越老越好：老年研究参与者的代表性越差吗？一项临床试验和观察性研究样本的横断面分析。

The older the better: are elderly study participants more non-representative? A cross-sectional analysis of clinical trial and observational study samples.

机构信息

Department of Medicine, University of California, San Diego, California, USA.

出版信息

BMJ Open. 2012 Dec 14;2(6). doi: 10.1136/bmjopen-2012-000833. Print 2012.

DOI:10.1136/bmjopen-2012-000833

PMID:23242479

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC3533104/

Abstract

OBJECTIVE

Study participants can differ from the target population they are taken to represent. We sought to investigate whether older age magnifies such differences, examining age-trends, among study participants, in self-rated level of activity compared to others of the same age.

DESIGN

Cross-sectional examination of the relation of participant age to reported 'relative activity' (ie, compared to others of the same age), a bidirectionally correlated proxy for relative vitality, in exemplars of randomised and observational studies.

SETTING

University of California, San Diego (UCSD) PARTICIPANTS: 2404 adults aged 40-79 including employees of UCSD, and their partners (San Diego Population Study, observational study). 1016 adults (aged 20-85) not on lipid medications and without known heart disease, diabetes, cancer or HIV (UCSD Statin Study, randomised trial).

MEASUREMENTS

Self-rated activity relative to others' age, 5-point Likert Scale, was evaluated by age decade, and related via correlation and regression to a suite of health-relevant subjective and objective outcomes.

RESULTS

Successively older participants reported successively greater activity relative to others of their age (greater departure from the norm for their age), p<0.001 in both studies. Relative activity significantly predicted (in regression adjusted for age) actual activity (times/week exercised), and numerous self-rated and objective health-predictors. These included general self-rated health, CES-D (depression score), sleep, tiredness, energy; body mass index, waist circumference, serum glucose, high-density lipoprotein-cholesterol, triglycerides and white cell count. Indeed, some health-predictor associations with age in participants were 'paradoxical,' consistent with greater apparent health in older age-for study participants.

CONCLUSIONS

Study participants may not be representative of the population they are intended to reflect. Our results suggest that departures from representativeness may be amplified with increasing age. Consequently, the older the age, the greater the disparity may be between what is recommended based on 'evidence, ' and what is best for the patient.

TRIAL REGISTRATION

UCSD Statin Study-Clinicaltrials.gov # NCT00330980 (http://ClinicalTrials.gov).

摘要

目的

研究参与者可能与他们所代表的目标人群有所不同。我们旨在调查年龄是否会放大这种差异，研究参与者的年龄趋势，比较他们的自评活动水平与同年龄组其他人的活动水平。

设计

在随机和观察性研究的范例中，使用参与者年龄与报告的“相对活动”（即与同年龄组其他人相比）之间的双向相关代理，来交叉检查参与者年龄与报告的“相对活动”（即与同年龄组其他人相比）之间的关系。

地点

加利福尼亚大学圣地亚哥分校（UCSD）

参与者

包括 UCSD 员工及其配偶在内的 2404 名 40-79 岁成年人（圣地亚哥人口研究，观察性研究）。1016 名未服用降脂药物且无已知心脏病、糖尿病、癌症或 HIV 的成年人（年龄 20-85 岁）（UCSD 他汀类药物研究，随机试验）。

测量方法

使用 5 分李克特量表评估自我报告的活动相对于他人年龄的相对活动，按年龄十年进行评估，并通过相关性和回归分析与一系列与健康相关的主观和客观结果相关联。

结果

在两项研究中，年龄较大的参与者报告的活动相对于同年龄组的其他人来说越来越活跃（与他们年龄的正常水平相差越大），p<0.001。相对活动显著预测（在调整年龄的回归分析中）实际活动（每周锻炼次数）以及许多自我报告和客观健康预测指标。这些包括一般自我报告的健康状况、CES-D（抑郁评分）、睡眠、疲劳、精力；体重指数、腰围、血清葡萄糖、高密度脂蛋白胆固醇、甘油三酯和白细胞计数。事实上，一些与参与者年龄相关的健康预测因素的关联是“矛盾的”，与年龄较大的人看起来更健康的情况一致。