Evaluating the real-world representativeness of participants with mild cognitive impairment in Canadian research protocols: a comparison of the characteristics of a memory clinic patients and research samples

  • Vivian Huang Ryerson University http://orcid.org/0000-0001-7232-124X
  • David B. Hogan University of CalgaryHotchkiss Brain Institute
  • Zahinoor Ismail University of Calgary, University of Waterloo
  • Colleen J. Maxwell University of Waterloo, Hotchkiss Brain Institute
  • Eric E. Smith University of CalgaryHotchkiss Brain Institute
  • Brandy L. Callahan University of CalgaryHotchkiss Brain InstituteMathison Centre for Mental Health Research & Education
Keywords: mild cognitive impairment, exclusion criteria, generalizability

Abstract

Background

Studies of mild cognitive impairment (MCI) employ rigor­ous eligibility criteria, resulting in sampling that may not be representative of the broader clinical population.

Objective

To compare the characteristics of MCI patients in a Calgary memory clinic to those of MCI participants in published Canadian studies.

Methods

Clinic participants included 555 MCI patients from the PROspective Registry of Persons with Memory SyMPToms (PROMPT) registry in Calgary. Research participants in­cluded 4,981 individuals with MCI pooled from a systematic literature review of 112 original, English-language peer-reviewed Canadian studies. Both samples were compared on baseline sociodemographic variables, medical and psychiatric comorbidities, and cognitive performance for MCI due to Alzheimer’s disease and Parkinson’s disease.

Results

Overall, clinic patients tended to be younger, more often male, and more educated than research participants. Psychiatric dis­orders, traumatic brain injury, and sensory impairment were commonplace in PROMPT (up to 83% affected) but > 80% studies in the systematic review excluded these conditions. PROMPT patients also performed worse on global cognition measures than did research participants.

Conclusion

Stringent eligibility criteria in Canadian research studies ex­cluded a considerable subset of MCI patients with comorbid medical or psychiatric conditions. This exclusion may con­tribute to differences in cognitive performance and outcomes compared to real-world clinical samples.

Author Biographies

Vivian Huang, Ryerson University

Department of Psychology

David B. Hogan, University of CalgaryHotchkiss Brain Institute

Cumming School of Medicine

 

Zahinoor Ismail, University of Calgary, University of Waterloo

Cumming School of Medicine, Hotchkiss Brain Institute, Mathison Centre for Mental Health Research & Education, Schools of Pharmacy and Public Health & Health Systems, Department of Psychology

Colleen J. Maxwell, University of Waterloo, Hotchkiss Brain Institute

Hotchkiss Brain Institute, Schools of Pharmacy and Public Health & Health Systems

Eric E. Smith, University of CalgaryHotchkiss Brain Institute

Cumming School of Medicine

 

Brandy L. Callahan, University of CalgaryHotchkiss Brain InstituteMathison Centre for Mental Health Research & Education

Department of Psychology

Published
2020-11-23
How to Cite
Huang, V., Hogan, D. B., Ismail, Z., Maxwell, C. J., Smith, E. E., & Callahan, B. L. (2020). Evaluating the real-world representativeness of participants with mild cognitive impairment in Canadian research protocols: a comparison of the characteristics of a memory clinic patients and research samples. Canadian Geriatrics Journal, 23(4), 297-328. https://doi.org/10.5770/cgj.23.416
Section
Original Research