Initial Diagnosis of Alzheimer’s Dementia and Mild Cognitive Impairment Varies by Care Setting in Large Health System

Ivana A. Vaughn, PhD, MPH1, Hwasoo Shin, PhD1, Angelos Katramados, MD, MMM, MSc2,3, Laila Poisson, PhD1,2, Kelly Tundo, RN, BSN, CCRP2,Marina Novikova, DO2,3, Brien Smith, MD, MBA2, Lonnie Wen, RPh, PhD4, Raymond Zhang, MSc4, Quanwu Zhang,PhD4, Amir Abbas Tahami Monfared, MD, PhD4,5

1Henry Ford Health Department of Public Health Sciences, Detroit, MI, USA; 2Henry Ford Health Department of Neurology, Detroit, MI, USA; 3Wayne State University, Detroit, MI, USA;  4Eisai Inc., Nutley, NJ, USA; 5McGill University, Montreal, QC, Canada.

Key Takeaways

Nonspescified cognitive symptoms and MCI had highest proportion of diagnosis in Primary Care compared to Neurology

Neurology provided more granular staging for AD compared to Primary Care

Stage-appropriate assessment and decision supports in Primary Care might help improve diagnosis of AD

Early Diagnosis of Dementia

Timely diagnosis and staging of Alzheimer’s disease (AD) are essential for appropriate evaluation, care planning, and referral.

Primary care (PC) is often the first point of contact for patients and families reporting cognitive concerns.

We described how frequently MCI/AD diagnoses and AD severity stages are documented at the initial outpatient visit in PC versus neurology.

Leveraging Electronic Health Records

Data Source: Henrry Ford Health outpatient encounters January 2016 – June 2024

Study Design: Retrospective analysis

Eligibility: Age ≥ 40 years with ICD-10 cognitive symptoms, MCI or AD diagnosis

Index encounter: First ICD-10 diagnosis of cognitive symptoms, MCI or AD diagnosis within study period

Groups	ICD-10 Codes	Description
Cognitive symptoms w/o diagnosis	R41.81, R41.840–R41.844, R41.3, R41.85, R41.89, R41.9	Age-related cognitive decline; deficits in attention, concentration, visuospatial, executive, or psychomotor functions; amnesia; anosognosia; other/unspecified cognitive symptoms.
Mild neurocognitive disorder	G31.84, F06.70, F06.71	Mild cognitive impairment (unspecified/uncertain etiology); mild neurocognitive disorder due to known physiological condition (without/with behavioral disturbance).
Mild AD	G30.0–G30.9 + F02.A0–F02.A4	Alzheimer’s disease etiology (early-onset, late-onset, other, or unspecified) plus mild dementia with or without agitation, behavioral, psychotic, mood, or anxiety disturbances.
Moderate AD	G30.0–G30.9 + F02.B0–F02.B4	AD etiology plus moderate dementia, with specifiers (none, agitation, behavioral, psychotic, mood, anxiety).
Severe AD	G30.0–G30.9 + F02.C0–F02.C4	AD etiology plus severe dementia, with specifiers (none, agitation, behavioral, psychotic, mood, anxiety).
Unstaged AD	G30.0–G30.9 ± F02.80–F02.84	AD etiology documented, but severity not staged (unspecified dementia with or without behavioral/psychotic/mood/anxiety disturbance).

 

Limitations

Index encounters based on first visit to Henry Ford Health with ICD-10 diagnosis of AD symptoms; therefore, some patients may have been referred into the health system by external providers

Comprehensive identification of AD symptoms may require additional manual chart review of clinic notes for symptoms not captured with coding

Longitudinal data exploration should further define the evaluation and diagnostic journey

Clinical Impact

Interventions designed to enhance clinical decision support, education and training will improve staging and diagnosis

Multidisciplinary care coordination could have important implications for AD care pathway

Standard clinical practice guidelines should be further defined for AD system of care that includes both primary and specialty care

Future studies should explore diagnostic assessments used by neurologist compared to other specialties

Figure 1: Mosaic Plot of Index Encounters Neurology vs Primary Care by AD Severity

Figure 2:  Bar Graph of Index Encounter Neurology vs Primary Care by AD Stage

Table 2:Sociodemographic by Medical Specialty
Characteristic	Neurology N=10,774	Primary Care N=24,875	P-value
Age	67.3(13.2)	71.9(13.6)	<0.01
Sex			<0.01
Male	4,651 (43.2%)	9,586 (38.5%)
Female	6,123 (56.8%)	15,289 (61.5%)
Race			<0.01
White	7,907 (77.6%)	17,966 (74.9%)
Black	1,771 (17.4%)	5,083 (21.2%)
Asian	155 (1.5%)	478 (2.0%)
Native American	32 (0.3%)	63 (0.3%)
Other	325 (3.2%)	404 (1.7%)
Ethnicity
Hispanic	232 (2.4%)	546 (2.3%)	>0.90
Middle Eastern/ North African	381 (4.0%)	387 (1.7%)	<0.01
Insurance
Commercial	5,372 (49.9%)	12,582 (50.6%)	0.20
Medicare	8,190 (76.0%)	20,346 (81.8%)	<0.01
Medicaid	2,202 (20.4%)	3,202 (12.9%)	<0.01
Dual Eligible	79 (0.7%)	123 (0.5%)	0.01
N (%) or mean(Std dev). P-value < 0.05 using Chi-square or Welch’s t-test.

 

Table 3: Comorbidities by Medical Specialty
Characteristic	Neurology N=10,774	Primary Care N=24,875	P-value
Comorbidities
Myocardial infraction	229 (2.1%)	691 (2.8%)	<0.01
Congestive heart failure	564 (5.2%)	2,163 (8.7%)	<0.01
Peripheral vascular disease	607 (5.6%)	2,153 (8.7%)	<0.01
Cerebrovascular disease	1,335 (12.4%)	2,063 (8.3%)	<0.01
Chronic pulmonary disease	956 (8.9%)	3,674 (14.8%)	<0.01
Connective ulcer disease	202 (1.9%)	534 (2.1%)	0.10
Peptic ulcer disease	77 (0.7%)	209 (0.8%)	0.20
Hemiplegia or paraplegia	62 (0.6%)	94 (0.4%)	0.01
Renal disease	719 (6.7%)	3,113 (12.5%)	<0.01
Any malignancy	575 (5.3%)	1,553 (6.2%)	<0.01
Metastatic solid tumor	109 (1.0%)	211 (0.8%)	0.13
Diabetes	1,707 (15.8%)	6,288 (25.3%)	<0.01
Liver disease	97 (0.9%)	250 (1.0%)	0.40
Charlson Comorbidity Index	1.0(1.6)	1.3(1.8)	<0.01
CCI > 0			<0.01
0	6,290 (58.4%)	11,387 (45.8%)
1	1,912 (17.7%)	5,355 (21.5%)
>1	2,572 (23.9%)	8,133 (32.7%)
N (%). P-value < 0.05 using Chi-square or Welch’s t-test

Acknowledgements

Funding provided by Eisai Inc and HFH Neurology.

Eisai had no role in study design, data collection, analysis, decision to publish, or preparation of the poster

Special thanks to HFH Public Health Sciences Research Analytics