Jennifer S. Lin, MD, MCR; Elizabeth O’Connor, PhD; Rebecca C. Rossom, MD, MCR; Leslie A. Perdue, MPH; Elizabeth Eckstrom, MD, MPH
Acknowledgment: The authors thank Matthew Thompson, MD, MPH, DPhil, for his assistance with the introduction to the full evidence report; Mary Ganguli, MD, MPH, for her expert advice on MCI; Patricia G. Archbold, DNSc, RN, and Barbara J. Stewart, PhD, for their advice on caregiver interventions and outcome measures; Brittany Burda, MPH, for her assistance on data abstraction and preparation of this manuscript; Clara Soh, MPA, and Carin Olson, MD, for their assistance in data abstraction; Daphne Plaut, MLS, for creating and conducting the literature searches; Kevin Lutz, MFA, for his editorial assistance; the AHRQ staff; members of the USPSTF; and Soo Borson, MD, Katie Maslow, MSW, Riley McCarten, MD, Parminder Raina, PhD, Raj Shah, MD, Joseph Chin, MD, MS, Kurt Greenlund, PhD, and Susan Cooley, PhD, for their feedback on an early version of the evidence report.
Financial Support: This review was conducted by the Kaiser Permanente Research Affiliates Evidence-based Practice Center under contract to AHRQ, Rockville, Maryland (contract HHS-290-2007-10057-I). AHRQ staff provided oversight for the project and assisted in external review of the companion draft evidence synthesis.
Potential Conflicts of Interest: Dr. Lin: Grant (money to institution): AHRQ; Support for travel to meetings for the study or other purposes (money to institution): AHRQ; Payment for writing or reviewing the manuscript (money to institution): AHRQ; Provision of writing assistance, medicines, equipment, or administrative support (money to institution): AHRQ. Dr. O’Connor: Grant: AHRQ. Dr. Rossom: Grant: AHRQ. Ms. Perdue: Grant: AHRQ. Dr. Eckstrom: Grant: AHRQ. Disclosures can also be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=M13-1466.
Requests for Single Reprints: Reprints are available from the AHRQ Web site ( www.ahrq.gov).
This article was published online first at www.annals.org on 29 October 2013.
Current Author Addresses: Drs. Lin and O’Connor and Ms. Perdue: Kaiser Permanente Center for Health Research Northwest, 3800 North Interstate Avenue, Portland, OR 97227.
Dr. Rossom: HealthPartners, 8170 33rd Avenue South, Minneapolis, MN 55440.
Dr. Eckstrom: Oregon Health & Science University, 3181 SW Sam Jackson Parkway, Department of Medicine L475, Portland, OR 97239.
Author Contributions: Conception and design: J.S. Lin, E. Eckstrom.
Analysis and interpretation of the data: J.S. Lin, E. O’Connor, R.C. Rossom, L.A. Perdue, E. Eckstrom.
Drafting of the article: J.S. Lin, E. O’Connor, R.C. Rossom.
Critical revision of the article for important intellectual content: J.S. Lin, E. O’Connor, R.C. Rossom, E. Eckstrom.
Final approval of the article: J.S. Lin, E. O’Connor, R.C. Rossom, L.A. Perdue, E. Eckstrom.
Statistical expertise: E. O’Connor.
Administrative, technical, or logistic support: L.A. Perdue.
Collection and assembly of data: J.S. Lin, E. O’Connor, R.C. Rossom, L.A. Perdue, E. Eckstrom.
This article has been corrected. The original version (PDF) is appended to this article as a supplement.
Earlier identification of cognitive impairment may reduce patient and caregiver morbidity.
To systematically review the diagnostic accuracy of brief cognitive screening instruments and the benefits and harms of pharmacologic and nonpharmacologic interventions for early cognitive impairment.
MEDLINE, PsycINFO, and the Cochrane Central Register of Controlled Trials through December 2012; systematic reviews; clinical trial registries; and experts.
English-language studies of fair to good quality, primary care–feasible screening instruments, and treatments aimed at persons with mild cognitive impairment or mild to moderate dementia.
