Should primary care providers screen the aging general population for dementia, just like they do for many other diseases? One argument against this coming prospect is that there isn't much doctors can do for people who test positive—or is there? Last month in New York City, a group of dementia health care experts met to discuss whether knowing if someone has dementia helps doctors provide better overall medical care. Some evidence says yes, but identifying people with dementia is challenging in the current health care system.
To Screen Or Not to Screen? It’s an Urgent Question
Howard Fillit of the New York City-based Alzheimer’s Drug Discovery Foundation (ADDF) once visited a medical practice about 50 miles from Tampa, Florida. He was intrigued that the physician running the practice saw some 17,000 patients a year, half of whom were on Medicare, the federal health insurance program for Americans 65 and older. Yet none of the patients had been prescribed cholinesterase inhibitors, the standard treatment for Alzheimer’s disease (AD). So Fillit said to the Florida physician, “You have 8,000 to 9,000 people on Medicare. If you look at the statistics, you should have 800 to 900 people with dementia.” The physician responded, “Well, doc, we just don’t see it down here.”
Fillit shared the anecdote at the Dementia Screening and Detection Meeting held on 22 November in New York City. Organized jointly by ADDF and the Alzheimer’s Foundation of America (AFA), also based there, the conference brought together AD experts, with representatives from the National Institute on Aging (NIA), to brainstorm on how to increase the detection of dementia in primary care practice. According to the Patient Protection and Affordable Care Act signed into law in 2010, starting in 2011 Medicare will pay for an annual wellness visit, which includes the detection of any cognitive impairment. This change in policy provides an opportunity as well as a challenge to those interested in dementia care. “How do we go from our knowledge base of what is memory screening to something that fits into a wellness exam?” asked Fillit, laying out the charge to meeting participants. “We will need to put out some kind of guideline as an expert panel to give to the world in a peer-reviewed publication. It should lay out the steps for how we move forward.” Although the group did not settle on a definitive set of recommendations just yet, the discussions that day highlighted the need for identifying dementia early on, as well as the challenges to adding dementia screening and follow-up in an already crowded primary care system.
The AFA has been a strong proponent for dementia screening since its inception in 2002. “We knew there was a blood pressure screening day, so we asked ‘Why isn’t there a memory screening day?’ But when we proposed the idea it came under attack,” AFA president Eric Hall told meeting participants. Despite the criticism, AFA instituted an annual National Memory Screening Day in 2003. It is held every November. Although the event remains somewhat controversial among healthcare professionals, this year it drew a record 60,000 people who were concerned about their memory and wanted to be tested. “This tells us that we are going in the right direction; there is a need for what we are doing,” Hall told ARF. On 15 November 2011, healthcare professionals offered free, confidential memory screenings to the public at over 2,500 sites nationwide, including pharmacies, malls, and senior centers.
In the doctor’s office, dementia continues to be woefully under-detected. Malaz Boustani, Indiana University School of Medicine, Indianapolis, conducted an extensive review of the literature in 2003 on behalf of the U.S. Preventive Services Task Force (USPSTF) and concluded that 66 to 80 percent of dementia cases are unidentified in primary care (Boustani et al., 2003). Several presentations at the AFA-ADDF meeting confirmed that the situation has not improved since then. (These presentations are described in Part 2 of this series.)
“Why is dementia not being screened for?” asked Richard Stefanacci, University of the Sciences in Philadelphia, Pennsylvania, in his presentation. “One in a hundred patients ask to be screened. Unfortunately, primary care physicians tend to be reactive; they have to have a patient or caregiver complain before they investigate,” he answered his own question. Moreover, Stefanacci said, “Physicians don’t feel it pays them to make the diagnosis, in part because they are not convinced that there is anything they can offer Alzheimer’s patients.”
