Sonya R. Miller, MD; Reece O. Rahman, PhD; Pamela Dixon, PhD; Martin Forchheimer, MMP; Denise G. Tate, PhD; and Tanya Yacynych

Abstract
Objective: To analyze differences in, and correlates of, global quality of life (QOL) and health related QOL (HRQOL) between minority and Caucasian individuals with spinal cord injury (SCI) as measured by the Satisfaction with Life Scale (SWLS), and the Medical Outcome Study Short-Form Health Survey (SF-12).
Design: Retrospective, correlational/predictive study using cross-sectional and longitudinal data from the National Model Spinal Cord Injury System Centers.
Results: Minorities endorsed lower satisfaction with life and health-related QOL as compared to Caucasians. Caucasians with more than a high school diploma reported greater physical HRQOL than minorities with similar education.
Conclusion: The influence of race seems to diminish in importance when considered within the context of other variables such as time since injury and societal participation. This study contributes to the literature by demonstrating that while QOL variables are lower for minorities compared to Caucasians, similar factors influence QOL for both minorities and Caucasians.

Keywords: minority; quality of life; spinal cord injury; well-being

Introduction
     Health is no longer defined as merely the absence of disease or pathology, be it physical or psychological (World Health Organization, 2002). In recent years, there has been a growing effort to evaluate the health of an individual more globally, incorporating a variety of factors, such as physical functioning, psychological well-being, and social functioning and interaction. In light of these efforts, there has been an increasingly growing interest in the assessment and evaluation of an individual’s subjective quality of life (QOL), or well-being. A number of broadly defined domains are often grouped together under the umbrella term of QOL. These include: self-perceptions of general physical health, psychological and emotional well-being, successful and rewarding inter-personal relationships, sexual relationships, and spirituality, as well as societal involvement and participation (Renwick & Brown, 1996; Schumaker, Anderson, & Czajikowski, 1990). QOL has thus become a key criterion for assessing the success of rehabilitation across medical populations (Chase, Butt, Hulse, & Johnson, 1996). This is particularly true in the assessment in the rehabilitation of individuals with spinal cord injury (SCI), the population of interest in the current study.
     Given that the field of study concerning QOL is in its relative infancy, there is a paucity of research addressing QOL in minority SCI individuals. Nevertheless, there is an emergent literature that suggests differences in levels of QOL variables existing between minority and Caucasian SCI individuals. For instance, minorities have been observed to report lower levels of QOL as measured by the Global Satisfaction Index and the Living Circumstances Scale, as well as on measures of career opportunities and finances (Krause, 1998). Minorities are less likely to be gainfully employed post-injury, barring differences in educational level (Krause & Anson, 1997; Krause, Kewman, DeVivo, et al., 1999; Krause, Sternberg, Maides, & Lottes, 1998), and are more likely to report elevated levels of post-injury depression (Kemp, Krause, & Adkins, 1999; Krause, Kemp, & Coker, 2000), than are their Caucasian counterparts.
     The specific etiology of these observed differences in QOL remains uncertain. There are a number of factors that necessitate further evaluation in terms of their potential contributory effects concerning these differences. The first of these involve the innumerable sociocultural and ethnic differences between Caucasians and minorities. The need for systematic consideration of ethnic diversity and multicultural issues has been noted in terms of general rehabilitation (Rosenthal et al., 1996; Saravanan, Manigandan, Macaden, Tharion, & Bhattacharji, 2001) and vocational rehabilitation (Leal, Leung, Martin, & Harrison, 1988), as well as within the intricate relationships existing within behavioral health, as effected by various bio-psychosocial mechanisms (Anderson, 1995). Another consideration specific to the SCI populations concerns the etiology of the injury. At present, motor vehicle accidents and violence such as gun shot wounds, are the two most common etiologies of SCI. Violence, however, is on the rise having accounted for 13.9% of SCI injuries between 1973-1977 but being responsible for 21.8% of SCI injuries between 1994-1998 (Nobunaga, Go, & Karunas, 1999). Minorities have been found to be overrepresented among victims of violence and underrepresented in motor vehicle accidents (Farmer, Vaccaro, Balderston, Albert, & Cotler, 1998; Nobunaga et al., 1999; Waters & Adkins, 1997).
     It is thus the purpose of this paper to examine minority and Caucasian SCI groups independently in order to investigate differences in patterns of correlates or predictors of QOL and societal participation variables, and the etiology of any resultant observed differences.