Dual quality assessment and abstraction of relevant study details.
The Mini-Mental State Examination (k = 25) is the most thoroughly studied instrument but is not available for use without cost. Publicly available instruments with adequate test performance to detect dementia include the Clock Drawing Test (k = 7), Mini-Cog (k = 4), Memory Impairment Screen (k = 5), Abbreviated Mental Test (k = 4), Short Portable Mental Status Questionnaire (k = 4), Free and Cued Selective Reminding Test (k = 2), 7-Minute Screen (k = 2), and Informant Questionnaire on Cognitive Decline in the Elderly (k = 5). Medications approved by the U.S. Food and Drug Administration for Alzheimer disease (k = 58) and caregiver interventions (k = 59) show a small benefit of uncertain clinical importance for patients and their caregivers. Small benefits are also limited by common adverse effects of acetylcholinesterase inhibitors and limited availability of complex caregiver interventions. Although promising, cognitive stimulation (k = 6) and exercise (k = 10) have limited evidence to support their use in persons with mild to moderate dementia or mild cognitive impairment.
Limited studies in persons with dementia other than Alzheimer disease and sparse reporting of important health outcomes.
Brief instruments to screen for cognitive impairment can adequately detect dementia, but there is no empirical evidence that screening improves decision making. Whether interventions for patients or their caregivers have a clinically significant effect in persons with earlier detected cognitive impairment is still unclear.
Agency for Healthcare Research and Quality.
Summary of evidence search and selection.
SER = systematic evidence review.
Appendix Table 1. Inclusion Criteria
Appendix Table 2. Diagnostic Accuracy of Brief Cognitive Screening Instruments in Primary Care for Dementia
Appendix Table 3. Benefits and Harms of Interventions for Mild to Moderate Dementia and MCI
Meta-analyses of effects of AChEIs and memantine on global cognitive function, measured by the ADAS-cog.
Weights are from random-effects analysis. AChEI = acetylcholinesterase inhibitor; AD = Alzheimer disease; ADAS-cog = Alzheimer's Disease Assessment Scale-Cognitive Subscale; MCI = mild cognitive impairment; MMSE = Mini-Mental State Examination; VaD = vascular dementia.
* Included in the systematic review by Raina and colleagues, 2008 (14).
Meta-analyses of effects of AChEIs and memantine on withdrawals due to adverse events.
Weights are from random-effects analysis. AChEI = acetylcholinesterase inhibitor; RR = relative risk.
Meta-analyses of effects of psychoeducational caregiver interventions on caregiver burden.
Weights are from random-effects analysis. REACH = Resources for Enhancing Alzheimer's Caregiver Health.
Meta-analyses of effects of psychoeducational caregiver interventions on caregiver depression.
Rónán O'Caoimh, William Molloy
Centre for Gerontology and Rehabilitation, University College Cork, St Finbarrs Hospital, Cork City, Ireland
November 20, 2013
Cognitive Screening in Primary Care: Key Questions.
To the Editor: We read with interest Lin et al‘’s (1) review on behalf of the U.S Preventative Services Task Force. This important and timely systematic review clearly summarizes the current evidence base for cognitive screening, a topical and controversial issue at present (2),(3). While thorough and balanced, there are a number of wider issues that merit discussion. The authors investigated five key questions. We propose an additional five, suggested by this review, that require clarification and should direct future research in this area. These are the what, why, who, when, and where of cognitive screening?
Firstly, what type of cognitive screening is required? The papers included in this review predominantly investigated the performance of cognitive screening tests in unselected community-dwelling older adults in primary care, the ethical and clinical benefits of which remain uncertain (1),(2). Comparison of targeted versus non-targeted screening should therefore be investigated in future.
Secondly, why screen? The authors rightly point out that there is a lack of empirical evidence supporting expert consensus guidelines that extoll the benefits of early detection. Although screening for cognitive impairment doesn’t yet meet Wilson’s Criteria, unlike screening for other conditions, its major benefits lie in health promotion (“planning for the future”). This is difficult to measure and may explain the paucity of evidence to date.