Although there is no cure for AD, presenters argued that screening can allay fears (if the test result is negative) or reveal other underlying conditions, such as hypothyroidism, depression, malnutrition, diabetes, that might be affecting cognition. “There are some reversible causes of cognitive problems, but even if those problems are due to Alzheimer’s dementia, for some individuals it may be better to know than not to know,” Lori Frank from MedImmune, Gaithersburg, Maryland, told ARF. In her presentation, Margaret “Marge” Dean of Texas Tech University Health Sciences Center School of Medicine at Amarillo explained that having a diagnosis of dementia can help patients and their families plan for the future. “If everyone has a better idea of what is coming down the line, you have improved their lives,” she said.
Most importantly, meeting participants argued that identifying dementia can improve a patient’s overall medical care and reduce the number of hospitalizations. Soo Borson, University of Washington, Seattle, told ARF that there is evidence from several different kinds of studies that persons with dementia need specialized care. For example, it happens that a patient’s treatment for heart disease or diabetes is ineffective because the person also has undiagnosed dementia and is forgetting to take medications or to follow instructions. “We need to move away from the concept of treating dementia, but rather look at dementia as the organizing principle for treating all of a patient’s healthcare needs,” said Frederick Schmitt of the University of Kentucky Medical Center in Lexington. “If you are demented, your healthcare is going to be affected.”
Among older patients coming to primary care, can a brief screen flag most of those with cognitive impairment? Image credit: Soo Borson
Studies have shown that patients with dementia who receive dementia-specific care have a better quality of overall medical care than those not receiving such care (Callahan et al., 2006; Vickrey et al., 2006; Boustani et al., 2011). But missing from the literature is a prospective randomized trial that follows cognitively normal people and shows that, in the long run, those who are screened for cognitive impairment fare better than those who aren’t. “We know that screening improves detection, but not if it improves outcome,” Borson told ARF. The lack of this kind of evidence is why the USPSTF, which makes recommendations about screening and other preventive services, concluded both in 1996 and 2003 that there was insufficient evidence to support dementia screening in the primary care setting (see Screening for Dementia: Recommendations and Rationale, USPSTF).
At the meeting, participants also debated the cost effectiveness of dementia screening. In her presentation, Paige Lin of Tufts Medical Center in Boston showed that among Medicare recipients 65 to 85 years of age, those with dementia have higher healthcare expenses than those without. Detecting dementia early on and providing the necessary care to patients could reduce those costs. However, “the efficacy of screening depends on several factors, such as test accuracy, screening frequency, the level of dementia risk in the target population, and most importantly, the downstream costs of care after detecting dementia. Currently, there are very few published studies on the cost effectiveness of dementia screening,” wrote Lin in an e-mail to ARF. “We need better data that demonstrate the value of screening by considering both the benefits and the costs.”
Although evidence on outcomes is lacking—and there was some debate at the meeting about precisely what kind of data are needed—what is in place are several screening tests that are effective in detecting dementia. Boustani, who was one of the scientists on the dementia screening USPSTF, found evidence of high accuracy for tests like the Memory Impairment Screen (MIS), the Mini-Cog (Borson et al., 2005), and the AD8 (Galvin et al., 2007; see also ARF Webinar). Separately, several presenters who described results of different dementia screening projects also came to the conclusion that these tests all work. (Those presentations are described in Part 2 of the series.) “One of the highlights of the meeting for me was the recognition that we have good screening tools and some work well in the primary care setting,” said Borson.
In the future, the diagnosis of dementia and cognitive impairment will be enhanced by various biomarkers currently being used in research settings, according to John Morris at Washington University School of Medicine in St. Louis. Once FDA approved and validated for clinical use, the PET amyloid imaging agent AV-45/florbetapir (see ARF related news story) or others like it “could be used widely,” Morris told ARF, adding, “I believe that is coming.” One caveat is that it is unclear at this point whether Medicare will pay for the scans.
