In the general population, advancing into older adulthood is a period when individuals are faced with a unique array of physical, functional, and environmental stressors. This is no different for individuals aging with a traumatic SCI, who are now living an average of 30 to 40 years post-injury (YPI) (Samsa et al. 1993). As more persons survive into their second, third, and even later decades, living with a disability becomes a life-long process for persons with SCI (Hallin et al. 2001). 

Given the evidence in the previous sections of this chapter indicating that SCI represents a model for premature aging in some body systems (e.g. cardiovascular and endocrine, musculoskeletal, immune, and respiratory systems), the physical and functional declines associated with natural aging are likely to present more quickly among individuals with SCI. Such knowledge of these effects of aging however is insufficient for rehabilitation purposes without any indication of how individuals perceive the aging-related changes and how they adapt their lifestyles in response to such changes (Charlifue et al. 2010).

In attempts to gain more perspective, the evaluation of community reintegration and QoL are often used to contextualize the quality of a person’s life.  As a result, a key goal of rehabilitation is to maximize functionality and independence to allow for successful community reintegration and high QoL. QoL describes the well-being and life satisfaction of an individual, and is a multi-factorial construct, which includes but is not limited to, interpersonal relationships and social support, physical and mental health, environmental comfort, and a host of psycho-social factors (Kaplan &Erickson 2000). Community reintegration is an important constructs shown to be predictive of life satisfaction in persons with SCI (e.g., Pierce et al. 1999; Richards et al. 1999; Putzke et al. 2002b; Tonack et al. 2008; Kemp &Bateham 2010). The term community reintegration is used to refer to returning to the mainstream of family and community life, engaging in normal roles and responsibilities, actively contributing to one‟s social groups and of society as a whole (Dijkers 1998). Thus successful reintegration means resuming occupations or activities deemed important to the individual (i.e., self-care, employment, leisure, etc.; Yasui &Berven 2008). The environment (e.g., social, institutional, cultural or physical), can either create barriers or facilitate access to the community at large. Without exception successful reintegration can lead to improved QoL (Anderson 2004).

In the general population, older adults may face limitations with activities of daily living (e.g., Hoyer et al. 1999), and experience functional declines in the physical domain (e.g., Branch &Jette 1983), which can negatively impact community reintegration and QoL. Similarly, both physical and mental health factors influence quality of life in persons with SCI. For instance, issues with poor physical health, secondary health conditions (e.g., pressure ulcers, pain, etc.), depression and stress, and have all been shown to negatively impact on QoL. 

With regards to aging, however, there are some mixed findings in relation to community reintegration and QoL, even within the same studies. For instance, there are some reports that life satisfaction and community reintegration (at least in some domains) improve with years post-SCI (e.g. Zarb et al. 1990; Tonack et al. 2008), whereas older age is associated with poorer community reintegration and quality of life (e.g. Krause &Crewe 1990; Eisenberg &Saltz 1991; Whiteneck et al. 1992; Tonack et al. 2008). 

As well, some reports provide evidence that QoL improves with increasing age (e.g. Pentland et al. 1995; Westgren &Levi, 1998; Dijkers 1999). However, discrepancies with aging and quality of life tend to be more evident in cross-sectional analyses whereas longitudinal studies “mostly show relatively high and stable levels of QoL over long periods of time” (Kemp &Ettelson 2001, p. 119; Savic et al. 2010). As well, these differences may arise due to the use of different instruments, which may not all assess the same underlying QoL construct. 

In this section (see Table 10), twenty-one longitudinal studies and two cross-sectional studies on community reintegration and QoL after SCI are reviewed. 

Table 9: Quality of Life and Community Reintegration

Discussion

Aging is a complex process that not only encompasses biology. Environmental factors also change over time, which may be particularly critical to persons with SCI, because they not only face physical limitations associated with their SCI, but also social and economic changes that result from injury (Krause &Coker 2006). For example, in a series of papers reporting on the same cohort at different time points over a period of 30 years, there were significant improvements with satisfaction with employment and finances over time (Crewe &Krause 1990; Krause 1992; Krause 1998; Krause &Broderick 2005; Krause &Coker 2006), whereas satisfaction with both social and sex lives decreased (Krause 1997; Krause &Broderick 2005; Krause &Coker 2006). Similarly, Bushnik and Charlifue (2005) observed changes related to economics and technology, but not related to SCI or aging per se. For example, letter writing, which probably included emails, increased in the sample over time because home computing had likely become more common. Although not significant, the high percentage of persons who switched to a portable ventilator or pneumobelt from a fixed ventilator may have improved community reintegration for these individuals. As well, the finding that economic self-sufficiency steadily improved with time (e.g. Charlifue &Gerhart 2004a; Krause &Broderick 2005; Krause &Coker 2006) supports Bushnik’s (2002) speculation that increased economic standing may improve community reintegration. In the case of Bushnik’s (2002) sample, improved financial status enabled access to adaptive equipment (e.g. modified van). 