Correlates of QOL
     The literature reviewing the predictors and correlates of QOL includes variables that can be placed in the following categories: a) medical and injury-related variables; b) education and employment variables; c) social relationship related variables; and d) community integration variables. Much of the literature covering potential factors associated with QOL does not emphasize differences according to minority status.
Medical and Injury-Related Variables
     Djikers (1999) found that the greater the number of years since the onset of injury, the greater the individual’s QOL as assessed via the Satisfaction with Life Scale (SWLS). Other medical correlates with life satisfaction, as reported by Djikers (1999), include fewer hospitalizations, fewer pressure sores, and lower levels of neurological impairment, all of which were associated with higher SWLS scores. Fuhrer, Rintala, Hart, Clearman, & Young (1992) reported that a positive association has also been observed between life satisfaction and self-assessed health status.
Education and Employment Variables
     A study utilizing the Life Situation Questionnaire–Revised Edition (LSQ-R), to measure subjective well-being in persons with SCI, noted race-related differences in the effects of finances and career opportunities upon QOL (Krause, 1998). The opportunity to learn, acquire skills, and act on interests was found to be of greater importance for minority participants, and was thus predictive of greater life satisfaction. Fundamental opportunities to learn and progress in life were closely related to subjective well-being following a SCI for minority individuals. Perceived control had the strongest positive association with life satisfaction, while lower levels of education were found to be related to lower SWLS scores (Fuhrer et al., 1992). Those persons who held a bachelor’s degree or better had the highest mean SWLS scores.
Social Relationship Related Variables
     Social relationships have been found to be strong determinants of QOL. Djikers (1999) found that SCI individuals who were married reported greater quality of life than those who were not. A positive association was also found between life satisfaction and measures of social support and perceived control over one’s life as measured by the Life Satisfaction Index-A (LSIA-A) (Fuhrer et al., 1992).
Community Integration Variables
     Social relationships exist within the broader category of societal participation, which has been found to be a strong predictor of subjective well-being. For instance, those with lower levels of handicap in the areas of social integration, mobility, and occupation have higher levels of life satisfaction (Fuhrer et al., 1992). In addition to educational level, race/ethnicity has been found to impact handicap, and through it, to influence life satisfaction (Djikers, 1999). In a study utilizing the LSQ-R to measure subjective well-being in individuals with SCI, an overall active and engaging lifestyle was found to be central to subjective well-being (Krause, 1998). Racial/ethnic differences were observed for the following LSQ-R subscales: finances, career opportunities and living circumstances (Krause, 1998).
     Across all of these dimensions, Caucasians had significantly higher scores, reflecting greater satisfaction. They reported having fewer difficulties with income, transportation, and employment, while minorities reported greater difficulties with opportunities to acquire job related skills as well as familial relationships and living circumstances.
Richards et al. (1999) reported that SCI individuals with greater access to their environment reported greater satisfaction with life. The most powerful predictor of access to the environment was the motor Functional Independence Measure (FIM) (Granger, Hamilton, Keith, Zielezy, & Sherwin, 1986). SCI individuals with greater levels of functional independence have greater access to their environment than do those with more severe impairments. The aforementioned study noted that race, source of insurance sponsorship, and self perceived health also exhibited some predictive value. Having private insurance, being male, and having an increased self-perceived health status were all associated with higher environmental access scores as measured by the Craig Handicap Assessment and Reporting Technique (CHART).
Conversely, being African-American or Hispanic was associated with lower levels of environmental access. In general, being healthy, remaining busy, and engaging in activities inside and outside of the home were all associated with increased life satisfaction (Richards et al., 1999). As evidenced by previous research, quality of life outcomes are influenced by a complex set of factors.
     Based upon the aforementioned research it is hypothesized that subjective QOL and satisfaction with life will vary based on race/ethnicity, with lower QOL and satisfaction with life reported in the minority group. It is further hypothesized that the correlates of higher QOL and greater satisfaction with life would differ between minority and Caucasian participants. For example, it is anticipated that education and employment variables will be of greater predictive value for QOL within the minority group as compared to the Caucasian group.

