Behavioral Epidemiology, Baker Heart and Diabetes Institute, Melbourne, Victoria, AUSTRALIA.
Med Sci Sports Exerc. 2021 Feb 1;53(2):316-323. doi: 10.1249/MSS.0000000000002479.
Long-term effects of physical activity and television (TV) viewing on mortality have been inferred from observational studies. The associations observed do not allow for inferences about the effects of population interventions and could be subject to bias due to time-varying confounding.
Using data from the Australian Diabetes, Obesity and Lifestyle Study, collected in 1999-2000 (T0), 2004-2005 (T1), and 2011-2012 (T2), we applied the parametric g-formula to estimate cumulative risks of death under hypothetical interventions on physical activity and/or TV viewing determined from self-report while adjusting for time-varying confounding.
In the 6377 participants followed up for 13 yr from 2004 to 2005 to death or censoring in 2017, 781 participants died. The observed cumulative risk of death was 12.2%. The most effective hypothetical intervention was to increase weekly physical activity to >300 min (risk ratio (RR), 0.66 (0.46-0.86) compared with a "worst-case" scenario; RR, 0.83 (0.73-0.94) compared with no intervention). Reducing daily TV viewing to <2 h in addition to physical activity interventions did not show added survival benefits. Reducing TV viewing alone was least effective in reducing mortality (RR, 0.85 (0.60-1.10) compared with the worst-case scenario; RR, 1.06 (0.93-1.20) compared with no intervention).
Our findings suggested that sustained interventions to increase physical activity could lower all-cause mortality over a 13-yr period, and there might be limited gain from intervening to reduce TV viewing time in a relatively healthy population.
从观察性研究中推断出身体活动和电视（TV）观看对死亡率的长期影响。观察到的关联不允许对人群干预的效果进行推断，并且由于时变混杂，可能存在偏差。
我们使用澳大利亚糖尿病、肥胖和生活方式研究（Australian Diabetes, Obesity and Lifestyle Study）的数据，这些数据是在 1999-2000 年（T0）、2004-2005 年（T1）和 2011-2012 年（T2）收集的，我们应用参数 g 公式来估计在自我报告的身体活动和/或电视观看假设干预下的死亡累积风险，同时调整了时变混杂。
在 2004 年至 2005 年期间随访 13 年至 2017 年死亡或删失的 6377 名参与者中，有 781 名参与者死亡。观察到的死亡累积风险为 12.2%。最有效的假设干预是将每周身体活动增加到>300 分钟（风险比（RR），0.66（0.46-0.86）与“最坏情况”相比；RR，0.83（0.73-0.94）与无干预相比）。除了身体活动干预外，将每天看电视时间减少到<2 小时并没有显示出额外的生存益处。单独减少看电视的效果最低（RR，0.85（0.60-1.10）与最坏情况相比；RR，1.06（0.93-1.20）与无干预相比）。
我们的研究结果表明，持续的身体活动干预可能会降低在 13 年内的全因死亡率，而在相对健康的人群中干预减少看电视时间可能不会有太大的获益。
