A. Shah1, O. Ysea-Hill2, A. Torres-Morales3, C.J. Gomez2, A. Castellanos2, J.G. Ruiz2,3,4
1. Memorial Healthcare System, Hollywood, Florida, USA; 2. Miami VA Healthcare System Geriatric Research, Education and Clinical Center (GRECC), Miami, Florida, USA; 3. University of Miami / Jackson Health System, Miami, Florida, USA; 4. University of Miami Miller School of Medicine, Miami, Florida, USA
Corresponding Author: Jorge G. Ruiz, MD, Associate Director for Clinical Affairs, Miami VA Healthcare System, Geriatric Research, Education and Clinical Center (GRECC), GRECC (11GRC), Bruce W. Carter Miami VAMC, 1201 NW 16th Street, Miami, Florida 33125, USA, Telephone: (305) 575-3388 / Fax: (305) 575-3365, E-mail: firstname.lastname@example.org, ORCID: 0000-0003-3069-8502
J Prev Alz Dis 2022;
Published online January 18, 2022, http://dx.doi.org/10.14283/jpad.2022.14
Evidence suggests that dementia can be prevented. Patients with frailty may be particularly at risk for cognitive impairment (CI). The aim of this study was to determine dementia risk in older Veterans and whether the risk varies according to frailty status. We also evaluated the feasibility of mailed dementia risk screening. Participants were mailed a questionnaire and the Self-Administered Gerocognitive Examination (SAGE). High dementia risk was defined as having mild cognitive impairment (MCI) on SAGE or a CAIDE score ≥6. Out of 5,432 mailed surveys, we obtained a response rate of 19.75%. Most responders completed the questionnaire items. We identified a total of 689 (75.9%) subjects to be at high risk for dementia. Individuals with frailty were at a greater risk for dementia when compared to robust individuals OR:1.921 (95%CI:1.259-2.930), p=.002. The mailed screening represents a convenient, alternative and scalable approach to screen for dementia risk.
Key words: Dementia risk, mild cognitive impairment, dementia.
Most types of dementia are secondary to neurodegenerative disorders which are generally deemed progressive and incurable (1). However, growing evidence suggests the possibility that dementia may be prevented by targeting modifiable risk factors (2-6). A group at particular risk for dementia is individuals with baseline frailty, a state of vulnerability to stressors due to multisystemic dysfunction, which is associated with poor clinical outcomes (7). Epidemiological evidence demonstrates that these conditions often coexist with over half of patients with frailty having concurrent cognitive impairment. In longitudinal studies the onset of frailty may lead over time to dementia (7). Identifying frailty may lead to a more targeted screening of these patients for dementia risk.
Screening for dementia risk will lead to the early identification of those patients at higher risk, allowing clinicians to implement early interventions addressing modifiable risk factors. Practical approaches to increase dementia risk screening are needed to ensure successful population-based implementation. The study aim was to determine the risk of dementia in community-dwelling older Veterans and whether the risk varies according to frailty status. A secondary aim was to ascertain the feasibility of administering dementia screening using a mailed questionnaire.
Study Design, Setting and Participants
This cross-sectional study was conducted at a government-run, US Veterans Health Administration (VHA) Medical Center, an integrated healthcare organization in the US Southeast. Participants included 5,432 community-dwelling Veterans 50 years and older who had at least 2 visits from July 2018-June 2019. Patients with baseline diagnosis of cognitive impairment (MCI or dementia) were excluded. A battery of questionnaires, including socio-demographic, education and exercise surveys, and the SAGE test (Self-Administered Gerocognitive Examination) were mailed to the participants’ addresses on file from July, 2019 to April, 2020. This study was reviewed and approved as a quality improvement project by the Miami VA Healthcare System IRB, therefore, informed consent was not required.
Outcomes and Measurements
For the purposes of this study, we defined dementia risk as either having a high score in the CAIDE or mild cognitive impairment (MCI) in the SAGE.
Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE)
This validated risk score predicts the risk of late-life dementia. The CAIDE Dementia Risk Score was validated in a multiethnic American population, similar to our participants, and has been used for participant selection in several multi-domain lifestyle trials for preventing cognitive decline (8, 9). The CAIDE variables include age, hypertension, hypercholesterolemia, physical inactivity, obesity and educational level (8). The information regarding education and physical activity was collected from the mailed questionnaires whereas age, gender, systolic blood pressure (SBP), body mass index (BMI) and total cholesterol were retrieved from the electronic health record (EHR) within one year of their second visit. The scores range from 0 to 15. In this study, a CAIDE score of ≥6 indicated a high risk for dementia. In a large population-based, cohort study, a CAIDE score ≥6, demonstrated a higher probability of dementia in 20 years (8).