If good screening tests are at hand, then the problem may be one of too many choices. In his presentation, J. Wesson Ashford of Stanford University in Palo Alto, California, reviewed the hundreds of tests available to clinicians. Ashford, who chairs AFA’s memory screening advisory board, argued that in future, testing should be done primarily using computers. “Computer calculation of test performance can give a much more meaningful indication of an individual's performance, improving the sensitivity and specificity of any test and considerably improving the cost effectiveness of screening,” he wrote in an e-mail to ARF.
For now, the Centers for Medicare & Medicaid Services (CMS) has asked the NIA to provide guidance on which test should be used to screen for cognitive impairment during the annual wellness visit. “It should be evidence based, appropriate for the Medicare population and providers, brief and easy to use, and cost is a consideration as well,” said NIA’s Molly Wagster, speaking at the AFA-ADDF meeting with her colleague Nina Silverberg. NIA so far has identified 12 tests that are free of cost and take less than five minutes to administer. These include the AD8, Mini-Cog, and MIS, among others. However, “there is no consensus as to which tests are the best or what to recommend to a primary care physician,” said NIA’s Creighton (Tony) Phelps, who did not attend the conference in New York City. NIA has already held several meetings with representatives from other federal agencies and dementia experts, and is continuing to collect input.
Even once a test, or group of tests, is officially anointed for screening, “dementia screening is going to be challenging to do,” said Morris. Busy primary care physicians have to find time to screen for dementia among the many other health conditions that typically afflict older patients; moreover, they may not have time or resources to conduct the follow-up evaluation on a positive screen, or to find dementia-specific care for a patient. Low reimbursement rates only compound these difficulties.
AFA-ADDF meeting participants will continue discussions by phone over the next several weeks with the goal of hammering out a set of recommendations that address some of these challenges. If the task may seem daunting, there is no lack of enthusiasm. “The policy changes that have occurred in Medicare, the field’s interest in the earliest stages of disease as indicated by the new diagnostic guidelines, and the greater focus on prevention are all very exciting and energizing,” Frank told ARF.—Laura Bonetta.
This is Part 1 of a two-part series. See also Part 2.
Screening Tests Are Accurate, But Patients Don’t Follow Up
The Dementia Screening and Detection Meeting, held on 22 November in New York City, hosted a day of data exchange and debate toward a set of joint recommendations for improving dementia detection in primary care practice. Meeting participants shared, some for the first time, results of dementia-screening programs conducted as part of research studies. The Alzheimer’s Drug Discovery Foundation (ADDF) and the Alzheimer’s Foundation of America (AFA), both based in New York City, organized the meeting.
A common theme running through the presentations, regardless of patient population or setting, was that many of the available cognitive screening tests are effective in detecting dementia, but that a large proportion of patients who screen positive on those tests do not return for further follow-up. Frederick Schmitt, University of Kentucky Medical Center in Lexington, presented preliminary screening results from the PREADVISE (Prevention of AD with Vitamin E and Selenium) study. This trial piggybacked on a larger one (the SELECT trial) being conducted by the National Cancer Institute on the effects of the supplements in reducing prostate cancer. PREADVISE investigators conducted annual cognitive screens on 7,546 men over 65 years of age (or over 60 if they were African-American) who enrolled in the cancer study and were followed for seven to 11 years.
To detect dementia, the investigators used a cut-off score of 5 on the Memory Impairment Screen (MIS), a four-minute, four-item delayed free and cued recall memory test (Kuslansky et al., 2002). The cancer study ended in 2008, seven years after it started, because a futility analysis indicated that the supplements were not beneficial but harmful. When the SELECT trial ended, PREADVISE investigators who had been performing the MIS in person at SELECT trial sites switched to screening participants by phone using a telephone version of the test; the last screen is planned for 2013.
This changing of methodology may complicate the interpretation of results. “We had 9 percent of people failing the MIS by telephone versus 1.6 percent in person,” said Schmitt. He was unsure about the reason for this difference between the two types of test, but suggested the higher failure rate of the telephone MIS could simply reflect the fact that the men being screened by telephone had become older (since this type of screen was done at a later stage of the trial), and thus more of them would have cognitive problems.
