Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, La Jolla, CA, United States.
Moores Cancer Center, University of California, San Diego, San Diego, CA, United States.
JMIR Mhealth Uhealth. 2022 Jun 30;10(6):e37086. doi: 10.2196/37086.
There has been a rapid increase in the use of commercially available activity trackers, such as Fitbit, in physical activity intervention research. However, little is known about the long-term sustained use of trackers and behavior change after short-term interventions.
This study aims to use minute-level data collected from a Fitbit tracker for up to 2 years after the end of a randomized controlled trial to examine patterns of Fitbit use and activity over time.
Participants in this secondary data analysis were 75 female breast cancer survivors who had been enrolled in a 12-week physical activity randomized controlled trial. Participants randomized to the exercise intervention (full intervention arm) received a Fitbit One, which was worn daily throughout the 12-week intervention, and then were followed for 2 years after the intervention. Participants randomized to the waitlist arm, after completing the randomized controlled trial, received a Fitbit One and a minimal version of the exercise intervention (light intervention arm), and then were followed for 2 years after the intervention. Average and daily adherence and MVPA were compared between the 2 groups in the interventional and postinterventional periods using both linear and generalized additive mixed effects models.
Adherence to wearing the Fitbit during the 12-week intervention period was significantly higher in the full intervention arm than in the light intervention arm (85% vs 60%; P<.001). Average adherence was significantly lower for both study arms during the follow-up period than in the intervention period; however, there were statistically different patterns of adherence during the follow-up period, with the light intervention arm having steeper declines than the full intervention arm over time (P<.001). Similar to the adherence results, mean minutes of Fitbit-measured MVPA was higher for the full intervention arm than for the light intervention arm during the 12-week intervention period (mean MVPA 27.89 minutes/day, SD 16.38 minutes/day vs 18.35 minutes/day, SD 12.64 minutes/day; P<.001). During the follow-up period, average MVPA was significantly lower than the 12-week intervention period for both the full intervention arm (21.74 minutes/day, SD 24.65 minutes/day; P=.002) and the light intervention arm (15.03 minutes/day, SD 13.27 minutes/day; P=.004). Although the mean MVPA in each arm was similar across the follow-up period (P=.33), the pattern of daily MVPA was significantly different between the 2 groups (P<.001).
While adherence to wearing activity trackers and maintaining physical activities declined after completion of a 12-week exercise intervention, a more active interventional strategy resulted in greater wear time and activity levels during the intervention and more stable patterns of adherence and activity in the long term. An improved understanding of long-term maintenance patterns may inform improved exercise interventions that result in sustained increases in physical activity.
ClinicalTrials.gov NCT02332876; https://clinicaltrials.gov/ct2/show/NCT02332876.
随着 Fitbit 等商业化活动追踪器的广泛使用，其在体力活动干预研究中的应用迅速增加。然而，对于追踪器的长期持续使用以及短期干预后的行为变化，我们知之甚少。
本研究旨在利用 Fitbit 追踪器在随机对照试验结束后长达 2 年的分钟级数据，来检测随时间推移的 Fitbit 使用模式和活动水平。
这项二次数据分析的参与者是 75 名女性乳腺癌幸存者，她们参加了一项为期 12 周的体力活动随机对照试验。参与者被随机分配到运动干预组（完整干预组），他们在 12 周的干预期间每天佩戴 Fitbit One，然后在干预结束后再随访 2 年。被随机分配到候补组的参与者，在完成随机对照试验后，收到一个 Fitbit One 和一个最小版本的运动干预（轻度干预组），然后在干预结束后再随访 2 年。使用线性和广义加性混合效应模型比较了干预期和干预后期间两组之间的平均和日常依从性以及中高强度体力活动。
在 12 周的干预期间，完整干预组佩戴 Fitbit 的依从性明显高于轻度干预组（85%比 60%；P<.001）。在随访期间，两个研究组的依从性均明显低于干预期间；然而，在随访期间，依从性的模式存在统计学差异，随着时间的推移，轻度干预组的依从性下降速度快于完整干预组（P<.001）。与依从性结果相似，在 12 周的干预期间，完整干预组的 Fitbit 测量的中高强度体力活动的平均分钟数高于轻度干预组（平均 MVPA 27.89 分钟/天，SD 16.38 分钟/天比 18.35 分钟/天，SD 12.64 分钟/天；P<.001）。在随访期间，完整干预组（21.74 分钟/天，SD 24.65 分钟/天；P=.002）和轻度干预组（15.03 分钟/天，SD 13.27 分钟/天；P=.004）的平均 MVPA 均显著低于 12 周的干预期。尽管在随访期间每个组的平均 MVPA 相似（P=.33），但两组之间的日常 MVPA 模式差异显著（P<.001）。
虽然在完成 12 周的运动干预后，佩戴活动追踪器和维持体力活动的依从性下降，但更积极的干预策略导致干预期间佩戴时间和活动水平增加，长期依从性和活动模式更稳定。对长期维持模式的深入了解可能为改善运动干预提供信息，从而持续增加体力活动。
ClinicalTrials.gov NCT02332876；https://clinicaltrials.gov/ct2/show/NCT02332876。