Thirdly who should be screened? In addition to screening symptomatic patients, the effects of targeting high-risk groups with the right cognitive screen, for example those with Parkinson’s disease, should be examined . The authors rightly highlight this and the lack of cut-off scores as factors limiting the utility of screening. The effect of developing and validating these among large populations of patients with different dementia subtypes is also required.
Fourthly, when should cognitive screening take place? Cognitive impairment is a heterogeneous disorder and presents in a heterogeneous fashion. In this sense one single screening policy is unlikely to be successful. We agree with the authors that research comparing triggers for screening in primary care is required and suggest that future research should compare opportunistic screening with targeted approaches.
Finally, where should screening take place? Although there is a paucity of evidence for screening in primary care, research from memory clinics suggests that primary care offers superior post-diagnostic management (4), indicating that future reviews should compare screening in primary and secondary care settings.
We agree with the authors that the evidence that screening improves decision making in primary care is lacking but argue that this should not deter the screening of symptomatic patients. We suggest that these additional five questions highlight the future direction of research and subsequent systematic reviews into cognitive screening.
1. Lin JS, O'Connor E, Rossom RC, Leslie A. Perdue LA, Eckstrom E. Screening for Cognitive Impairment in Older Adults: A Systematic Review for the U.S. Preventive Services Task Force. Ann Intern Med. Published online 22 October 2013 doi:10.7326/0003-4819-159-9-201311050-00730.
2. Boustani M. Dementia Screening in Primary Care: Not Too Fast! Journal of the American Geriatrics Society 2013, 61: 1205–1207.
3. McCarten JR. The case for screening for cognitive impairment in older adults. J Am Geriatr Soc. 2013 Jul;61(7):1203-5. doi: 10.1111/jgs.12319_1. Epub 2013 Jun 19.
4. Meeuwsen EJ, Melis RJ, Van Der Aa GC, Golüke-Willemse GA, De Leest BJ, Van Raak FH, Schölzel-Dorenbos CJ, Verheijen DC, Verhey FR, Visser MC, Wolfs CA, Adang EM, Olde Rikkert MG. Effectiveness of dementia follow-up care by memory clinics or general practitioners: randomised controlled trial. BMJ 2012 May 15;344:e3086. doi: 10.1136/bmj.e3086.
Ronald Somers, PhD
Government of South Australia
December 13, 2013
No Benefit from Screening for Cognitive Impairment?
TO THE EDITOR: I read the research report by J.S. Lin et al (1) with considerable interest and some disappointment in the authors’ conclusion. Readers were informed that `Although it is clear that brief instruments to screen for cognitive impairment can adequately detect dementia, there is no empirical evidence that screening for or early diagnosis of cognitive impairment improves decision-making or important patient, caregiver, or societal outcomes.’ There exists a clear example which runs counter to this sweeping negative conclusion. It appears that the authors did not consider the successful use of cognitive screening in the certification of driving licences. Cognitive screening is applied as part of the more general assessment of medical fitness to drive. Historically, such screening has relied on diagnostic tools that were not specifically validated for driving ability. Increasingly however, instruments have been developed which predict on-road ability (2). Readers may agree that identifying drivers who are a danger to themselves and others, and keeping them off the road, is a fairly significant patient and societal outcome.
Ronald L Somers, PhD
University of Adelaide
Potential Conflicts of Interest: None
1. Lin JS, O’Connor E, Rossom RC, Perdue LA, Eckstrom E. Screening for cognitive impairment in older adults: a systematic review for the US Preventive Services Task Force. Ann Intern Med. 2013;159:601-12.
2. Carr DB, Barco PP, Wallendorf MJ, Snellgrove CA, Ott BR. Predicting road test performance in drivers with dementia. J Am Geriatr Soc. 2011 Nov;59(11):2112-7.
Lin JS, O’Connor E, Rossom RC, et al. Screening for Cognitive Impairment in Older Adults: A Systematic Review for the U.S. Preventive Services Task Force. Ann Intern Med. 2013;159:601–612. doi: https://doi.org/10.7326/0003-4819-159-9-201311050-00730
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Published: Ann Intern Med. 2013;159(9):601-612.
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