Conversely, level of community reintegration for Charlifue and Gerhart’s (2004a) sample did not significantly change over time, but this may have been due to sample differences between the studies (i.e. high level tetraplegia versus homogeneous impairment groups), and that the time between data collection intervals in the other studies reviewed were further apart. As well, the individuals in Gerhart and Charlifue‟s (2004a) study were at least 20 years post-injury when they entered the study. At 20 years post-injury, it is likely that routines and strategies for community participation have been well-established, and are not likely to dramatically change over 3 year periods. However, an understanding of environmental factors is important for assessing quality of life since there is evidence that an individual‟s adjustment over time is influenced by corresponding environmental changes (Krause &Sternberg 1997). 

With regards to change in activity patterns, Bushnik and Charlifue (2005) attributed the changes to the natural progression of time utilization from external social activities associated with youth (e.g. card games with friends) to other activities not captured by the study (e.g. spending time with family).  Further, the reported declines in activity by the SCI cohorts as they aged (Bushnik’s (2002), Charlifue and Gerhart’s (2004a), and Krause and Broderick’s (2005) might be similar to declines in activity patterns in the general population (Christensen et al. 1996; Bukov et al. 2002).

One of the main strengths of the studies by Krause (1997), Krause and Broderick (2005), and Krause and Coker (2006) is they assessed whether there were any differences between their current sample and those who were lost to follow-up. Based on these analyses, clear survivor effects emerged in both studies as the characteristics of respondents (persons who participated in both data collection periods) at Time 1 were younger, younger at age of SCI-onset, were less years post-injury, had higher levels of education, more likely to have cervical injuries, greater sitting tolerance, and had more social outings than non-respondents (persons who only participated in the first data collection period). These findings highlight that some care should be taken when interpreting the findings from these studies as it may only reflect survivors.

Although having a SCI inevitably does place some form of activity limitation from the onset of injury, aging “may magnify issues of dependency as needs, ability, and limitation change over time” (Charlifue &Lammertse 2001, p. 415). As with the general population (Roy 1986; Gaston-Johansson et al. 1996; Poluri et al. 2005), issues of fatigue and pain can limit the independence of a person with SCI. Fatigue can be defined as an overwhelming sense of tiredness, lack of energy and often a feeling of total exhaustion (Herlofson & Larsen, 2002). Fatigue after SCI is a prevalent issue (Gerhart et al. 1999; McColl et al. 2003; McColl et al. 2004; Fawkes-Kirby et al. 2008). The findings on the associations between age and fatigue after SCI have been somewhat conflicting. For example, one study found that males with SCI reported an increased fatigue with increasing age (Pentland et al., 1995), whereas some have found greater reports of fatigue in younger persons with SCI with short durations of injury (McColl et al. 2003).

Both pain and fatigue have been both found to negatively impact on several domains of function and QoL (Rintala et al. 1998; Ingles et al. 1999; Herlofson &Larsen 2002). As well, there is some evidence of a relationship between fatigue and pain after SCI (Fawkes-Kirby et al. 2008). When examined together, the study by Charlifue and colleagues (1999) and by Putzke and colleagues (2002a) highlight chronological age as a factor that mediates the expression and/or onset of change. In the study by Charlifue et al. (1999), the youngest and oldest group reported no significant changes in fatigue between Time 1 and Time 2. Similarly, in the study by Putzke et al. (2002a) the youngest and oldest group reported the least amount of pain interference between Year 1 and Year 2, however, overall, older individuals were significantly (p<0.01) more likely to report pain in both years than younger individuals with SCI. In terms of the influence of pain and the interference of pain on QoL over time, Putzke et al. (2002a) found that those individuals who experienced increased interference over time had decreased life satisfaction scores, whereas those whose interference subsided had increased life satisfaction. Similarly, Stensman (1994) observed over 5 years that individuals with variable pain experienced fluctuating global QoL, those with constant pain experience consistently low QoL, and those with no or little pain had consistently high or improvements to an initially low QoL over time.

The finding by Charlifue and colleagues (1999) that increasing age is associated with increased fatigue and additional physical assistance is congruent with other studies examining the effects of long-term SCI (e.g. Gerhart et al. 1993; Thompson, 1999; Liem et al. 2004).   A limitation noted by Charlifue et al. (1999) was that their sample was a relatively ‘young’ age (M = 37.1 years), and none having lived with their SCI for more than 20 years (M = 9.3), and may not have been impacted by the aging process to significantly impact overall health and functional status.  However, the consistent findings for increased fatigue between Time 1 and Time 2 do highlight that there is a consistent physical decline occurring.  Charlifue and colleagues (1999) recognized the systematic changes in their sample (i.e., improved health but declining functionality) but attributed them to external factors such as less contact with the healthcare system, funding changes, which lead to fewer participants reporting particular outcomes.  As well, they noted the need for increased physical assistance over time in their sample may have reflected attitude changes in rehabilitation practice where maintaining functionality is preferred over complete physical independence.  Although the strength of the study is its provision of several perspectives to aging with a SCI, an alternative analysis strategy might have helped to provide a more cohesive model of how the factors assessed related to one another.  For instance, the increases in physical assistance between Time 1 and Time 2 were often accompanied with improvements in health but also with increases in fatigue.  Reporting on associations (or lack of) between these variables may have provided additional support for their conclusions. 