People who failed either the in-person or telephone MIS were invited for follow-up and more extensive evaluation for dementia. Two-thirds took up the offer. “Even though this is a research population volunteering for a cancer study, we see the same results as other studies: no return on positive screen, physician reluctance to follow up, noise on comorbidities,” said Schmitt.
The dropout rate in PREADVISE was consistent with findings presented by Malaz Boustani, Indiana University School of Medicine in Indianapolis. He offered cognitive screening to 825 participants enrolled in the Indianapolis Dementia Screening and Diagnosis study. Whereas 97 percent of study participants agreed to be screened for dementia, half of those who screened positive did not return for further follow-up. “We were really surprised about that,” said Boustani.
Switching gears, David Salmon of the University of California, San Diego, presented results of a screening service set up for primary care physicians in the San Diego area. Physicians suspecting that a patient might be cognitively impaired could refer that patient to the screening service at no charge. (The Alzheimer's Research Centers of California and the National Institute on Aging funded the screening.)
Salmon and colleagues conducted a fairly extensive screen which involved taking a history of memory and medical problems, a test for depression, and a memory screening test battery consisting of the Mini-Mental State Examination (MMSE); Wechsler Memory Scale-Revised (WMS-R) Logical Memory Test, which probes immediate and delayed recall; the Trail Making Test parts A and B, in which patients are asked to connect numbers and/or letters in a sequential order; and the Seven Minute Screen for Dementia, which includes the Benton orientation test, enhanced cued recall test, clock drawing test, and semantic verbal fluency test (Solomon et al., 1998). The scores were compared to those of cognitively normal, healthy people. Based on that comparison, the patient was classified as having high, moderate, low, or undetermined probability of dementia.
The screening service saw about 150 people per year. After the first 519 people had been screened, Salmon and colleagues analyzed the findings. This revealed that 196 people had two or more cognitive deficits, indicating possible dementia; 80 had signs of depression; 64 only had memory problems, indicating possible mild cognitive impairment (MCI); 137 had no cognitive deficits; and 42 had other problems, such as stroke, that complicated diagnosis.
Of the people screened, 133 had MMSE scores in the upper twenty-fifth percentile—in other words, normal. Yet 47 percent of those 133 had inappropriate responses on immediate recall, and 61 percent had impaired delayed recall; both deficits were detected using the WMS-R Logical Memory Test. “If the MMSE is all the physician can do, we would not see memory impairment in those people,” said Salmon. The Seven Minute Screen for Dementia is a more detailed test than the MMSE. But with that test, too, 29.5 percent of people with low probability of dementia nonetheless had problems with immediate recall and 39.2 percent with delayed recall.
A year and a half later, Salmon and colleagues retested some of the patients. They found that 12 people who had tested normal in the first screen and five people who were depressed showed no cognitive decline in the second screen. On the other hand, eight people with MCI on the first screen and five people identified as being demented showed a decline in MMSE scores. “This provides a bit of validity for the screen,” said Salmon. “If we call someone impaired, they do actually decline.”
He also looked at whether the primary care physicians who referred their patients to the service were using the information provided. Salmon and colleagues looked at patients’ charts six months after they were screened, and in 75 percent of cases the physician had made a note that he or she had discussed the test with the patient. In 65 percent of cases, the physician had recommended further workup, specialty referral, changes in treatment, or some other action. Salmon did not know, however, whether that action resulted in a better outcome for patients in the long run.
