Benefits of Screening Instruments for Identification of Cognitive Impairment

^{By Julie Gould}

In order to inform and update the US Preventive Services Task Force, a team of researchers sought to test the accuracy of cognitive screening instruments as well as understand both the benefits and harms of cognitive impairment treatment interventions.  

Lead by Carrie Patnode, PhD, MPH, investigator with the Kaiser Permanente Evidence-based Practice Center at the Kaiser Permanente Center for Health Research in Portland, OR, the study authors reviewed research from MEDLINE, PubMed, PsycINFO, and Cochrane Central Register of Controlled Trials. In total, Dr Patnode and colleagues reviewed 287 studies comprised of more than 280,000 older adults.  

In order to better understand what existing data lead to this review and the outcomes of the current review, Annals of Long-Term Care spoke with Dr Patnode. 

What existing data led you and your co-investigators to conduct this research? 

In 2014, the United States Preventive Services Task Force concluded that there was insufficient evidence to recommend for or against screening for cognitive impairment among older adults without signs or symptoms. That recommendation was based on a 2013 review our team did. Given the time that past, we updated the review to determine if there was additional evidence to support the Task Force’s recommendation. 

Please briefly describe your study and its findings. Were any of the outcomes particularly surprising?

We reviewed existing research on the accuracy of brief screening instruments designed to help detect mild cognitive impairment and dementia and studies on the potential benefits and harms of screening (vs. not screening) for cognitive impairment. We also reviewed studies on the effectiveness and harms of pharmacological treatments and various nonpharmacological treatments on important patient and caregiver outcomes. We found several studies that evaluated how well various screening instruments such as the MMSE, clock drawing test, and Mini-Cog can identify potential cognitive impairment. Most instruments show good sensitivity and specificity for detecting dementia. However, most instruments have only been evaluated in one or two studies. Furthermore, we only identified one study that looked at the potential benefits and harms of universally screening older adults for cognitive impairment. Given the findings in 2014, I was surprised that there were not more published studies evaluating this direct evidence. 

We identified over 200 studies that evaluated various treatments for dementia – including acetylcholinesterase inhibitors, memantine, vitamins and other medications, cognitive training, exercise, and caregiver interventions. Unfortunately, while some of these studies showed benefits for patients and caregivers in the short-term (6- to 12-months), the absolute benefit of these interventions appeared to be quite small and of unclear clinical significance.

What are the possible real-world applications of these findings in clinical practice? 

In the Task Force’s recommendation, they advise that “Clinicians should remain alert to early signs or symptoms of cognitive impairment and evaluate the individual as appropriate.” 

Do you and your co-investigators intend to expand upon this research?

We will continue to monitor the literature for updated evidence that might help answer our questions. But, have no other research plans at this time. 

Is there anything else pertaining to your research and findings that you would like to add? 

Dementia is a burdensome disease, not only to the individuals with the disease but also to their families and loved ones. Early identification of cognitive impairment could ideally help patients, their families, and their clinicians make informed decisions about their health care and important financial and legal decisions. Unfortunately, we just don’t have enough empiric evidence that answers whether the benefits outweigh the harms when considering universally screening all older adults for cognitive impairment. 

Reference:

Patnode CD, Perdue LA, Rossom RC, et al. Screening for cognitive impairment in older adults: Updated evidence report and systematic review for the us preventive services task force [published online February 25, 2020]. JAMA. 2020;323(8):764-785. doi:10.1001/jama.2019.22258