,084.66, P<.001). We found that participants in the "long-self" group who used the wearable device for the longest time showed increased body weight and body mass index by mean 0.65 (SD 1.317) and mean 0.097 (SD 0.513), respectively, compared with the other groups. CONCLUSIONS: Our "Smart Walk" program improved physical fitness, anthropometric measurements, and geriatric assessment categories in a small group of older adults in rural areas with limited resources for monitoring. Further validation through various rural public health centers and in a large number of rural older adults is required.

Bactericidal activity in whole blood as a potential surrogate marker of immunity after vaccination against tuberculosis.

The development of new tuberculosis (TB) vaccines will require the identification of correlates of human protection. This study examined the balance between immunity and virulence in a whole blood infection model in which intracellular mycobacterial survival was measured using BACTEC. In the blood of tuberculin-negative donors, counts of Mycobacterium tuberculosis H(37)Ra organisms fell by 0.14 log(10) CFU during 96 h of whole blood culture, whereas counts of Mycobacterium bovis BCG, M. tuberculosis H(37)Rv, and a clinical TB isolate's organisms increased by 0.13, 0.43, and 1.04 log(10) CFU, respectively (P < 0.001), consistent with their relative virulence. Inhibition of tumor necrosis factor alpha by the addition of methylprednisolone or pentoxifylline or removal of CD4(+) or CD8(+) T cells by magnetic beads had deleterious effects on immune control of intracellular growth only in the blood of tuberculin-positive donors. Repeated vaccination of eight tuberculin-negative volunteers with M. bovis BCG resulted in a 0.3 log (50%) reduction in BCG CFU counts in the model compared to baseline values (P < 0.05). Three of the volunteers responded only after the second vaccination. These experiments indicate that whole blood culture may be used to measure immunity to M. tuberculosis and that further studies of repeated BCG vaccination are warranted.