INTRODUCTION

Dementia is common among older adults and is associated with high rates of healthcare utilization.1 However, studies suggest that up to half of patients with dementia remain undiagnosed.2 Our objective was to determine healthcare utilization rates among patients with undiagnosed dementia.

METHODS

We identified patients who developed dementia while enrolled in the Adult Changes in Thought (ACT) study, a prospective cohort study of older adults enrolled in Group Health (GH), an integrated healthcare system. ACT participants are assessed for dementia every 2 years, with abnormal results leading to a detailed diagnostic evaluation.3 For each of the 980 ACT participants who were diagnosed with dementia between 1994 and 2014, we examined GH electronic health data in the 2 years prior to diagnosis in ACT to determine whether dementia was recognized by their healthcare providers before diagnosis within the ACT research study. If a dementia diagnosis, memory complaint or dementia medication was found in the participant’s GH electronic health data prior to diagnosis in ACT, the participant was classified as having “diagnosed dementia” (n = 544); otherwise, the participant was classified as having “undiagnosed dementia” (n = 436). For each undiagnosed case, we randomly selected three participants, matched on age, gender and date of ACT visit (±180 days), who did not develop dementia while in ACT to serve as our “no dementia” group (n = 1308).

The number of outpatient visits, “no-shows” for scheduled outpatient visits, emergency department visits and hospitalizations were obtained from GH electronic utilization data for the 2-year period before the index ACT study dementia screening visit. We describe characteristics and healthcare utilization patterns of participants with diagnosed dementia, undiagnosed dementia and no dementia over 2 years. We used age-adjusted conditional logistic regression to formally compare participants with undiagnosed dementia and those without dementia.

RESULTS

In terms of baseline characteristics, participants with undiagnosed dementia appear to represent an intermediate group between participants with diagnosed dementia and those with no dementia (Table 1). For example, 35% of participants with diagnosed dementia had cerebrovascular disease, compared to 22% of participants with undiagnosed dementia and 10% of participants with no dementia (p < 0.001, undiagnosed vs. no dementia).

Table 1 Baseline Characteristics of Patients with Undiagnosed Dementia and No Dementia
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In terms of healthcare utilization, participants with undiagnosed dementia again appear to be an intermediate group between participants with diagnosed dementia and those with no dementia (Table 2). Participants with diagnosed dementia had 2.5 emergency department visits over 2 years, compared to 1.7 visits for undiagnosed participants and 0.8 visits for participants with no dementia (p < 0.001, undiagnosed vs. no dementia).

Table 2 Two-Year Healthcare Utilization Patterns of Patients with Diagnosed Dementia, Undiagnosed Dementia and No dementia
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We saw similar patterns when examining the proportion of participants with at least one visit. For example, 53% of diagnosed dementia participants had at least one clinic “no-show” over 2 years, compared to 43% of undiagnosed dementia participants and 29% of no dementia participants (p < 0.001, undiagnosed vs. no dementia). Similarly, 46% of diagnosed dementia participants had at least one hospitalization, compared to 31% of undiagnosed participants and 21% of participants with no dementia (p = 0.02, undiagnosed vs. no dementia).

DISCUSSION

Leveraging data from a large prospective cohort study of dementia embedded within an integrated healthcare system with excellent healthcare utilization data, we found that patients with undiagnosed dementia were an intermediate group between patients with diagnosed dementia (most healthcare needs) and no dementia (least healthcare needs). Compared to patients without dementia, patients with undiagnosed dementia were more likely to “no-show” for scheduled appointments, to visit the emergency department and to be hospitalized.

One explanation for these findings is that patients with undiagnosed dementia have an intermediate comorbidity burden compared to patients with diagnosed dementia and those with no dementia, resulting in the observed intermediate healthcare utilization. However, previous studies have found that accounting for comorbidity burden did not fully explain higher healthcare utilization in dementia patients,4 suggesting there may be additional reasons why dementia patients may utilize more healthcare. Specifically, patients with undiagnosed dementia may be less able to access care due to forgotten appointments and increased “no-shows,” resulting in the higher rates of emergency department visits and hospitalizations. Identifying patients with undiagnosed dementia may allow for targeting of support services to remind patients and caregivers about appointments. These reminders may reduce “no-shows” and lead to fewer emergency department visits and hospitalizations, which are often distressing for cognitively impaired patients and costly to the healthcare system.5