The study Salmon presented involved patients who were referred to be screened by their physicians. Another presentation instead focused on screening patients in a primary care setting in the absence of a physician’s recommendation. The project, presented by J. Riley McCarten of the University of Minnesota Medical School, Minneapolis, was conducted at seven Veterans Affairs (VA) medical centers within the VA Midwest Healthcare Network, in the states of Minnesota, North Dakota, South Dakota, Iowa, and Nebraska. At these centers, McCarten’s group put together teams including a coordinator familiar with treating dementia, a primary care physician, and a nurse trained to conduct cognitive screens. During routine primary care visits, the nurses screened veterans over 70 years old using the Mini-Cog test, which took 90 to180 seconds to administer. The test combines three-item recall with the clock-drawing test. When someone failed the test, which had a cut-off score of 3, the nurse had the following scripted response: “Based on the screening test, my recommendation is that we get further evaluation to help sort things out.”
Out of 43,023 patients seen at the clinic, nurses offered the screening to 8,342 people, primarily white men, over 70 years of age who had no previous diagnosis of dementia. Almost all (8,063) accepted. Of those screened, about a quarter failed the Mini-Cog test and 28 percent of those who failed said they would do a thorough diagnostic workup. Of those 580 people, 432 proved on follow-up to have dementia, 108 had cognitive impairment, and 40 had no cognitive impairment, i.e., were false positives.
On the flip side, of the 5,982 who passed the test, 118 requested a follow-up evaluation, and of those, 82 had dementia, 21 had cognitive impairment, and 15 had no cognitive impairment. This means that some people with dementia or cognitive impairment had escaped detection in the original screen (i.e., false negatives); the people who requested the follow-up knew subjectively that something was wrong, and the 15 who proved fine on the test and follow-up fall into a group researchers call the ‘worried well.’ McCarten also highlighted the fact that 132 of the patients screened had Mini-Cog scores of 0, and 256 patients had a score of 1, which indicates severe cognitive impairment, “yet there was no record they had anything wrong with them, again confirming that dementia goes undetected in the primary care system,” he said at the meeting.
The last presentation of the AFA-ADDF meeting dealt with a different type of screening, that is, one carried out in the community rather than a doctor’s office. Peter Bayley of the VA Palo Alto Healthcare System in California presented data from the AFA’s 8th annual National Memory Screening Day held 16 November 2010. The event engaged more than 2,300 sites that provide confidential memory screenings, including senior centers, libraries, long-term care residences, hospitals, doctors’ offices, and pharmacies. Volunteers ranging from medical students and nurses to physicians and retired physicians conducted the screenings. More than 60,000 people were screened on that day, but Bayley presented preliminary analyses on subsets.
The AFA allows sites to use the screening tool of their choice, and the seven that were most widely used by participating sites were: Mini-Cog, MIS, General Practitioner Assessment of Cognition (GPCOG), the Kokmen Short Test of Mental Status (Kokmen et al., 1991), MMSE, Montreal Cognitive Assessment (MoCA), and Saint Louis University Mental Status Exam (SLUMS). “All tests had very similar failure rates,” said Bayley in his presentation. Taking the results from 3,398 people tested on National Screening Day, Bayley found that, on average, 11.7 percent of participants failed their test. “This result was in agreement with published data that one in eight people aged 65 and over have AD,” he added.
In another analysis, Bayley looked at the proportion of people recommended for follow-up with their primary care physicians. Out of 2,420 people screened, 294 scored below normal on their test. The volunteer test administrators recommended that 94 percent of these 294 people (i.e., 276 people) follow up with their doctors for further evaluation. However, of the 2,126 people who passed their test, 47 percent (i.e., 999 people) were also recommended for follow-up. “Whether an individual was recommended for follow-up might depend on who is conducting the screening. We had a variety of healthcare providers involved at different sites, and they were likely to err on the side of caution,” Bayley told ARF. He is continuing to analyze the data and will present a fuller interpretation at the annual meeting of the American Association for Geriatric Psychiatry to be held in Washington, DC, in March 2012.
For Bayley, the central conclusion is that many people in the community want to be screened. “Regardless of whether you think screening is good or not, there is a level of concern in the community that needs to be addressed,” he told ARF.—Laura Bonetta.
This is Part 2 of a two-part series. See also Part 1.
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