Frailty Prevalence and Neighborhood Residence in Older Mexican Americans: The San Antonio Longitudinal Study of Aging Sara E. Espinoza, MD*†‡§ and Helen P. Hazuda, PhD†‡
OBJECTIVES: To examine the association between neighborhood residence and frailty prevalence in older Mexican Americans (MAs). DESIGN: Cross-sectional, observational study. SETTING: Socioeconomically and ethnically diverse neighborhoods in San Antonio, Texas. PARTICIPANTS: Community-dwelling older MA adults (aged ≥65) who completed the baseline examination of the San Antonio Longitudinal Study of Aging (SALSA) (1992– 1996) (N = 394). MEASUREMENTS: Subjects were randomly sampled from three types of neighborhoods that varied in ethnic composition and economic environment: barrio (lowincome, exclusively MA), transitional (middle-income, equal proportion MAs and European Americans (EAs)) and suburban (upper-income, predominantly EA). Frailty was classified using the Fried criteria. Frailty odds were estimated according to neighborhood using logistic regression, with the suburban neighborhood as the reference category. Covariates included age, sex, diseases, depressive symptoms, and cognitive function. RESULTS: Frailty prevalence was 15.6% in the barrio, 9.4% in the transitional neighborhood, and 3.5% in the suburbs (P = .01). After adjusting for sociodemographic characteristics and disease covariates, odds of frailty were 4.15 times as high for MAs residing in the barrio as for those residing in the suburbs (P = .03). After adjustment for depression and cognition, this association was no longer significant. Diabetes mellitus and depression accounted for the higher odds of frailty in the barrio. Although odds of frailty in the transitional neighborhood
From the Divisions of *Geriatrics, Gerontology and Palliative Medicine; † Clinical Epidemiology, Department of Medicine; ‡Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio; and §Geriatrics Research, Education and Clinical Center, South Texas Veterans Healthcare System, San Antonio, Texas. Address correspondence to Sara E. Espinoza, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Mail Code 7875, San Antonio, TX 78229. E-mail: [email protected] DOI: 10.1111/jgs.13202
JAGS 63:106–111, 2015 © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society
were 1.95 times as high as those in the suburbs, the difference was not statistically significant. CONCLUSION: The ethnic composition and economic environment of the neighborhoods in which MA older adults reside are strongly associated with their odds of being frail. J Am Geriatr Soc 63:106–111, 2015.
Key words: frailty; neighborhood; Mexican Americans
F
railty is a geriatric syndrome of vulnerability to stressors marked by risk of poor health outcomes, including disability, falls, nursing home placement, and death.1,2 Prior studies have shown that frailty prevalence is higher in ethnic minority groups,3,4 including Mexican Americans (MAs), who are the largest and most rapidly growing ethnic subgroup in the United States.5 Neighborhood residence has been identified as an important factor that contributes to individual health and can affect cognition, affect, and mobility disability.6–8 Recognizing this, Healthy People 2020 has identified the creation of “social and physical environments that promote good health for all” as one of its four overarching goals.9 The association between neighborhood factors and frailty in older adults living in Rotterdam was recently examined, and it was found that residents who reported a strong sense of social cohesion and neighborhood belonging had lower odds of frailty than those who did not.10 A review of frailty prevalence from several studies of community-dwelling older adults found that frailty prevalence varies from 4% to 59.1%, which suggests that it may vary based on differing characteristics of the communities from which individuals were sampled.11 Only one published study has investigated the association between neighborhood and frailty in older MAs.12 It found that older MAs with lower socioeconomic status (SES) living in neighborhoods with a high density of MAs had a lower risk of becoming frail over 2 years than those living in neighborhoods with a lower density of MAs. The present study provides further insights into the
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JAGS
JANUARY 2015–VOL. 63, NO. 1
association between neighborhood and frailty in older MAs, in particular by examining frailty in three types of neighborhoods that vary in MA composition and SES.
METHODS Subjects
FRAILTY AND NEIGHBORHOOD
107
cutpoints have been published previously.3 Cardiovascular Health Study frailty criteria are the presence of five frailty characteristics: walking speed standardized based on median height and sex, grip strength standardized based on body mass index (BMI) and sex, energy expenditure standardized based on sex, exhaustion based on self-report, and weight loss. Frailty was classified as a dichotomous variable. Individuals with fewer than three frailty characteristics were classified as nonfrail, and those with three or more characteristics were classified as frail.
