CIDEFES, Universidade Lusófona, Lisbon, Portugal.
Early Start, University of Wollongong, Wollongong, NSW, Australia.
J Prev (2022). 2023 Jun;44(3):291-307. doi: 10.1007/s10935-023-00724-4. Epub 2023 Jan 24.
Screen time shows higher health risks compared to other types of sedentary behaviors. A lockdown may simultaneously increase screen time, reduce physical activity (PA), and change time perception. Our goal was to compare self-reported against objectively measured smartphone screen time (SST) in a sample of active and inactive Portuguese adults before and during a social lockdown. This study was a cross-sectional analysis with 211 Portuguese adults (57.8% males), aged 25.2 ± 8.5 years, from two cohorts, one before the social lockdown and the other during the lockdown. SST was self-reported (SR-SST) and objectively measured using a smartphone (OM-SST). PA was self-reported. Linear regressions were performed to determine the association between SR-SST and OM-SST. A Bland and Altman analysis was used to assess agreement. Independent T-tests were performed for comparisons between cohorts and paired sample T-tests for comparisons within each cohort. The cohort assessed during the lockdown showed a higher SST than the cohort assessed before the lockdown (OM-SST; p < 0.001 and SR-SST; p = 0.009). Before the lockdown, there was no difference between SR-SST and OM-SST (p = 0.100). However, during the social lockdown, although the agreement between SR-SST and OM-SST was good (ICC = 0.72), participants systematically underestimated their SST by ~ 71 min/day (p < 0.001), and this underestimation was higher in inactive participants (~ 85 min/day) than in active individuals (~ 49 min/day). The general population needs to be aware of the benefits of limiting screen time, especially during periods of societal modifications, such as a generalized lockdown. There was a tendency to underestimate SST, meaning a lack of awareness of the actual time spent in this potentially deleterious behavior. This underestimation was more pronounced during the lockdown period and for the inactive participants, thus posing a greater health risk. The findings from this investigation entail relevant information for policy makers to delineate strategies for reducing population screen time from a preventive health perspective.
与其他类型的久坐行为相比，屏幕时间显示出更高的健康风险。封锁可能会同时增加屏幕时间，减少体力活动（PA），并改变时间感知。我们的目标是比较活跃和不活跃的葡萄牙成年人在社交封锁前后，通过自我报告和客观测量智能手机屏幕时间（SST）的样本。这项研究是一项横断面分析，共有 211 名葡萄牙成年人（57.8%为男性），年龄 25.2 ± 8.5 岁，来自两个队列，一个在社交封锁之前，另一个在封锁期间。SST 通过智能手机进行自我报告（SR-SST）和客观测量（OM-SST）。PA 通过自我报告。进行线性回归以确定 SR-SST 和 OM-SST 之间的关联。Bland 和 Altman 分析用于评估一致性。进行独立 T 检验比较队列之间的差异，进行配对样本 T 检验比较每个队列内的差异。在封锁期间评估的队列显示出比封锁前评估的队列更高的 SST（OM-SST；p<0.001 和 SR-SST；p=0.009）。在封锁之前，SR-SST 和 OM-SST 之间没有差异（p=0.100）。然而，在社交封锁期间，尽管 SR-SST 和 OM-SST 之间的一致性很好（ICC=0.72），但参与者每天系统地低估其 SST 约 71 分钟（p<0.001），并且这种低估在不活跃的参与者中更高（85 分钟/天）比活跃的个体（49 分钟/天）。普通大众需要意识到限制屏幕时间的好处，特别是在社会调整期间，例如全面封锁。人们有一种倾向于低估 SST，这意味着他们对这种潜在有害行为实际花费的时间缺乏认识。这种低估在封锁期间更为明显，对于不活跃的参与者而言，这构成了更大的健康风险。从这个调查中得出的发现为政策制定者提供了相关信息，以便从预防健康的角度制定减少人口屏幕时间的策略。