Methods
Subjects
     The information was gleaned from data gathered by the Model Spinal Cord Injury National Database. The study sample (N = 2744) was 74.2% Caucasian, 22% African American, .7% Native American, Eskimo, or Aleut, 1.4% Asian or Pacific Islander, and 1.5% other. Due to the small sample sizes of some of the individual minority groups, non-Caucasian groups were combined to form a single “minority” category. The mean age at time of injury was 31.41 years (SD = 13.55). Subjects were an average of 7.71 (SD = 7.18) years post injury at the time of data collection. While 63.1% of the sample reported having gainful employment at the time of their injury, only 25.1% reported gainful employment at the time of data collection. Table 1 contains differences in demographic variables for each sample group. Sample differences were noted between the two groups, with minority SCI persons being younger, more likely to be male, unemployed, single, and more likely to have less than a high school diploma. No significant differences were noted in neurological status.

Measures
     The measures utilized in this study are part of the National Model Spinal Cord Injury Care System Annual Follow-up Questionnaire.
     Short Form Health Survey – 12 (SF-12). (Ware, Kosinski, & Keller, 1996). The SF-12 is a 12-item instrument, with each item scored on a 5-point Likert type scale, aimed at assessing an individual’s perceived health status. The instrument yields a total score, a physical component score (PCS) and a mental component score (MCS).
     Satisfaction with Life Scale (SWLS). (Diener, Emmons, Larsen, & Griffin, 1985). The SWLS is a 5-item instrument, with each item scored on a 7-point Likert type scale, designed to measure global cognitive judgments of one’s life in terms of life satisfaction.
     Craig Handicap Reporting and Assessment Technique (CHART). (Whiteneck, Charlifue, Gerhart, Overholser, & Richardson, 1992). The CHART is a 27-item questionnaire aimed at providing a simple, objective measure of the degree to which impairments and disabilities result in handicaps in rehabilitation populations. The measure is comprised of five scales:

Physical Independence—the ability to sustain a customarily effective independent existence;

Mobility—the ability for individuals to move about effectively in their surroundings;

Occupation—the ability to occupy time in the manner customary to that person’s sex, age, and culture;

Social Integration—the ability to participate in and maintain customary social relationships; and

Economic Self-Sufficiency––the ability to sustain customary socio-economic activity and independence.

Data Analyses
     This was a retrospective study. Bivariate and hierarchical regression analyses, including interaction terms, were performed on the collected data. Hierarchical regression was utilized in order to test the relationship of the various conceptual categories outlined above (medical and injury related variables, education and employment variables, social relationship related variables, and community integration variables), and their respective effects on QOL.
     Preliminary analyses were conducted in order to evaluate the variables that possessed predictive value regarding the specific QOL measure. Only variables that demonstrated said value were included in the final models.

Results
     There are significant group differences on quality of life variables (Table 2). Compared with the Caucasian group, minorities had significantly lower scores on scales measuring overall satisfaction with life (SWLS) [(Mean – 17.89, SD – 7.37) t(1335) = 8.44, p = .0005)], and health-related quality of life including physical, (SF-12 PCS) [(Mean = 367.57, SD = 96.90) t(1298) = 2.51, p < .01)] and mental (SF-12 MCS) [(Mean = 506.94, SD=120.93) t(1145) = 2.86, p =<.01)] components.

     Hierarchical regression analyses, summarized in Tables 3, 4 and 5, were calculated to test the hypotheses that satisfaction with life and health-related quality of life would be lower in the minority group and that the correlates of higher QOL and greater satisfaction with life would differ between minority and Caucasian participants. Predictors of satisfaction with life and quality of life variables were examined by placing them in the following conceptual categories, as discussed in the introduction: medical and injury-related variables; employment-related variables; social relationship variables; and societal participation.
     The sample differences between the two groups in age, gender, employment, marital status and education level were controlled for by including these variables in the models. While there were differences between the minority and Caucasian groups on satisfaction with life and health-related quality of life variables, race failed to add any additional predictive value beyond that of the aforementioned predictors. Predictors of satisfaction with life scores were gender (males scored lower than females), time since injury, social integration, mobility and being employed. The full model accounted for 19.7% (F(4,2631) = 1.93, p = .102) of the variance in life satisfaction. Education was eliminated from the model predicting satisfaction with life due to the extreme multicollinearity between education and employment. Variables that predicted the health-related quality of life physical scores (SF-12 PCS) [Table 4] included age, with older age, time since injury, belonging to the majority group, having no re-hospitalizations in the last year, and having at least a high school diploma, predicting better scores. Additionally, an interaction emerged between race and education greater than high school. Finally, Table 5 reports the findings from the model predicting health-related quality of life mental scores (SF-12 MCS). Significant predictors included gender (males scored higher than females), time since injury, social
integration, and mobility.