Subjects for the present report were 394 MAs, aged 65 to 80, who participated in the baseline examination (1992– 96) of the San Antonio Longitudinal Study of Aging (SALSA), a community-based study of the disablement process in older MAs and European Americans (EAs). Detailed descriptions of the sampling design and response rates have been published previously.13,14 Briefly, participants were randomly sampled from three types of neighborhoods purposively selected based on census indicators to represent distinct levels of SES and assimilation to the broader society among Mexican Americans: low-income, almost exclusively MA neighborhoods, where a highly traditional MA cultural orientation predominated (barrio); middle-income, ethnically balanced neighborhoods, where upwardly mobile MA families had gradually moved in, and EA families had moved out (transitional); and highincome, predominantly EA neighborhoods, where MAs had largely adopted the cultural orientation of the broader society (suburbs). The SALSA baseline examination was conducted from April 1992 to June 1996 and consisted of a comprehensive home-based assessment conducted in the participant’s home and a performance-based assessment conducted at a clinical research center. The institutional review board of the University of Texas Health Science Center at San Antonio approved the study, and all subjects gave informed consent.
Clinical measures were used to assess diabetes mellitus, hypertension, myocardial infarction, chronic obstructive pulmonary disease, proteinuria, and peripheral arterial disease, as previously described.17 Arthritis, cancer (nonskin), and stroke were assessed according to self-report of physician-diagnosed disease. Comorbidity was calculated as the number of chronic diseases excluding diabetes mellitus, which was considered separately because of prior work demonstrating that it is highly correlated with frailty,18 as well as being a predictor of frailty progression.19
Measures
Depressive symptoms were assessed using the Geriatric Depression Scale.21 A score greater than 10 was considered probable depression.
Covariates Chronic Disease
Cognitive Impairment Cognition was assessed using the Folstein Mini-Mental State Examination. A score of less than 24 was considered mild cognitive impairment.20
Depressive Symptoms
Neighborhood Neighborhoods were classified as described above. The construct of neighborhood captures the context of daily living and quality of life that residents experience in terms of population density; cultural climate; stressors; sense of belonging and protection; availability of consumer goods, including food, clothing, housing, and medical care; and lifestyle. The continuum from barrio to suburbs represents a gradient of increasing SES and increasing cultural and structural assimilation into the broader society for MAs.15
Ethnic Group Ethnic group was classified as MA using a validated, standardized algorithm, which considers parental surnames (maiden name of mother), birthplace of both parents, selfdeclared ethnic identity, and ethnic background of grandparents.16
Frailty Characterization Validated Fried criteria and standardization procedures2 were applied to the SALSA sample; standardized SALSA
Socioeconomic Status Monthly household income and number of years of formal education were assessed according to self-report.
Statistical Analysis Descriptive statistics were used to summarize the data. Differences in participant characteristics were compared according to neighborhood using analysis of variance for continuous variables and the chi-square statistic for categorical variables. Logistic regression analyses were performed to examine the association between neighborhood type and frailty. Only covariates that significantly varied between the three neighborhood types were included as covariates in the logistic regression analyses. Three sequential models were conducted. Model 1 adjusted for sociodemographic factors (age, sex), Model 2 additionally adjusted for disease factors (diabetes mellitus, chronic obstructive pulmonary disease), and Model 3 additionally adjusted for cognitive impairment and depressive symptoms. Analyses were performed using Stata, version 12 (Stata Corp., College Station, TX).
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almost six times as high (odds ratio (OR) = 5.72, 95% confidence interval (CI) = 1.68–19.45), and neither age nor sex was statistically significant. In Model 2, additionally adjusted for diabetes mellitus and chronic obstructive pulmonary disease, the greater odds of frailty in the barrio than in the suburbs remained statistically significant (OR = 4.15, 95% CI = 1.18–14.60, P = .03). Diabetes mellitus was associated with more than 2.5 greater odds of frailty (OR = 2.74, 95% CI = 1.36–5.51, P = .006). In Model 3, after additional adjustment for cognitive impairment and depressive symptoms, barrio was no longer significantly associated with greater odds of frailty than suburban residence (OR = 3.11, 95% CI = 0.83–11.61, P = .84). Probable depression, but not cognitive impairment, was significantly associated with greater odds of frailty (OR = 2.83, 95% CI = 1.33–6.03, P = .007).
