Primary Care Physicians Show Greater Confidence in Diagnosing Alzheimer Disease Through DISCERN Skin Test
Physicians were nearly 3 times more likely to prescribe treatments for symptoms of suspected dementia with a positive DISCERN result.
A newly published decision-impact study on SYNAPS Dx’s DISCERN skin test, a combination of 3 biomarkers: morphometric imaging, protein kinase Cε (PKCε),and Alzheimer disease (AD)-index, showed that 90% of primary care physicians (PCPs) who used it were likely to order it again. Validated against autopsy confirmed diagnosis of AD, the DISCERN skin test, a first of its kind, had a significant impact on physician decision-making regarding AD diagnosis and management.
"With the potential FDA-approval of drugs for AD coming this year, payers will be facing challenges regarding prescribing and coverage determinations for new, expensive treatments for the most appropriate patients,” investigator Frederick Huie, MD, SDx advisory council member, said in a statement. "Physicians indicated they were not only more likely to diagnose AD with a positive DISCERN test result versus without a test, but also were more likely to establish an appropriate course of treatment, which may include prescribing disease-modifying drugs once they become available."
He added, "Physician confidence in diagnosing AD is becoming increasingly more important as data suggest that disease modifying treatments, including lifestyle and disease modifying drugs may slow cognitive decline."
A web-based survey to estimate treatment decisions was completed by 250 PCPs, 102 neurologists, and 50 geriatricians. Computer software was used to randomly generate hypothetical patient profiles with 5 attributes: MRI/CT scan results, Mini-Mental State Examination (MMSE) scores, blood test results (TSH, vitamin B12, folate, syphilis, Lyme disease), age, and DISCERN result. The goal of the study was to evaluate the clinical utility of the test and asses how physicians would use the test in real-world situations to inform patient diagnosis and management.
Each physician viewed between 7 and 27 uniquely generated profiles, and indicated whether they would diagnose the patient with AD, prescribe medications indicated to treat AD symptoms, refer the patient to a neurologist, and prescribe a futuristic disease-modifying drug. Coming into the study, less than half (48%) of the surveyed physicians reported they were satisfied (44%) or extremely satisfied (4%) with current methods for assessing AD. Satisfaction was lower in PCPs (40%) than neurologists (64%).
The high rate of physicians who reported they would order DISCERN was for several reasons, including ability to aid in treatment decision-making (69%), less invasiveness compared with cerebrospinal fluid (CSF) testing (67%), high accuracy (67%), and ability to provide an objective, definitive AD diagnosis (66%). A conjoint analysis of 388 physicians showed statistically significant (α=0.05) impact on all decisions-making outcomes relative to no testing, aside for referral to a neurologist.
While a positive result on DISCERN increased the odds of definite diagnosis of AD (OR, 6.45; 95% CI, 5.09-8.17), a negative result associated with significantly lower odds of diagnosis (OR, 0.39; 95% CI, 0.32-0.48). With a positive result, clinicians were 2.98 times more likely to prescribe treatments for symptoms of suspected dementia (95% CI, 2.40-3.68), and were more likely to prescribe a disease-modifying therapy (OR, 4.12; 95% CI, 3.36-5.04).
"Our study demonstrates that the DISCERN test is an objective contributor to physician decision-making, associated with significantly higher clinician confidence in an AD diagnosis, especially in those recently diagnosed with dementia," Frank Amato, chief executive officer and president at SDx, said in a statement. "The availability of a test like DISCERN is of critical importance as the Alzheimer’s Association recently noted that 50-70% of symptomatic patients are misdiagnosed in the primary care setting, primarily due to the lack of objective, easily accessible, time- and cost-effective, accurate diagnostic tools."
Above all, the DISCERN result ranked as the most important attribute in physician decision-making regarding diagnosis and management of patients with suspected dementia. Relative attribute importance by physician type was calculated from Hierarchical Bayesian models, with neurologists (54%) ranking the DISCERN result as the most important attribute for helping prescribe treatments for symptoms of suspected dementia relative to PCPs (47%) and geriatricians (45%). All 3 groups equally ranked the DISCERN test as the most important attribute when diagnosing AD (55%, 55%, and 54%, respectively), and prescribing future disease-modifying therapies (53%, 53%, and 51%). Notably, DISCERN was the most important attribute for geriatricians when referring a patient to a neurologist (29%) whereas MMSE score was the most important attribute for that of PCPs (30%).