Dementia, including Alzheimer's disease, is a growing problem worldwide. Prevention or early detection of the disease or a prodromal cognitive decline is necessary. By means of our long-term follow-up ‘Vogel study’, we aim to predict the pathological cognitive decline of a German cohort (mean age was 73.9 ± 1.55 years at first visit) with three measurement time points within 6 years per participant. Especially in samples of the elderly and subjects with chronic or co-morbid diseases, dropouts are one of the biggest problems of long-term studies. In contrast to the large number of research articles conducted on the course of dementia, little research has been done on the completion of treatment. To ensure unbiased and reliable predictors of cognitive decline from study completers, our objective was to determine predictors of dropout. We conducted multivariate analyses of covariance and multinomial logistic regression analyses to compare and predict the subject's dropout behaviour at the second visit 3 years after baseline (full participation, partial participation and no participation/dropout) with neuropsychiatric, cognitive, blood and lifestyle variables. Lower performance in declarative memory, attention and visual–spatial processing predicted dropout rather than full participation. Lower performance in visual–spatial processing predicted partial participation as opposed to full participation. Furthermore, lower performance in mini-mental status examination predicted whether subjects dropped out or participated partially instead of full participation. Baseline cognitive parameters are associated with dropouts at follow-up with a loss of impaired participants. We expect a bias into a healthier sample over time.

中文翻译：

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认知衰退纵向 Vogel 研究中与辍学相关的因素

痴呆症，包括阿尔茨海默氏病，是世界范围内日益严重的问题。预防或早期发现疾病或前驱认知能力下降是必要的。通过我们的长期随访“Vogel 研究”，我们的目标是通过每位参与者 6 年内的三个测量时间点来预测德国队列（首次就诊时平均年龄为 73.9 ± 1.55 岁）的病理性认知衰退。特别是在老年人和患有慢性或合并症的受试者样本中，辍学是长期研究的最大问题之一。与针对痴呆病程进行的大量研究文章相比，对完成治疗的研究很少。为确保研究完成者对认知能力下降的预测指标无偏见且可靠，我们的目标是确定辍学的预测指标。我们进行了多变量协方差分析和多项逻辑回归分析，以比较和预测受试者在基线后 3 年第二次就诊时的辍学行为（完全参与、部分参与和不参与/辍学）与神经精神、认知、血液和生活方式变量。陈述性记忆、注意力和视觉空间处理方面的较低表现预示着辍学而不是完全参与。视觉空间处理的较低表现预示着部分参与而不是完全参与。此外，迷你精神状态检查的较低表现预测了受试者是否辍学或部分参与而不是全部参与。基线认知参数与随访中因受损参与者流失而退出有关。