RESULTS Sample Characteristics Table 1 shows participant characteristics according to neighborhood residence. As expected, income and education increased across neighborhood type, from barrio to transitional to suburban. The same pattern was observed for diabetes mellitus, with prevalence increasing across neighborhoods from the barrio to the transitional neighborhood to the suburbs such that diabetes mellitus prevalence was almost two times as high in the barrio (37.9%) as in the suburbs (19.8%). Frailty prevalence followed a neighborhood pattern similar to that observed for diabetes mellitus, with frailty prevalence highest in the barrio (15.6%), intermediate in the transitional neighborhood (9.4%), and lowest in the suburban neighborhood (3.5%) (P = .01). Similarly, the prevalence of depression and cognitive impairment decreased from the barrio to suburbs. Prevalence of cognitive impairment decreased from 49.5% to 23.3% to 4.6% across the three neighborhoods (P < .001), and prevalence of probable depression decreased from 32.1% to 21.6% to 8.0% across the three neighborhoods (P < .001). Table 2 shows the logistic regression models for the association between neighborhood residence and frailty. The odds of frailty for barrio versus suburban residence in Model 1, adjusted for sociodemographic factors, were
DISCUSSION In older MAs residing in barrio, transitional, and suburban neighborhoods, the odds of frailty after adjusting for demographic characteristics (age, sex) was more than five times as great for barrio as for suburban residence. Neighborhood differences in prevalence of diabetes mellitus and depressive symptoms largely explained this excess odds of frailty. Cognitive impairment did not have a significant independent effect on frailty prevalence in these analyses.
Table 1. Baseline Characteristics According to Neighborhood in the San Antonio Longitudinal Study of Aging Characteristic
Barrio, n = 218
Transitional, n = 88
Suburbs, n = 88
P-Value for Neighborhood Difference
Age, mean SD (range 65–80) Female, n (%) Education, years, mean SD (range 0–23) Income category, mean SD (range 1–15)a Hypertension, n (%) Myocardial infarction, n (%) Angina pectoris, n (%) Stroke, n (%) Arthritis, n (%) Nonskin cancer, n (%) Diabetes mellitus, n (%) Chronic obstructive pulmonary disease, n (%) Proteinuria, n (%) Peripheral arterial disease, n (%) Number of chronic conditions, mean SD (range 0–6)b Cognitive impairment, n (%)c Probable depression, n (%)d Frailty, n (%)
69.2 3.2 140 (64.2) 6.7 3.8
70.1 3.2 47 (53.4) 9.8 4.0
68.8 3.1 40 (45.5) 13.4 3.3
.02 .007
OBJECTIVES: To examine the association between neighborhood residence and frailty prevalence in older Mexican Americans (MAs). DESIGN: Cross-sectional, observational study. SETTING: Socioeconomically and ethnically diverse neighborhoods in San Antonio, Texas. PARTICIPANTS: Community-dwelling older MA adults (aged ≥65) who completed the baseline examination of the San Antonio Longitudinal Study of Aging (SALSA) (1992– 1996) (N = 394). MEASUREMENTS: Subjects were randomly sampled from three types of neighborhoods that varied in ethnic composition and economic environment: barrio (lowincome, exclusively MA), transitional (middle-income, equal proportion MAs and European Americans (EAs)) and suburban (upper-income, predominantly EA). Frailty was classified using the Fried criteria. Frailty odds were estimated according to neighborhood using logistic regression, with the suburban neighborhood as the reference category. Covariates included age, sex, diseases, depressive symptoms, and cognitive function. RESULTS: Frailty prevalence was 15.6% in the barrio, 9.4% in the transitional neighborhood, and 3.5% in the suburbs (P = .01). After adjusting for sociodemographic characteristics and disease covariates, odds of frailty were 4.15 times as high for MAs residing in the barrio as for those residing in the suburbs (P = .03). After adjustment for depression and cognition, this association was no longer significant. Diabetes mellitus and depression accounted for the higher odds of frailty in the barrio. Although odds of frailty in the transitional neighborhood
From the Divisions of *Geriatrics, Gerontology and Palliative Medicine; † Clinical Epidemiology, Department of Medicine; ‡Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio; and §Geriatrics Research, Education and Clinical Center, South Texas Veterans Healthcare System, San Antonio, Texas. Address correspondence to Sara E. Espinoza, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Mail Code 7875, San Antonio, TX 78229. E-mail: [email protected] DOI: 10.1111/jgs.13202
JAGS 63:106–111, 2015 © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society
were 1.95 times as high as those in the suburbs, the difference was not statistically significant. CONCLUSION: The ethnic composition and economic environment of the neighborhoods in which MA older adults reside are strongly associated with their odds of being frail. J Am Geriatr Soc 63:106–111, 2015.
