Constructing and identifying predictors of frailty among homeless adults—A latent variable structural equations model approach

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Abstract

Homeless urbanites are a heterogeneous population with unique health and social service needs. The study examined situational, behavioral, health-related and resource indicators in terms of their direct impact on frailty, hypothesized as a latent variable. Using structural equation modeling (SEM), a model was tested with 150 homeless men and women, ages 40–73, from three homeless day center drop-in sites on Skid Row and one residential drug treatment (RDT) facility that works with homeless parolees and probationers. In bivariate analyses with the latent construct frailty, months homeless (p < 0.01), female gender (p < 0.05), education (p < 0.05), comorbid conditions (p < 0.001), nutrition (p < 0.001), resilience (p < 0.001), health care utilization (p < 0.01), and falls (p < 0.001) were significantly associated with frailty. In the final path model, significant predictors of frailty included educational attainment (p < 0.01), comorbid conditions (p < 0.001), nutrition (p < 0.001), resilience (p < 0.001), and falls (p < 0.01). These findings will serve as a foundation for future nurse-led, community-based initiatives that focus on key predictors of frailty among the homeless and the development of interventions.

Introduction

Frailty, a public health challenge, may be a significant issue among homeless and disenfranchised populations in urban and rural cities across the United States (U.S.). Defined as an accumulation of deficits (Rockwood and Mitnitski, 2007, Rockwood and Mitnitski, 2011) across physical, psychological, and social domains (Gobbens, van Assen, Luijkx, & Schols, 2011), this phenomenon may be a major contributor to disability, morbidity, and premature mortality. For decades, frailty has been written about and characterized; a seminal paper identifies frailty as a clinical syndrome with specific hallmark characteristics (Fried et al., 2001) such as shrinking, weakness, exhaustion, slowness, and low activity. While other authors focus on signs, and disease classifications, often leading to adverse outcomes (Mitnitski, Mogilner, MacKnight, & Rockwood, 2002).

Los Angeles, a large metropolis denoted as the homeless capital of the U.S., faces consistently high rates of homelessness. On any given night, over 40,000 homeless adults are on the streets (Morrison, 2011). Similar to domestic and international aging trends, homeless adults are similarly aging and experts believe will double within the next several decades (Brown, Kiely, Bharel, & Mitchell, 2011; DiMassa, 2008, Kushel, 2012, LAHSA, 2011, Sermons and Henry, 2010). Based on current trends of homelessness in Los Angeles, the population is aging; in particular, data reveal over one third are over 55 years of age (LAHSA, 2011) and frailty may be a significant issue.

Frailty among vulnerable populations has not been studied widely; however, homeless populations may have a lifetime of risk factors for frailty which may encompass poor nutrition (Baggett et al., 2011, Sprake et al., 2013), chronic diseases such as hypertension (Child, Bierer, & Eagle, 1998) and diabetes (Scott et al., 2013), along with the aging of the population (LAHSA, 2011), histories of incarceration (Tejani et al., 2013), gang-related activities and substance abuse which may lead to adverse outcomes.

Previous frailty models have been aptly described and focus on physiological, biological and molecular exploratory frameworks (Bergman et al., 2004, Fried and Walston, 2003). In fact, at the nucleus of many models is a decline in physiological reserve which leads to adverse outcomes (Bergman et al., 2004); models particularly focused on frailty among homeless populations have not been devised. Further, varied measurement instruments are used, along with definitions. One definition identifies frailty as an accumulation of deficits which includes signs, symptoms and disease classifications (Mitnitski et al., 2002); while another indicates frailty is composed of shrinking, weakness, exhaustion, slowness, and low activity (Fried et al., 2001).

