Cognitive Impairment—Clinician Summary

POPULATION

This recommendation applies to community dwelling older adults (≥65 years of age) who do not have noticeable symptoms suggestive of mild cognitive impairment or dementia. This recommendation does not apply to men or women who are concerned about their own cognitive performance (i.e. the patient has raised complaints about cognitive changes with their clinician or others) or who are suspected of having mild cognitive impairment or dementia by clinicians or non-clinicians (caregivers, family, or friends) and/or have symptoms suggestive of mild cognitive impairment or dementia (such as loss of memory, language, attention, visuospatial, or executive functioning, or behavioural or psychological symptoms that may either mildly or significantly impact a patient’s day-to-day life or usual activities).

BURDEN OF ILLNESS

The incidence of dementia in Canadian adults aged 65 to 79 years is 43 per 1000 persons and rises with age (to 212 per 1000 in Canadians aged 85 and older). Reported prevalence of mild cognitive impairment vary due to several factors such as the diagnostic test score (i.e. cutoff) used to define mild cognitive impairment, age at the initial assessment, and length of follow-up. Published Canadian cohort prevalence rates for mild cognitive impairment are not available. Studies from the United States have reported prevalence for mild cognitive impairment ranging from 9.9% to 35.2% for adults aged 70 or older.

INTERVENTIONS

• Interventions screening for cognitive impairment.
• Interventions (behavioral and pharmacological) treating mild cognitive impairment (MCI).

Note: If screening for cognitive impairment were to be conducted in the asymptomatic general population, most cases detected would likely be MCI – not dementia. Therefore, the CTFPHC felt it was important to examine the effectiveness of treatment on MCI.

RECOMMENDATIONS

We recommend not screening asymptomatic adults (≥65 years of age) for cognitive impairment Strong recommendation, low quality evidence

BASIS OF RECOMMENDATIONS

• No randomized trials have evaluated the benefits of screening for cognitive impairment.
• Available data suggest that pharmacological treatments are not effective in people with mild cognitive impairment, and that non-pharmacological therapies (i.e. exercise, cognitive training, and rehabilitation) produce only small benefits, which do not appear to be clinically significant.
• Existing studies suggest that approximately one in ten people without cognitive impairment may erroneously screen positive for mild cognitive impairment using the Mini Mental State Examination (MMSE) and that one in four people may incorrectly be classified as positive using the Montreal Cognitive Assessment tool (MoCA).

DETAILS OF RECOMMENDED SERVICES

• While we recommend against screening for cognitive impairment, practitioners should examine and assess cognitive functions and functional autonomy whenever a patient presents with signs and symptoms of impairment or when family members or patients express concerns about potential cognitive decline.

CONSIDERATIONS FOR IMPLEMENTATION

• It is difficult to establish the potential value of screening in older populations, such as in people that are over 85 years of age. The prevalence of MCI and dementia increases in older groups of the population (e.g. >85). However, considering that lack of high quality evidence demonstrating that treatment is effective and the potential for high false positive rates that may result from screening across all age groups, the CTFPHC considers it is not appropriate to recommend population screening in any age group over 65 years of age. Instead, the CTFPHC acknowledges the importance of clinical evaluation or case-finding in the context of signs and symptoms to ensure patients are attended to and treated individually.