Key words: frailty; neighborhood; Mexican Americans
F
railty is a geriatric syndrome of vulnerability to stressors marked by risk of poor health outcomes, including disability, falls, nursing home placement, and death.1,2 Prior studies have shown that frailty prevalence is higher in ethnic minority groups,3,4 including Mexican Americans (MAs), who are the largest and most rapidly growing ethnic subgroup in the United States.5 Neighborhood residence has been identified as an important factor that contributes to individual health and can affect cognition, affect, and mobility disability.6–8 Recognizing this, Healthy People 2020 has identified the creation of “social and physical environments that promote good health for all” as one of its four overarching goals.9 The association between neighborhood factors and frailty in older adults living in Rotterdam was recently examined, and it was found that residents who reported a strong sense of social cohesion and neighborhood belonging had lower odds of frailty than those who did not.10 A review of frailty prevalence from several studies of community-dwelling older adults found that frailty prevalence varies from 4% to 59.1%, which suggests that it may vary based on differing characteristics of the communities from which individuals were sampled.11 Only one published study has investigated the association between neighborhood and frailty in older MAs.12 It found that older MAs with lower socioeconomic status (SES) living in neighborhoods with a high density of MAs had a lower risk of becoming frail over 2 years than those living in neighborhoods with a lower density of MAs. The present study provides further insights into the
0002-8614/15/$15.00
JAGS
JANUARY 2015–VOL. 63, NO. 1
association between neighborhood and frailty in older MAs, in particular by examining frailty in three types of neighborhoods that vary in MA composition and SES.
METHODS Subjects
FRAILTY AND NEIGHBORHOOD
107
cutpoints have been published previously.3 Cardiovascular Health Study frailty criteria are the presence of five frailty characteristics: walking speed standardized based on median height and sex, grip strength standardized based on body mass index (BMI) and sex, energy expenditure standardized based on sex, exhaustion based on self-report, and weight loss. Frailty was classified as a dichotomous variable. Individuals with fewer than three frailty characteristics were classified as nonfrail, and those with three or more characteristics were classified as frail.
Subjects for the present report were 394 MAs, aged 65 to 80, who participated in the baseline examination (1992– 96) of the San Antonio Longitudinal Study of Aging (SALSA), a community-based study of the disablement process in older MAs and European Americans (EAs). Detailed descriptions of the sampling design and response rates have been published previously.13,14 Briefly, participants were randomly sampled from three types of neighborhoods purposively selected based on census indicators to represent distinct levels of SES and assimilation to the broader society among Mexican Americans: low-income, almost exclusively MA neighborhoods, where a highly traditional MA cultural orientation predominated (barrio); middle-income, ethnically balanced neighborhoods, where upwardly mobile MA families had gradually moved in, and EA families had moved out (transitional); and highincome, predominantly EA neighborhoods, where MAs had largely adopted the cultural orientation of the broader society (suburbs). The SALSA baseline examination was conducted from April 1992 to June 1996 and consisted of a comprehensive home-based assessment conducted in the participant’s home and a performance-based assessment conducted at a clinical research center. The institutional review board of the University of Texas Health Science Center at San Antonio approved the study, and all subjects gave informed consent.
Clinical measures were used to assess diabetes mellitus, hypertension, myocardial infarction, chronic obstructive pulmonary disease, proteinuria, and peripheral arterial disease, as previously described.17 Arthritis, cancer (nonskin), and stroke were assessed according to self-report of physician-diagnosed disease. Comorbidity was calculated as the number of chronic diseases excluding diabetes mellitus, which was considered separately because of prior work demonstrating that it is highly correlated with frailty,18 as well as being a predictor of frailty progression.19
Measures
Depressive symptoms were assessed using the Geriatric Depression Scale.21 A score greater than 10 was considered probable depression.
Covariates Chronic Disease
Cognitive Impairment Cognition was assessed using the Folstein Mini-Mental State Examination. A score of less than 24 was considered mild cognitive impairment.20
Depressive Symptoms
Neighborhood Neighborhoods were classified as described above. The construct of neighborhood captures the context of daily living and quality of life that residents experience in terms of population density; cultural climate; stressors; sense of belonging and protection; availability of consumer goods, including food, clothing, housing, and medical care; and lifestyle. The continuum from barrio to suburbs represents a gradient of increasing SES and increasing cultural and structural assimilation into the broader society for MAs.15
Ethnic Group Ethnic group was classified as MA using a validated, standardized algorithm, which considers parental surnames (maiden name of mother), birthplace of both parents, selfdeclared ethnic identity, and ethnic background of grandparents.16
Frailty Characterization Validated Fried criteria and standardization procedures2 were applied to the SALSA sample; standardized SALSA
Socioeconomic Status Monthly household income and number of years of formal education were assessed according to self-report.