Discussion
     Findings provide partial support for the hypotheses. As hypothesized, levels of global satisfaction with life, and both mental and physical HRQOL were lower for minorities than for Caucasians. The second hypothesis, however––that predictors of QOL variables would be different among minorities and Caucasians––was only partially supported. When controlling for sample differences and the moderating variables of our conceptual categories (medical and injury-related variables; employment-related variables; social relationship variables; and societal participation), the influence of race was evident only when predicting the physical component of health-related quality of life. Here, Caucasians with more than a high school diploma had higher physical HRQOL than minorities.
     Thus, while race is clearly a factor in global satisfaction with life and health-related quality of life, the process to these outcomes is complex. The influence of race seems to diminish in importance when considered in the context of other variables such as time since injury and societal participation. Similar to previous findings, this study demonstrated differences in QOL between minorities and Caucasians. This study contributes to the literature by demonstrating that while QOL variables are lower for minorities compared with Caucasians; similar factors influence QOL for both minorities and Caucasians.
     Study limitations should be considered in the interpretation of results. Due to relatively small sample sizes within three of the minority groups, we decided to combine all of the racial/ethnic minority groups to form one “minority” category. The effects of race may be masked by the variety of cultures that comprise the category. Many of the instruments that are currently being used are not culture-free and may fail to properly reflect how minority group members occupy their time; relate to family, friends, and others; and get around in their communities (Dijkers, 1999). The interpretation of the content of these instruments may be different by minorities and Caucasians. Therefore, the extent to which cross-racial outcomes reflect true intrinsic similarities and differences cannot be readily determined, as well as the degree to which these are masked or exaggerated by cultural issues. Another important consideration is that there may be subtle nuances in the nature of the construct of subjective well-being between Caucasian and minority persons with SCI (Farmer et al., 1998). Future research could focus on distinct racial/ethnic groups, focusing on unique, culturally-specific indicators or components of QOL.
Rehabilitation professionals need to be aware of the factors that contribute to decreased QOL among all persons with SCI. Rehabilitation programs, interventions, policies, as well as various types and levels of funding need to be examined in order to insure that adequate attention is paid to QOL issues.

References
Anderson, N. B. (1995). Behavioral and sociological perspectives on ethnicity and health: Introduction to the special issue. Health Psychology, 14, 589-591.

Chase, T., Butt, L. M., Hulse, K. L., & Johnson, K. M. M. (1996). Practical guide to health promotion after spinal cord injury (I. S. Lanig, Ed.). Gaithersburg, MD: Aspen Publishers.

Diener, E., Emmons, R. A., Larson, R. J., & Griffin, S. (1985). The satisfaction with life scale. Journal of Personality Assessment, 49, 71-75.

Dijkers, M. (1999). Correlates of life satisfaction among persons with spinal cord injury. Archives of Physical Medicine and Rehabilitation, 80, 867-876.

Farmer, J. C., Vaccaro, A. R., Balderston, R. A., Albert, T. J., & Cotler, J. (1998). The changing nature of admissions to a spinal cord injury center: Violence on the rise. Journal of Spinal Disorders, 11, 400-403.

Fuhrer, M. J., Rintala, D. H., Hart, K. A., Clearman, R., & Young, M. E. (1992). Relationship of life satisfaction to impairment, disability, and handicap among persons with spinal cord injury living in the community. Archives of Physical Medicine and Rehabilitation, 73, 552-557.

Granger, C. V., Hamilton, B. B., Keith, R. A., Zielezy, M., & Sherwin, E. S. (1986). Advances in functional assessment for medical rehabilitation. Topics in Geriatric Rehabilitation, 1, 59-74.

Kemp, B., Krause, J. S., & Adkins, R. (1999). Depression among African-Americans, Latinos, and Caucasians with spinal cord injury: An exploratory study. Rehabilitation Psychology, 44, 235-247.

Krause, J. S. (1998). Dimensions of subjective well-being after spinal cord injury: An empirical analysis by gender and race/ethnicity. Archives of Physical Medicine and Rehabilitation, 79, 900-909.

Krause, J. S., & Anson, C. A. (1997). Adjustment after spinal cord injury: Relationship to gender and race. Rehabilitation Psychology, 42, 31-46.