Mild Cognitive Impairment
The Self-Administered Gerocognitive Exam (SAGE) is a validated instrument that evaluates the cognitive domains of orientation, language, memory, executive function, calculation, abstraction, and visuospatial abilities. The SAGE has been used in community mild cognitive impairment and dementia screening in the USA. It is self-administered, brief and has good sensitivity (79%) and specificity (95%) at detecting MCI. The SAGE is a 12-item, self-administered test that takes 10-15 minutes to complete and whose scores range between 0 and 22 points (10). There are four alternative versions of the SAGE designed to avoid testing effects (11). In this study, we used the SAGE form 1. SAGE scores between 17 and 22 indicate normal cognition, 16 and 15 MCI, and 14-or-less suggest the presence of dementia . The SAGE has a 79% sensitivity and 95% specificity in determining cognitive impairment (10).
We used the 31-item VA-FI (Table 1) which is based on a deficit accumulation conceptual framework. The items belong to five major domains: morbidity, function, sensory loss, cognition and mood, and other (miscellaneous items). The VA-FI is calculated by adding up the number of deficits obtained from the patient and dividing by 30 (total number of health deficits). For each variable, the presence of the deficit was scored as 1 whereas its absence was scored as 0. Participants were then categorized as robust (<0.10), pre-frail (0.10-0.20) and frail (≥0.21) based on previously published cut-off points (12). For each patient, the frailty index was automatically generated from EHR data on the date of the geriatric primary care visit between September 1, 2019 and May 31, 2020.
SD= standard deviation; n= number of participants; BMI= body mass index; VA-FI= VA Frailty Index; MCI= mild cognitive impairment. The assigned superscript letters (a, b or c) are representative of the low risk, high risk (CAIDE ≥6) and high risk (MCI) groups. If a pair of values is significantly different, the values have different subscript letters assigned to them. If a pair of values are not significantly different, the values will have the same superscript letters assigned to them. Data without superscripts is not significantly different between dementia risk groups. Significant differences are in bold (p<.05)
We mailed 10,152 packages in 2 waves. During wave 1, 5,432 packages were mailed from July 8th, 2019 through January 17th, 2020. Those participants failing to respond within 2 months of the first correspondence (n=4,720), received a second package between October 10th, 2019 through April 4th, 2020. Each package included: 1) Cover letter; 2) SAGE; 3) Questions on physical activity and education; and 4) Stamped self-addressed envelope. All responses received on or before May 31st, 2020 were included in the study. The SAGE was manually scored, and the information was recorded on the dataset. Patients with SAGE scores were ≤ 14 (consistent with dementia) were excluded.
We reported descriptive sociodemographic characteristics. Categorical variables were presented as frequency (percent), and continuous variables as mean ± SD. Normality of the distribution was checked using the Kolmogorov-Smirnov test. For categorical and continuous variables, Pearson chi-square and Mann-Whitney tests were used, respectively. In addition, we used binomial logistic regression to calculate the association between frailty (independent variable) and the risk of developing dementia (dependent variable), after adjusting for race, ethnicity, marital status, smoking history, alcohol and substance abuse, obstructive sleep apnea and use of anticholinergic drugs. We determined feasibility by calculating the number and proportion of participants who completed all the items in the demographic survey and the SAGE questionnaire. Any questions left unanswered on SAGE were considered incorrect as per test instructions. All analyses were performed using SPSS 26.0 for Windows (SPSS, Inc., Chicago, Illinois). All statistical tests were two-tailed and statistical significance was assumed for a p-value <0.05.
We received 1073 responses (19.8%), 165 had a positive screen for dementia (SAGE score of ≤ 14). The remaining participants were 908 Veterans, 95.5% males, mean age 68.27 (SD=8.36, range 51-96) years, 59.9% Caucasian, 68.5% non-Hispanic and 54.4% married (Table 1). As compared with non-responding individuals, responders were more likely to be older, Caucasian, Hispanic, and married. There were no differences in terms of gender or frailty status between responders and non-responders (Supplementary Table 1).
Most participants were at high risk for dementia (n = 689, 75.9%): 127 (18.4%) had MCI, and 562 (81.6%) had a CAIDE score of ≥6. Other than a higher mean VA-FI score in those with MCI (0.22, SD=0.11) as compared to the CAIDE score ≥6 subgroup (0.19, SD=0.10), p<001, the high dementia risk subgroups were not significantly different in their baseline characteristics. When compared to participants at low risk for dementia, patients in the high-risk group had lower levels of education, higher BMI and were more likely to be frail. (Table 1).
Dementia Risk and Frailty
The proportions of robust, pre-frail and frail Veterans were 25.9% (n=235), 38.7% (n=351) and 35.5% (n=322), respectively. The proportion of robust patients at high risk for dementia (66.4%, n=156) was significantly lower than the pre-frail (76.9%, n=270) and frail groups (81.7%, n=263), p<.001. Pre-frailty and frailty were significantly associated with an increased risk of dementia when compared to the robust status, adjusted OR:1.586 (95%CI:1.083-2.322), p=.018 and OR:1.921 (95%CI:1.259-2.930), p=.002, respectively (Table 2).