Statistical Analysis Descriptive statistics were used to summarize the data. Differences in participant characteristics were compared according to neighborhood using analysis of variance for continuous variables and the chi-square statistic for categorical variables. Logistic regression analyses were performed to examine the association between neighborhood type and frailty. Only covariates that significantly varied between the three neighborhood types were included as covariates in the logistic regression analyses. Three sequential models were conducted. Model 1 adjusted for sociodemographic factors (age, sex), Model 2 additionally adjusted for disease factors (diabetes mellitus, chronic obstructive pulmonary disease), and Model 3 additionally adjusted for cognitive impairment and depressive symptoms. Analyses were performed using Stata, version 12 (Stata Corp., College Station, TX).
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almost six times as high (odds ratio (OR) = 5.72, 95% confidence interval (CI) = 1.68–19.45), and neither age nor sex was statistically significant. In Model 2, additionally adjusted for diabetes mellitus and chronic obstructive pulmonary disease, the greater odds of frailty in the barrio than in the suburbs remained statistically significant (OR = 4.15, 95% CI = 1.18–14.60, P = .03). Diabetes mellitus was associated with more than 2.5 greater odds of frailty (OR = 2.74, 95% CI = 1.36–5.51, P = .006). In Model 3, after additional adjustment for cognitive impairment and depressive symptoms, barrio was no longer significantly associated with greater odds of frailty than suburban residence (OR = 3.11, 95% CI = 0.83–11.61, P = .84). Probable depression, but not cognitive impairment, was significantly associated with greater odds of frailty (OR = 2.83, 95% CI = 1.33–6.03, P = .007).
RESULTS Sample Characteristics Table 1 shows participant characteristics according to neighborhood residence. As expected, income and education increased across neighborhood type, from barrio to transitional to suburban. The same pattern was observed for diabetes mellitus, with prevalence increasing across neighborhoods from the barrio to the transitional neighborhood to the suburbs such that diabetes mellitus prevalence was almost two times as high in the barrio (37.9%) as in the suburbs (19.8%). Frailty prevalence followed a neighborhood pattern similar to that observed for diabetes mellitus, with frailty prevalence highest in the barrio (15.6%), intermediate in the transitional neighborhood (9.4%), and lowest in the suburban neighborhood (3.5%) (P = .01). Similarly, the prevalence of depression and cognitive impairment decreased from the barrio to suburbs. Prevalence of cognitive impairment decreased from 49.5% to 23.3% to 4.6% across the three neighborhoods (P < .001), and prevalence of probable depression decreased from 32.1% to 21.6% to 8.0% across the three neighborhoods (P < .001). Table 2 shows the logistic regression models for the association between neighborhood residence and frailty. The odds of frailty for barrio versus suburban residence in Model 1, adjusted for sociodemographic factors, were
DISCUSSION In older MAs residing in barrio, transitional, and suburban neighborhoods, the odds of frailty after adjusting for demographic characteristics (age, sex) was more than five times as great for barrio as for suburban residence. Neighborhood differences in prevalence of diabetes mellitus and depressive symptoms largely explained this excess odds of frailty. Cognitive impairment did not have a significant independent effect on frailty prevalence in these analyses.
Table 1. Baseline Characteristics According to Neighborhood in the San Antonio Longitudinal Study of Aging Characteristic
Barrio, n = 218
Transitional, n = 88
Suburbs, n = 88
P-Value for Neighborhood Difference
Age, mean SD (range 65–80) Female, n (%) Education, years, mean SD (range 0–23) Income category, mean SD (range 1–15)a Hypertension, n (%) Myocardial infarction, n (%) Angina pectoris, n (%) Stroke, n (%) Arthritis, n (%) Nonskin cancer, n (%) Diabetes mellitus, n (%) Chronic obstructive pulmonary disease, n (%) Proteinuria, n (%) Peripheral arterial disease, n (%) Number of chronic conditions, mean SD (range 0–6)b Cognitive impairment, n (%)c Probable depression, n (%)d Frailty, n (%)
69.2 3.2 140 (64.2) 6.7 3.8
70.1 3.2 47 (53.4) 9.8 4.0
68.8 3.1 40 (45.5) 13.4 3.3
.02 .007
