Self administered cognitive screening test (TYM) for detection of Alzheimer’s disease: cross sectional study
BMJ 2009; 338 doi: https://doi.org/10.1136/bmj.b2030 (Published 10 June 2009) Cite this as: BMJ 2009;338:b2030
- Jeremy Brown, consultant neurologist,
- George Pengas, clinical research fellow,
- Kate Dawson, research nurse,
- Lucy A Brown, honorary research assistant,
- Philip Clatworthy, clinical research fellow
- Correspondence to: J Brown jmb75{at}medschl.cam.ac.uk
- Accepted 6 February 2009
Abstract
Objective To evaluate a cognitive test, the TYM (“test your memory”), in the detection of Alzheimer’s disease.
Design Cross sectional study.
Setting Outpatient departments in three hospitals, including a memory clinic.
Participants 540 control participants aged 18-95 and 139 patients attending a memory clinic with dementia/amnestic mild cognitive impairment.
Intervention Cognitive test designed to use minimal operator time and to be suitable for non-specialist use.
Main outcome measures Performance of normal controls on the TYM. Performance of patients with Alzheimer’s disease on the TYM compared with age matched controls. Validation of the TYM with two standard tests (the mini-mental state examination (MMSE) and the Addenbrooke’s cognitive examination-revised (ACE-R)). Sensitivity and specificity of the TYM in the detection of Alzheimer’s disease.
Results Control participants completed the TYM with an average score of 47/50. Patients with Alzheimer’s disease scored an average of 33/50. The TYM score shows excellent correlation with the two standard tests. A score of ≤42/50 had a sensitivity of 93% and specificity of 86% in the diagnosis of Alzheimer’s disease. The TYM was more sensitive in detection of Alzheimer’s disease than the mini-mental examination, detecting 93% of patients compared with 52% for the mini-mental state exxamination. The negative and positive predictive values of the TYM with the cut off of ≤42 were 99% and 42% with a prevalence of Alzheimer’s disease of 10%. Thirty one patients with non-Alzheimer dementias scored an average of 39/50.
Conclusions The TYM can be completed quickly and accurately by normal controls. It is a powerful and valid screening test for the detection of Alzheimer’s disease.
Footnotes
This work would not have been possible without the nurses and receptionists at Queen Elizabeth Hospital, King’s Lynn, North Cambridgeshire Hospital, Wisbech, and Addenbrooke’s Hospital, Cambridge, who administered the tests. We thank colleagues in the memory clinic, Cambridge, for permission to include their patients and for helpful discussions. A website is being prepared (www.tymtest.com) that will allow downloading of tests, scoring sheets, and instructions.
Contributors: JB devised and helped to design the TYM, he helped to perform and coordinated the clinical research, and wrote the first draft of the paper. GP helped in the clinical testing and in the writing of the paper and was an inter-rater tester. KD performed much of the clinical testing and scoring. PC performed the statistical analysis and prepared the figures and tables. LAB helped design the test and was an inter-rater tester. JB is guarantor.
Funding: GP was supported by Alzheimer’s Research Trust (UK) and the Cambridge Commonwealth Trust. PC was supported by the Stroke Association. The authors are independent of any funders for this work. All authors had access to all data in this study.
Competing interests: None declared.
Ethical approval: This study was performed under ethical approval from Cambridgeshire 2 research ethics committee. All participants gave informed consent.
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