SAGE: A short test for detecting Alzheimer's?

Contributed by: Dennis Fortier, President, Medical Care Corporation
The Self-Administered Gerocognitive Examination (SAGE) has received a fair amount of attention this year. Most of the attention has been driven by PR efforts and a website hosted by The Ohio State University where the test was developed.

Unfortunately, much of the press coverage has been somewhat sloppy and perhaps misleading. While the scientists who developed SAGE described it as "a test to measure thinking abilities", the press has repeatedly characterized it as an Alzheimer's test. As readers of this blog know, dozens of medical conditions can impair memory and other thinking abilities, Alzheimer's disease is merely one of them.

Press mis-characterizations aside, the data supporting the validity of the SAGE is quite minimal.  The instrument, a 15-minute self-administered questionnaire, was developed based on responses from a small sample of 63 subjects, and then validated on a sample of 1,047 subjects.

The website and support materials for the SAGE suggest that the instrument can detect dementia with fairly high accuracy of 95%. This has been the root claim for much of the ensuing press coverage. Remember though, the definition of dementia includes "impairment severe enough to interfere with social and occupational function". In this regard, a test that can detect such severe impairment may have little value, especially if it cannot detect more subtle symptoms such as those we see in the earliest stages of Alzheimer's disease.

From a clinical point of view, it is much more important to detect subtle stages of decline called Mild Cognitive Impairment (MCI). MCI is caused by a great many medical conditions and is often confused with normal, age-related changes in cognition. In fact, incorrectly assuming that subtle changes are caused by normal aging, rather than by an emerging medical condition, is the primary foe in our efforts to intervene at early stages against the various conditions that impair memory. Distinguishing the two is key to proactive management of cognitive health. According to the instrument's website, the SAGE is 62% sensitive for detecting MCI, which will provide little help for physicians trying to distinguish MCI from normal aging.

Other well-validated instruments are more useful in detecting MCI.  The most accurate test in the published literature is the MCI Screen.  It is 97% accurate in distinguishing MCI from normal aging, but it is not self-administered. Rather, it is generally administered by medical staff or a researcher. The ideal would be an instrument with the self-administering ease of the SAGE and the accuracy of the MCI Screen.

Is the Risk for Alzheimer's Disease Declining?

Contributed by: Dennis Fortier, President, Medical Care Corporation
Stop the press! Is this good news about Alzheimer's Disease? It depends on how you look at it.

A recent perspective article*, published in the New England Journal of Medicine, cites several studies supporting the notion that the risk of having Alzheimer's disease is declining. The article notes that the probability of a person of a given age, having any form of dementia today, is lower than it was a few decades ago. That sounds positive.

Despite the tempting headline of "Declining Risk", such a trend is most likely driven by overall improvements in population health. Today's seniors are unquestionably wealthier and better educated than those of the past, they smoke less, have fewer strokes, have better managed cholesterol, and have lower blood pressure. All of those factors affect risk of Alzheimer's disease and other causes of dementia.

Also, while risk at a given age may be declining, the number of people reaching old age (and even very old age) is sharply climbing. Prevalence at a given age may be lower, but incidence at older ages is clearly rising.

There is no reason to believe that the risk of Alzheimer's disease is magically declining. There is much hope, however, that awareness about risk factors and the importance of managing them, is helping us to forestall the ravages of dementing illnesses, and buying time for the nation's R&D efforts to find better treatments.

So keep exercising, eating right, using your brains, and managing your chronic conditions.  For now, that is your best strategy for keeping your brain healthy for the longest time.

n engl j med, 369;24,, december 122013

Screening for Cognitive Impairment

Contributed by: Dennis Fortier, President, Medical Care Corporation

Yesterday, the U.S. Preventative Services Task Force (USPSTF) ruled that there is insufficient evidence to make a recommendation, either for or against, routine screening for cognitive impairment in older adults. Today, the press is ablaze with sloppy reporting on the matter.

Many news stories (like this from US News and World Report) are conflating cognitive impairment with dementia, but readers of this blog understand that cognitive impairment may be very mild whereas dementia is, by definition  a severe loss of cognitive capacity. Many others (like this from Time), are interchanging dementia and Alzheimer's disease, which inappropriately implies that the two are one in the same, and obscures the fact that Alzheimer's is but one of the many causes of dementia.

To be clear, the USPSTF did not rule against anything. They merely concluded that the evidence is not strong enough to make a recommendation one way or the other. More importantly, their ruling was related to "screening" of "older adults" for "cognitive impairment". In other words, should the healthcare system invest in regular cognitive assessment of all older adults, whether they suspect a problem or not? Their conclusion? They're not sure.  They're not for it and not against it.

Rather, the public should monitor their cognitive health vigilantly and promptly report concerns to their physicians for a thorough evaluation. This will allow early intervention against treatable problems like thyroid dysfunction, vitamin deficiency, anxiety/depression, sleep disorders, and out of control diabetes, all known contributors to cognitive deficits. It will also facilitate early diagnosis of Alzheimer's disease.

This is important because Alzheimer's can be effectively managed for a significant percentage of patients. Effective management of Alzheimer's includes early diagnosis, physical exercise, proper diet, strict control of hypertension and diabetes, poly-therapy with a cholinesterase inhibitor and Namenda, ongoing social and intellectual stimulation, and caregiver education. All of these interventions have been shown to promote optimal disease management and, when brought together as a robust therapeutic regimen, can be surprisingly effective.