*Covariates: Race, ethnicity, marital status, smoking history, alcohol and substance abuse, obstructive sleep apnea and use of anticholinergic drugs
Most respondents completed the mailed survey required items: questions about physical activity (94.4%, n=1013), years of education (95.4%, n=1024) and the SAGE (96.6%, n=1036) items.
We found a high prevalence of dementia risk in this sample of community dwelling Veterans. As expected, frailty was associated with a higher risk for dementia. The use of a mailed screening was feasible and convenient, and may serve as an alternative, and scalable approach to identify individuals at risk for dementia.
Most studies on the prevalence of dementia risk have used community-based samples as part of cross-sectional or cohort studies where participants were screened on site. The high prevalence of dementia risk in our study is consistent with previous studies using a CAIDE cut-off score of ≥ 6 in Japanese American men and Finish samples of all genders ranging from 75% to 99% (8, 13, 14). However, there are no previous studies on the prevalence of dementia risk in the US Veteran population. The high prevalence of dementia risk in our study has several explanations. Forty percent of our sample consisted of minority groups, 95% were males, 43% were obese, 38.1% were sedentary, and over one third frail, groups that in most studies have shown the highest risk for cognitive impairment. Furthermore, studies in US male veterans demonstrate a high prevalence of cardiovascular risk factors which are often associated with a higher risk for dementia (15). In addition to the high prevalence of cardiovascular risk, veterans show higher rates of medical multimorbidity (16) and mental illness (17) that may further contribute to a higher incidence of cognitive impairment. Unlike community samples, veterans may be more representative of patients in health care settings. Most of these patients may be identified as at risk for dementia when seeking routine medical attention at health care facilities. However, many individuals may not regularly receive on-site care at health care institutions. The use of postal screening may serve as a convenient, scalable, and alternative population-based strategy for outreach dementia risk screening of high-risk individuals who would not otherwise actively seek health care.
Unlike previous studies including volunteer participants in cohorts or randomized controlled trials, this study investigated patients seeking medical care at an integrated healthcare system. Population studies estimations suggest that up to 30% of all cases of dementia can be attributed to modifiable risk factors (3). Early identification of those individuals at greater risk for dementia may lead to the implementation of targeted interventions that may alter the course of cognitive decline. The association of frailty would indicate that efforts at screening patients for dementia risk should especially focus on individuals with frailty as the yield is most likely to be higher.
Strengths of this study are the large number of participants receiving medical care at an integrated healthcare system, large number of minorities, data available from electronic health records and the use of validated instruments. Limitations include the low response rate, a predominantly male sample at one VA medical center, whose ethnic, racial, educational, and socio-economic composition may be different from other community settings. The low survey response rate is in line with previous studies in Veteran populations (18). We used several evidence-based strategies to improve response rates including a short questionnaire, a personalized letter of introduction, a self-addressed envelope and a second letter, “reminder” letter for non-respondents (19). However, other effective techniques may consist of prior notifications, monetary incentives, and format changes such as a larger envelopes or double-sided questionnaires (ours was single sided to minimize bulk) (18-20). Additional study limitations include reliance on self-reported levels of physical activity, which is susceptible to recall and response bias, lack of measurement data of potential confounders, and cross-sectional study design where exposure and outcome are concurrently assessed, and the temporal association between exposure and outcome cannot be definitively established.
There are two major clinical implications of this study. First, the possibility that older adults from certain groups may be more likely to be at high risk for dementia, because they may have multiple risk factors, which if not recognized early, could increase the likelihood of developing dementia. Early detection of patients at risk for dementia can lead to early interventions on modifiable factors and improved prognosis (6, 21). Second, this study shows an alternative population-based approach to properly screen individuals for dementia risk in health care settings. This strategy represents an attempt to reach out to individuals at risk for dementia who do not routinely seek medical care. These postal-based strategies extend existing health services by providing awareness, prevention, and screening, for dementia risk to a larger segment of the population.
In conclusion, this study identified a high prevalence of dementia risk in this sample of community dwelling Veterans. Individuals with frailty were at higher risk for dementia. Mailed screening was feasible and convenient and may serve as an alternative, and scalable approach to identify individuals at risk for dementia.
Funding: This material is the result of work supported with resources and the use of facilities at the Miami VA Healthcare System GRECC. The sponsors had no role in the design and conduct of the study; in the collection, analysis, and interpretation of data; in the preparation of the manuscript; or in the review or approval of the manuscript.
Conflict of interest statement: Aakashi Shah, Otoniel Ysea-Hill, Angelica Torres-Morales, Christian J. Gomez, Alejandro Castellanos, and Jorge G. Ruiz declare that they have no known competing financial interests or personal relationships, which have or could be perceived to have influenced the work reported in this article.
Ethics declaration: A protocol of this study was submitted to and approved by Miami VA Healthcare System Institutional Review Board (IRB) and was exempted from informed consent.
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