Xu X, Weiss S T, Dockery D W, Schouten J P, Rijcken B
Department of Environmental Science and Physiology, Harvard School of Public Health, Boston, MA, USA.
Chest. 1995 Sep;108(3):656-62. doi: 10.1378/chest.108.3.656.
Data collected in two large-scale longitudinal respiratory studies were analyzed to estimate age-related changes in FEV1 and to determine the between-study differences in change in FEV1 among nonsmoking participants. Two adult cohorts in the Netherlands were followed up for 21 years at 3-year intervals and a cohort of adults in 6 cities in the eastern United States was followed up for 6 years. The age distributions and follow-up rate differed for the two studies. The mean rates of decline in FEV1 for 50-year old male and female never smokers were 27.9 +/- 2.8 mL/yr and 22.1 +/- 0.9 mL/yr, respectively, in the Netherlands cohort. The estimates for men and women in the Six Cities cohort were 33% and 32% greater, respectively, than those for the Netherlands cohort (p < 0.01). The estimated rate of decline in FEV1 associated with each 1-year increase in age was 0.50 +/- 0.12 mL/yr for men and 0.61 +/- 0.08 mL/yr for women in the Netherlands cohort. This estimate was comparable for the Six Cities women and the Netherlands women but significantly different for the two cohorts of men. Inclusion of survey (period) effect in the regression model had only a trivial influence on accelerated rate of decline in FEV1 and did not alter the more rapid acceleration of decline in FEV1 among the Six Cities men. The present study also showed that use of a "prediction equation" for age adjustment to compare across population samples may produce a biased conclusion if the estimated rate of decline in FEV1 associated with age is different and the age distributions are different for the two populations. In addition, height adjustment for FEV1 was found to have a negligible influence on the longitudinal estimates of FEV1 decline in both study samples. In conclusion, substantial between study variation in decline in FEV1 occurs despite use of similar data analysis techniques. Differences in the initial age distributions and loss to follow-up appeared to be important factors in this analysis.
对两项大规模纵向呼吸研究收集的数据进行了分析，以估计第一秒用力呼气容积（FEV1）与年龄相关的变化，并确定非吸烟参与者中FEV1变化的研究间差异。荷兰的两个成年队列每3年随访一次，为期21年；美国东部6个城市的一个成年队列随访了6年。两项研究的年龄分布和随访率有所不同。在荷兰队列中，50岁男性和女性从不吸烟者的FEV1平均下降率分别为27.9±2.8毫升/年和22.1±0.9毫升/年。六城市队列中男性和女性的估计值分别比荷兰队列高33%和32%（p<0.01）。在荷兰队列中，年龄每增加1岁，FEV1的估计下降率男性为0.50±0.12毫升/年，女性为0.61±0.08毫升/年。六城市队列中的女性和荷兰队列中的女性的这一估计值相当，但两个男性队列之间存在显著差异。在回归模型中纳入调查（时期）效应，对FEV1下降加速率的影响微不足道，并未改变六城市队列男性中FEV1下降加速更快的情况。本研究还表明，如果两个总体中与年龄相关的FEV1下降估计率不同且年龄分布不同，那么使用“预测方程”进行年龄调整以比较不同人群样本可能会得出有偏差的结论。此外，发现对FEV1进行身高调整对两个研究样本中FEV1下降的纵向估计影响可忽略不计。总之，尽管使用了相似的数据分析技术，但FEV1下降情况在研究间仍存在很大差异。初始年龄分布和随访失访的差异似乎是该分析中的重要因素。
