Anderssen N, Jacobs D R, Sidney S, Bild D E, Sternfeld B, Slattery M L, Hannan P
Center for Health Promotion, University of Bergen, Norway.
Am J Epidemiol. 1996 Feb 15;143(4):351-62. doi: 10.1093/oxfordjournals.aje.a008749.
Levels and changes in self-reported physical activity over a 7-year period were examined to determine tracking and to estimate the proportion of total cohort change attributable to secular trends. A population-based sample of 2,328 men and 2,787 women aged 18-30 years at baseline (52% black and 48% white) from Birmingham, Alabama, Chicago, Illinois, Minneapolis, Minnesota, and Oakland, California, were examined four times between 1985-1986 and 1992-1993. The intraclass correlation for up to four measures was 0.57 for the entire sample, varying between 0.57 for white men and 0.42 for black women, indicating a moderate tendency for tracking. The energy expenditure in physical activity at each examination was greatest in black men and, compared with black men, about 5% less in white men, 30% less in white women, and 50% less in black women. The total cohort decrease in mean physical activity was approximately 30% in each race-sex group. The secular trend accounted for 38% of the total cohort change in black men, 43% in black women, 52% in white men, and 81% in white women. Physical activity declined sharply during the early years of adulthood, partly because of secular trend. Young adults are therefore an important target group for physical activity promotion programs to reverse individual and populationwide declines prior to middle age.
对7年期间自我报告的身体活动水平及其变化进行了检查，以确定其追踪情况，并估计整个队列变化中可归因于长期趋势的比例。从阿拉巴马州伯明翰、伊利诺伊州芝加哥、明尼苏达州明尼阿波利斯和加利福尼亚州奥克兰选取了一个基于人群的样本，样本包括2328名基线年龄在18 - 30岁的男性和2787名女性（52%为黑人，48%为白人），在1985 - 1986年至1992 - 1993年期间进行了四次检查。整个样本中多达四项测量的组内相关系数为0.57，白人男性为0.57，黑人女性为0.42，表明追踪趋势中等。每次检查时身体活动的能量消耗在黑人男性中最大，与黑人男性相比，白人男性少约5%，白人女性少30%，黑人女性少50%。每个种族-性别组的队列平均身体活动总降幅约为30%。长期趋势在黑人男性队列变化中占38%，黑人女性中占43%，白人男性中占52%，白人女性中占81%。成年早期身体活动急剧下降，部分原因是长期趋势。因此，年轻人是身体活动促进项目的重要目标群体，以便在中年之前扭转个体和全人群的身体活动下降趋势。
