Newschaffer C J, Bush T L, Hale W E
Department of Epidemiology, Johns Hopkins University School of Hygiene and Public Health, Baltimore, MD 21205.
Am J Epidemiol. 1992 Jul 1;136(1):23-34. doi: 10.1093/oxfordjournals.aje.a116417.
This analysis describes the association of age with the serum total cholesterol level in 5,010 participants in a geriatric health screening program. Cholesterol levels were measured annually in participants monitored for up to 12 years. The association of age with cholesterol level is described via three approaches: cross-sectional analysis, descriptive longitudinal analysis, and longitudinal analysis using statistical modeling. The results were compared to examine the influence of cohort, period, and survivorship effects on the association between age and cholesterol. In cross-sectional analysis, the cholesterol level was fairly constant for the ages of 65 to 75 years, but decreased by 21% over the age range from 75 to 95 years. Descriptive longitudinal analysis suggested that both cohort and period effects were influencing the cross-sectional findings. In longitudinal analysis adjusting for both cohort and period effects, the findings were similar to those from cross-sectional analysis for the ages of 65 to 75 years, but from the ages of 75 to 95 years, cholesterol decreased by only 9%--half as great a decline as that estimated from cross-sectional analysis. When longitudinal data were limited to those with complete follow-up, the predicted decline for the age range from 75 to 95 years was only 6%. Although this flattening of the age trend was suggestive, there was no conclusive evidence that it reflected an association between baseline cholesterol and loss to follow-up.
该分析描述了一项老年健康筛查项目中5010名参与者的年龄与血清总胆固醇水平之间的关联。对参与者进行了长达12年的监测，每年测量胆固醇水平。通过三种方法描述年龄与胆固醇水平之间的关联：横断面分析、描述性纵向分析以及使用统计模型的纵向分析。对结果进行比较，以检验队列、时期和生存效应对年龄与胆固醇之间关联的影响。在横断面分析中，65至75岁年龄段的胆固醇水平相当稳定，但在75至95岁年龄段下降了21%。描述性纵向分析表明，队列效应和时期效应都在影响横断面研究结果。在对队列效应和时期效应进行调整的纵向分析中，65至75岁年龄段的结果与横断面分析相似，但在75至95岁年龄段，胆固醇仅下降了9%，降幅仅为横断面分析估计值的一半。当纵向数据仅限于随访完整的人群时，75至95岁年龄段的预测降幅仅为6%。尽管年龄趋势的这种平缓具有一定暗示性，但没有确凿证据表明它反映了基线胆固醇与失访之间的关联。
