METHODS: The source population included 17 936 individuals invited to the Copenhagen Aging and Midlife Biobank during 2009-11 (ages 49-63 years). Participants counted 7185 (40.1%). Register data were obtained for every invited person from 7 years before invitation to the end of 2020. The association between education and mortality was estimated using Cox regression models among participants, IPW participants and the source population.
RESULTS: Participants had higher socioeconomic position and fewer hospital contacts before baseline than the source population. Frequency measures of participants approached those of the source population after IPW. Compared with primary/lower secondary education, upper secondary, short tertiary, bachelor and master/doctoral were associated with reduced risk of death among participants (adjusted hazard ratio [95% CI]: 0.60 [0.46; 0.77], 0.68 [0.42; 1.11], 0.37 [0.25; 0.54], 0.28 [0.18; 0.46], respectively). IPW changed the estimates marginally (0.59 [0.45; 0.77], 0.57 [0.34; 0.93], 0.34 [0.23; 0.50], 0.24 [0.15; 0.39]) but not only towards those of the source population (0.57 [0.51; 0.64], 0.43 [0.32; 0.60], 0.38 [0.32; 0.47], 0.22 [0.16; 0.29]).
CONCLUSIONS: Frequency measures of study participants may not reflect the source population in the presence of self-selection, but the impact on association measures can be limited. IPW may be useful for (self-)selection bias correction, but the returned results can still reflect residual or other biases and random errors.
方法:来源人群包括2009-11年间邀请到哥本哈根老龄化和中年生物样本库的17936人(年龄49-63岁)。参与者计数7185(40.1%)。从邀请前7年到2020年底,获得了每个受邀人的注册数据。使用Cox回归模型估计参与者之间的教育和死亡率之间的关联,IPW参与者和来源人群。
结果:受试者在基线前的社会经济地位较高,医院接触者较少。IPW后参与者的频率测量接近源人群的频率测量。与小学/初中教育相比,高中,短三级,学士和硕士/博士与参与者死亡风险降低相关(调整后风险比[95%CI]:0.60[0.46;0.77],0.68[0.42;1.11],0.37[0.25;0.54],0.28[0.18;0.46],分别)。IPW略微改变了估计值(0.59[0.45;0.77],0.57[0.34;0.93],0.34[0.23;0.50],0.24[0.15;0.39]),但不仅针对源人群的人群(0.57[0.51;0.64],0.43[0.32;0.60],0.38[0.32;0.47],0.22[0.16;0.29])。
结论:研究参与者的频率测量可能无法反映存在自我选择的来源人群,但对关联措施的影响可能是有限的。IPW可用于(自)选择偏差校正,但是返回的结果仍然可以反映残差或其他偏差和随机误差。