Manjer J, Carlsson S, Elmståhl S, Gullberg B, Janzon L, Lindström M, Mattisson I, Berglund G
Department of Community Medicine, Lund University, Malmö University Hospital, Sweden.
Eur J Cancer Prev. 2001 Dec;10(6):489-99. doi: 10.1097/00008469-200112000-00003.
In order to investigate potential selection bias in population-based cohort studies, participants (n = 28098) and non-participants (n = 40807) in the Malmö Diet and Cancer Study (MDCS) were compared with regard to cancer incidence and mortality. MDCS participants were also compared with participants in a mailed health survey with regard to subjective health, socio-demographic characteristics and lifestyle. Cancer incidence prior to recruitment was lower in non-participants, Cox proportional hazards analysis yielded a relative risk (RR) with a 95% confidence interval of 0.95 (0.90-1.00), compared with participants. During recruitment, cancer incidence was higher in non-participants, RR: 1.08 (1.01-1.17). Mortality was higher in non-participants both during, 3.55 (3.13-4.03), and following the recruitment period, 2.21 (2.03-2.41). The proportion reporting good health was higher in the MDCS than in the mailed health survey (where 74.6% participated), but the socio-demographic structure was similar. We conclude that mortality is higher in non-participants than in participants during recruitment and follow-up. It is also suggested that non-participants may have a lower cancer incidence prior to recruitment but a higher incidence during the recruitment period.
为了调查基于人群的队列研究中潜在的选择偏倚，我们比较了马尔默饮食与癌症研究（MDCS）中的参与者（n = 28098）和非参与者（n = 40807）的癌症发病率和死亡率。还将MDCS参与者与邮寄健康调查的参与者在主观健康、社会人口学特征和生活方式方面进行了比较。招募前非参与者的癌症发病率较低，与参与者相比，Cox比例风险分析得出相对风险（RR）为0.95（95%置信区间为0.90 - 1.00）。在招募期间，非参与者的癌症发病率较高，RR为1.08（1.01 - 1.17）。非参与者在招募期间的死亡率较高，为3.55（3.13 - 4.03），在招募期之后的死亡率也较高，为2.21（2.03 - 2.41）。报告健康状况良好的比例在MDCS中高于邮寄健康调查（后者的参与率为74.6%），但社会人口学结构相似。我们得出结论，在招募和随访期间，非参与者的死亡率高于参与者。还表明，非参与者在招募前可能癌症发病率较低，但在招募期间发病率较高。
