General cognitive ability assessment in the German National Cohort (NAKO) – The block-adaptive number series task

Abstract

Objectives. Evaluate the block-adaptive number series task of reasoning, as a time-efficient proxy of general cognitive ability in the Level-2 sample of the German National Cohort (NAKO), a population-based mega cohort.

Methods. The number series task consisted of two blocks of three items each, administered as part of the touchscreen-based assessment. Based on performance on the first three items, a second block of appropriate difficulty was automatically administered. Scoring of performance was based on the Rasch model. Relations of performance scores to age, sex, education, study centre, language proficiency, and scores on other cognitive tasks were examined.

Results. Except for one very difficult item, the data of the remaining 14 items showed sufficient fit to the Rasch model (Infit: 0.89–1.04; Outfit: 0.80–1.08). The resulting performance scores (N = 21,056) had a distribution that was truncated at very high levels of ability. The reliability of the performance estimates was satisfactory. Relations to age, sex, education, and the executive function factor of the other cognitive tasks in the NAKO supported the validity.

Conclusions. The number series task provides a valid proxy of general cognitive ability for the Level-2 sample of the NAKO, based on a highly time-efficient assessment procedure.

Keywords:

• Reasoning
• Rasch model
• cognitive ageing
• education
• German National Cohort

NAKO Investigators (Study Centre, Name, Affiliation)

Table

¹Institute of Epidemiology, Helmholtz Centre Munich, German Research Centre for Environmental Health, Neuherberg, Germany ([email protected])

²Department of Epidemiology, Institute for Medical Information Processing, Biometry and Epidemiology, Medical Faculty, Ludwig-Maximilians-Universität München, Munich, Germany ([email protected])

³Department of Epidemiology and Preventive Medicine, University of Regensburg, Regensburg, Germany ([email protected], [email protected])

⁴Division of Cancer Epidemiology, German Cancer Research Centre (DKFZ), Heidelberg, Germany ([email protected])

⁵Network Ageing Research, Heidelberg University, Heidelberg, Germany ([email protected])

⁶Division of Clinical Epidemiology and Ageing Research, German Cancer Research Centre (DKFZ), Heidelberg, Germany ([email protected])

⁷Institute for Prevention and Cancer Epidemiology, Faculty of Medicine and Medical Centre, University of Freiburg, Freiburg, Germany ([email protected])

⁸Institute of Medical Informatics, Biometry and Epidemiology (IMIBE), University of Duisburg-Essen, University Hospital Essen, Essen, Germany ([email protected], [email protected])

⁹Institute for Epidemiology and Social Medicine, University of Münster, Münster, Germany ([email protected], [email protected])

¹⁰Molecular Epidemiology Research Group, Max Delbrück Centre for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany ([email protected], [email protected])

¹¹Charité – University Medical Centre Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Berlin, Germany ([email protected])

¹²MDC/BIH Biobank, Max Delbrück Centre for Molecular Medicine in the Helmholtz Association (MDC), and Berlin Institute of Health (BIH), Berlin, Germany ([email protected])

¹³Institute for Social Medicine, Epidemiology, and Health Economics, Charité –University Medical Centre Berlin, Berlin, Germany ([email protected], [email protected])

¹⁴Department of Molecular Epidemiology, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany ([email protected])

¹⁵Institute of Nutritional Science, University of Potsdam, Potsdam, Germany ([email protected])

¹⁶Department for Epidemiology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany ([email protected], [email protected])

¹⁷PhD Programme ‘Epidemiology’, Braunschweig-Hannover, Germany ([email protected])

¹⁸Institute for Medical Biometry and Epidemiology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany ([email protected], [email protected])

¹⁹Leibniz Institute for Prevention Research and Epidemiology (BIPS), Bremen, Germany ([email protected], [email protected])

²⁰Institute of Epidemiology, Kiel University, Kiel, Germany ([email protected])

²¹Institute for Community Medicine, Section Clinical-Epidemiological Research, University Medicine Greifswald (UMG), Greifswald, Germany ([email protected])

²²Institute for Community Medicine, Section Epidemiology of Health Care and Community Health, University Medicine Greifswald (UMG), Greifswald, Germany ([email protected])

²³German Centre for Neurodegenerative Diseases (DZNE) Site Rostock/Greifswald, Germany ([email protected])

Acknowledgments

We thank all study participants and staff at the NAKO study centres, the data management and integration centre, and the NAKO head office who enabled the conduction of the study and made the collection of all data possible.

Statement of interest

H. J. Grabe has received travel grants and speakers honoraria from Fresenius Medical Care, Neuraxpharm, Servier, and Janssen Cilag as well as research funding from Fresenius Medical Care.

Wolfgang Hoffmann received lecture fees and/or travel support from Roche, AMGEN, Pfizer, and a royalty from Janssen-Cilag.

Additional information

Funding

The German National Cohort (www.nako.de) is funded by the Federal Ministry of Education and Research [project numbers: 01ER1301A/B/C and 01ER1511D], the federal states, and the Helmholtz Association, with additional financial support from the participating universities and the participating institutes of the Leibniz Association and the Helmholtz Association. This work was supported by the German Federal Ministry of Education and Research (BMBF) through ERA-NET NEURON, ‘SynSchiz – Linking synaptic dysfunction to disease mechanisms in schizophrenia’ – a multilevel investigation ‘[01EW1810 to MR]’, through ERA-NET NEURON ‘Impact of Early life MetaBolic and psychosocial strEss on susceptibility to mental Disorders; from converging epigenetic signatures to novel targets for therapeutic intervention’ [01EW1904 to M. Rietschel].