Frailty has been studied among community dwelling older adults (Bollwein et al., 2013) in Germany (Saum et al., 2012), Brazil (de Andrade et al., 2013, Vieira et al., 2013), Montreal (Au et al., 2011) and the U.S. (Fried et al., 2001) to name a few. Among older community dwelling adults, frailty prevalence has been found to be approximately 7%; predictors of frailty among community dwelling older adults included being African American, having lower education and income, poorer health, and greater comorbid disease and disability (Fried et al., 2001). Using the same frailty measure, Brown, Kiely, Bharel, and Mitchell (2012) studied geriatric syndromes among homeless adults and found that the prevalence of frailty was 16%. Among older homeless adults, alcohol and drug use problems, having less than a high school education, diabetes and arthritis, and difficulty with activities of daily living was associated with an increased number of geriatric syndromes, one of which was frailty (Brown, Kiely, Bharel, & Mitchell, 2013). Authors contend that homeless populations evidence unique risk factors for geriatric syndromes, one of which is frailty; in particular, those who have one geriatric syndrome should be screened for others, such as cognitive impairment, functional impairment, falls, sensory impairment and urinary continence (Brown, Kiely, Bharel, & Mitchell, 2013). Authors acknowledge that evidence of frailty in homeless populations in general, and as demonstrated more recently among older homeless adults, has further strengthened the case for the need to conduct our study of frailty specifically among the older homeless adult group and to propose interventions which may include screening for geriatric syndromes and clinical case management (Brown, Kiely, Bharel, & Mitchell, 2013).

Thus, the purpose of our study was to test a latent variable, “frailty” which encompasses physical, psychological and social domains and then utilize SEM to assess the relative impact of predictors among a sample of 150 homeless adults in Los Angeles, CA. This study will enable a better understanding of frailty among homeless adults in order to help identify areas for intervention.

Section snippets

Design, sample and site

Cross-sectional data were collected from a sample of 150 homeless men and women in Los Angeles from February to May 2012. This study was approved by the University Human Subjects Protection Committee. Homeless men and women comprised the sample (N = 150; 50% female) and were found eligible if they were: (a) aged 40 or over; (b) free of evidence of acute psychotic hallucinations and psychosis; (c) English-speaking; and (d) homeless. Participants were recruited from three homeless day center drop

Data analysis

Prior to the confirmatory factor analysis (CFA) for the frailty latent construct, a preliminary analysis included a six-pronged approach: (1) selecting variables based on the domains of frailty: physical, psychological and social, (2) determining lack of redundancy between items; (3) a principal components analysis (PCA) to establish what linear components exist within the data (Field, 2009) using IBM Statistical Package for the Social Sciences (SPSS) Version 20 (SPSS, 2012); (4) scanning

Sociodemographics

The average age of the participants was 52.3 years (SD 6.8); the sample is African American (63.3%), followed by Anglo/White/Caucasian (12%), Hispanic/Latino (10.7%), and other groups (14%). The majority of participants was unmarried (48%) or divorced (34.7%) and most completed grades 9–12 (53.3%). About one third of the sample completed some college (32%; table not shown).

PCA

A PCA was conducted to assess the underlying structure for the items hypothesized to compose frailty utilizing orthogonal

Discussion

Guided by the modified FFVP, the purpose of our study was to test a latent variable known as frailty which encompasses physical, psychological and social domains and utilize SEM to assess the relative impact of predictors among a sample of 150 homeless adults in Los Angeles, California. We developed the latent construct, frailty, based upon physical, psychological and social domains which had no conceptual overlap and had high factor loadings. Our findings revealed that education, nutrition,

Conflict of interest

All authors have contributed to the design, analysis and interpretation of the paper, the writing and approval of the final version. All authors will take public responsibility for the content of the paper. The content of this paper has not been published nor is it being considered elsewhere. No possible conflicts of interest exist, there is no supplementary work to the results of the paper and the study was reviewed and approved by the respective institutional review board for human

Acknowledgements

This work was supported by the National Institute of Health (NIH)/Nursing Research (NINR) T32 NR007077, University of California Los Angeles (UCLA) Dissertation Year Fellowship Award, and the University of California, Los Angeles Community Academic Partnership for Research in Aging (L.A. CAPRA) Center NIH Grant 1RC4AG038182-01. We acknowledge the support of Judith Stein, PhD in providing guidance with the analysis. We similarly thank the Los Angeles-based Skid Row homeless participants for

References (71)

  • B. Vellas et al.