Krause, J. S., Kemp, B., & Coker, J. (2000). Depression after spinal cord injury: Relation to gender, ethnicity, aging, and socioeconomic indicators. Archives of Physical Medicine and Rehabilitation, 81, 1099-1109.

Krause, J. S., Kewman, D., DeVivo, M. J., Maynard, F., Coker, J., Roach, M. J., et al. (1999). Employment after spinal cord injury: An analysis of cases from the Model Spinal Cord Injury Systems. Archives of Physical Medicine and Rehabilitation, 80, 1492-1500.

Krause, J. S., Sternberg, M., Maides, J., & Lottes, S. (1998). Employment after spinal cord injury: Differences related to geographic region, gender, and race. Archives of Physical Medicine and Rehabilitation, 79, 615-624.

Leal, A., Leung, P., Martin, W. E., & Harrison, D. (1988). Multicultural aspects of rehabilitation counseling: Issues and challenges. Journal of Applied Rehabilitation Counseling, 19, 3.

Nobunaga, A. I., Go, B. K., & Karunas, R. B. (1999). Recent demographic and injury trends in people served by the model spinal cord injury care systems. Archives of Physical Medicine and Rehabilitation, 80, 1372-1382.

Renwick, R., & Brown, I. (1996). The center for health promotion’s conceptual approach to quality of life: Being, becoming and belonging. In R. Renwick, I. Brown, & M. Nagler (Eds.), Quality of life in health promotion and rehabilitation (pp. 75-86). Thousand Oaks, CA: Sage.

Richards, J. S., Bombardier, C. H., Tate, D., Dijkers, M., Gordon, W., Shewchuk, R., et al. (1999). Access to the environment and life satisfaction after spinal cord injury. Archives of Physical Medicine and Rehabilitation, 80, 1501-1506.

Rosenthal, M., Dijkers, M., Harrison-Felix, C., Nabors, N., Witol, A. D., Young, M. E., et al. (1996). Impact of minority status on functional outcome and community integration following traumatic brain injury. Journal of Head Trauma Rehabilitation, 11, 40-57.

Saravanan, B., Manigandan, C., Macaden, A., Tharion, G., & Bhattacharji, S. (2001). Re-examining the psychology of spinal cord injury: A meaning centered approach from a cultural perspective. Spinal Cord, 39, 323-326.

Schumaker, S., Anderson, R., & Czajikowski, S. (1990). Psychological tests and scales. In B. Spiker (Ed.), Quality of life assessments in clinical trials (pp. 95-113). New York: Raven Press.

Ware, J. E., Kosinski, M., & Keller, S. D. (1996). A 12-item short-form health survey: Construction of scales and preliminary tests of reliability and validity. Medical Care, 34, 220-233.

Waters, R. L., & Adkins, R. H. (1997). Firearm versus motor vehicle related spinal cord injury: Pre-injury factors, injury characteristics, and initial outcome comparisons among ethnically diverse groups. Archives of Physical Medicine and Rehabilitation, 78, 150-155.

Whiteneck, G. G., Charlifue, S. W., Gerhart, K. A., Overholser, J. D., & Richardson, G. N. (1992). Quantifying handicap: A new measure of long-term rehabilitation outcomes. Archives of Physical Medicine and Rehabilitation, 73, 519-526.

World Health Organization (2002). Definition of Health. Available from http://www.who.int/aboutwho/en/definition.html

Sonya R. Miller, MD, is an assistant professor in the Department of Physical Medicine and Rehabilitation, at the University of Michigan.
Reece O. Rahman, PhD, is an assistant professor at the University of Pittsburgh in Johnstown , PA.
Pamela Dixon, PhD, is a lecturer and researcher at the University of Michigan’s Department of Physical Medicine and Rehabilitation.
Martin Forchheimer, MPP, is the director of research at the University of Michigan’s Model SCI Care System and he is the coordinator of a collaborative study led by Craig Hospital in Colorado.
Denise G. Tate, PhD, is a professor at the University of Michigan’s Department of Physical Medicine and Rehabilitation
Tanya Yacynych is an undergraduate research assistant at the University Of Pittsburgh in Johnstown, PA.

HOME

This entry was posted on Thursday, March 8th, 2007 at 2:46 pm and is filed under Psychosocial Process, Consumer Issues, Quality of Life, Secondary Conditions, Psychosocial Adjustment, Research. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.