Department of Medicine, Clinical Epidemiology Unit, Karolinska Institutet, T2 Eugeniahemmet, Karolinska University Hospital, Solna, 17176, Stockholm, Sweden.
Eur J Epidemiol. 2012 Mar;27(3):153-62. doi: 10.1007/s10654-011-9630-1. Epub 2011 Nov 17.
Bias due to non-response in observational studies may lead to false risk estimates. We evaluated potential selective non-response in Stockholm Diabetes Prevention Program (SDPP) using a population-based drug register. A cohort of 12,952 men and 19,416 women, aged 35-56 years, was screened for diabetes and family history of diabetes (FHD). Response rate: 79% in men and 85% in women. Of the 4,209 men and 6,916 women that were invited, 70 and 68% participated in a baseline health examination including oral glucose tolerance test. A follow-up was performed in 79% of male and 70% of female baseline participants. We used data from the prescription register to estimate absolute risks and ORs for drug-treated diabetes in the non-response/non-participation groups. At both screening and baseline steps absolute risks of drug-treated diabetes were equal in non-participants and participants. Adjusted ORs were 0.9-1.0. At follow-up, absolute risks were higher among non-participants than participants, men 6.2/4.4% and women 2.6/1.6%, adjusted ORs 1.4 (0.9-2.3) and 1.5 (0.9-2.4), suggesting selective non-participation. Further analyses of FHD, smoking, physical activity, socioeconomic position and psychological distress demonstrated no previous false risk estimates for type 2 diabetes. However, for body mass index, there were indications of overestimation in women. We conclude that bias from non-response was not present at screening or baseline steps, suggesting that diabetes prevalence and risks may be estimated from a population-based cohort study with high attendance rate such as the SDPP. However, follow-up data should be treated with some caution, since the sample may have become biased.
在观察性研究中，由于无应答导致的偏倚可能会导致错误的风险估计。我们使用基于人群的药物登记处评估了斯德哥尔摩糖尿病预防计划（SDPP）中潜在的选择性无应答。一个由 12952 名男性和 19416 名女性组成的队列，年龄在 35-56 岁之间，接受了糖尿病和家族糖尿病史（FHD）的筛查。应答率：男性为 79%，女性为 85%。在受邀的 4209 名男性和 6916 名女性中，有 70%和 68%参加了包括口服葡萄糖耐量试验在内的基线健康检查。对 79%的男性和 70%的女性基线参与者进行了随访。我们使用处方登记处的数据来估计未应答/未参与者组中药物治疗糖尿病的绝对风险和比值比（OR）。在筛查和基线阶段，未参与者和参与者的药物治疗糖尿病的绝对风险相等。调整后的 OR 为 0.9-1.0。在随访时，未参与者的绝对风险高于参与者，男性为 6.2/4.4%，女性为 2.6/1.6%，调整后的 OR 分别为 1.4（0.9-2.3）和 1.5（0.9-2.4），表明选择性不参与。对 FHD、吸烟、身体活动、社会经济地位和心理困扰的进一步分析表明，2 型糖尿病的风险估计没有以前的错误。然而，对于体重指数，女性存在高估的迹象。我们的结论是，在筛查或基线阶段不存在无应答偏倚，这表明，如 SDPP 这样的高参与率的基于人群的队列研究可以估计糖尿病的患病率和风险。然而，应该谨慎对待随访数据，因为样本可能已经存在偏差。