    The Mini Nutritional Assessment (MNA) and its use in grading the nutritional state of elderly patients

    Nutrition

    (1999)
  • P. Yu et al.

    Frailty and survival of older Chinese adults in urban and rural areas: Results from the Beijing Longitudinal Study of Aging

    Archives of Gerontology and Geriatrics

    (2012)
  • B.E. Alvarado et al.

    Life course social and health conditions linked to frailty in Latin American older men and women

    Journals of Gerontology. Series A, Biological Sciences and Medical Sciences

    (2008)
  • A. Au et al.

    Frailty markers predicting emergency department visits in a community-dwelling sample of vulnerable seniors in montreal

    Can J Aging

    (2011)
  • T.P. Baggett et al.

    Food insufficiency and health services utilization in a national sample of homeless adults

    Journal of General Internal Medicine

    (2011)
  • P.M. Bentler
    (2006)
  • P.M. Bentler et al.

    Structural equation modeling with small samples: Test statistics

    Multivariate Behavioral Research

    (1999)
  • H. Bergman et al.

    Developing a working framework for understanding frailty

    Gerontologie et societe

    (2004)
  • J. Bollwein et al.

    Dietary quality is related to frailty in community-dwelling older adults

    J Gerontol A Biol Sci Med Sci

    (2013)
  • R.T. Brown et al.

    Geriatric syndromes in older homeless adults

    Journal of General Internal Medicine

    (2012)
  • R.T. Brown et al.

    Factors associated with geriatric syndromes in older homeless adults

    Journal of Health Care for the Poor Underserved

    (2013)
  • R.T. Brown et al.

    Use of acute care services among older homeless adults

    Journal of the American Medical Association (JAMA) Internal Medicine, 1-2

    (2013)
  • F. Cacciatore et al.

    Clinical frailty and long-term mortality in elderly subjects with diabetes

    Acta diabetologica

    (2012)
  • J. Child et al.

    Unexpected factors predict control of hypertension in a hospital-based homeless clinic

    Mount Sinai Journal of Medicine

    (1998)
  • D.E. Crews et al.

    Aging, disability, and frailty: Implications for universal design

    Journal of Physiological Anthropology

    (2006)
  • F.B. de Andrade et al.

    Relationship between oral health and frailty in community-dwelling elderly individuals in Brazil

    Journal of the American Geriatrics Society

    (2013)
  • R. DiMaria-Ghalili et al.

    Mini nutritional assessment – How to try this

    (2008)
  • C. DiMassa

    L.A.’s elderly homeless population is growing

    Los Angeles Times

    (2008)
  • A.P. Field

    Discovering statistics using SPSS

    (2009)
  • J. Fountain et al.

    Unmet drug and alcohol service needs of homeless people in London: A complex issue

    Substance Use and Misuse

    (2003)
  • L.P. Fried et al.

    Frailty and failure to thrive

  • L. Fried et al.

    Frailty in older adults: Evidence for a phenotype

    Journals of Gerontology. Series A, Biological Sciences and Medical Sciences

    (2001)
  • J. Garre-Olmo et al.

    Prevalence of frailty phenotypes and risk of mortality in a community-dwelling elderly cohort

    Age and Ageing

    (2013)
  • R.J. Gobbens et al.

    Testing an integral conceptual model of frailty

    Journal of Advanced Nursing

    (2011)
  • W.B. Goggins et al.

    Frailty index as a measure of biological age in a Chinese population

    Journals of Gerontology. Series A, Biological Sciences and Medical Sciences

    (2005)
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