The studies reviewed provide some interesting findings regarding living long-term with SCI, but do highlight some of the challenges associated with assessing quality of life in relation to aging. 

The findings appear to provide some conflicting evidence where in some cases QoL/life satisfaction remained stable over time (i.e. Charlifue et al. 1998; Charlifue et al. 1999; Charlifue &Gerhart 2004b; Savic et al. 2010), decreased with time (i.e. Krause 1997; Charlifue et al. 1998), or improved with time (Stensman 1994; Kemp &Krause 1999; Bushnik 2002; Putzke et al. 2002; Bushnik &Charlifue 2005; Krause &Coker 2006; van Koppenhagen et al. 2009; DeVivo &Chen 2011; Kalpakjian et al. 2011; van Leeuwen et al. 2011). The discrepancies in these studies are partly due to theoretical and methodological differences. For instance, the study by Charlifue et al. (1998) was the only study that explicitly provided a theoretical model for assessing life satisfaction. Specifically, Charlifue and colleagues (1998) framed aging with SCI within a global thesis of function, which took into account physical, psychological, and environmental factors. Several studies with lower levels of evidence predicting life satisfaction have used other models that incorporate a variety of domains thought to impact on QoL (i.e. Pierce et al. 1999; Richards et al. 1999; Tonack et al. 2008). Unfortunately, Charlifue et al. (1998) did not provide a clear rationale for including specific predictor variables in their models. A larger theoretical concern is the issue of response shift (also known as recalibration, reprioritization, and reconceptualization; Schwartz &Spangers 2000), which refers to a dynamic process where an individual undergoes simultaneous changes in their internal standards, values, and conceptulizations of QoL in response to health and physical functioning changes (Tate et al. 2002). Ambiguous or paradoxical findings can occur because of differences among people or changes within people regarding internal standards, values, or conceptualization of health-related QoL (Schwartz et al. 2007). As a result, the psychometric properties (e.g. validity and reliability) of measurement tools can be affected (Schwartz et al. 2007). Hence, issues of response shift should be considered when assessing QoL in persons with SCI, and several recommendations are put forth by Schwartz and colleagues (2007) on how to address them. 

In terms of methodological differences, because the samples in each of the studies had different mean ages and YPI it is not surprising that there are discrepancies in reported QoL. However, when examining the QoL results by an aging parameter, YPI for example, a common finding was that regardless of age, individuals with relatively new SCI (i.e.≤5 YPI) are more likely to experience improvements to their QoL (Stensman 1994; Kemp &Krause 1999; Bushnik 2002; Putzke et al. 2002; Bushnik &Charlifue 2005; Krause &Coker 2006; van Koppenhagen et al. 2009; DeVivo &Chen 2011; Kalpakjian et al. 2011; van Leeuwen et al. 2011) than individuals with longer term SCI (i.e. ≥6 YPI). who consistently report high and stable QoL levels (i.e. Charlifue et al. 1998; Charlifue et al. 1999; Charlifue &Gerhart 2004b; Savic et al. 2010). That is, after sustaining a traumatic SCI, the QoL of these individuals may be low and have more room to improve than those individuals with longer term SCI. In fact, Dijkers (2005) notes that the well-being after SCI reaches a plateau at the end of the adjustment period, which is estimated to last from two to five years (Dijkers 2005). Similarly, Whalley-Hammell (2007) reports that after a four year adjustment period, individuals with SCI feel as though as they live a normal life, and have the same problems as everyone else (Whalley-Hammell 2007). In this review, there one study however that observed no changes in QoL among individuals with ≤5 YPI (Mortenson et al. 2010). Mortenson et al. (2010) argued that the individuals may have already adjusted and experienced a response shift prior to the baseline assessment.

Although age of SCI onset does not appear to preclude high QoL, there are likely age related factors that potentially influence QoL. For example, in studies with samples with mean ages in the 20s, individuals were found to have greater improvements in life satisfaction and QoL if they were students, lived independently, had a lower level injury, had overcome past medical problems, and if they had accessible vans for transportation. Among individuals in their 30s, both Putzke et al. (2002) and Stensman (1994) found QoL to be influenced by amount of pain and interference with pain (Putzke et al. 2002; Stensman 1994), and Kalpakjian et al. (2011) found the relationship between life satisfaction and YPI to vary depending on marital status and sex (Kalpakjian et al. 2011).

Furthermore, when considering research design, comparing persons with SCI to control groups will also likely provide a different picture on QoL in different domains. A strength of Kemp and Krause‟s (1999) was the use of an able-bodied, and a disabled (i.e. polio) comparison group when examining issues of QoL after SCI as it provides some context to the extent of some problems for persons post-SCI (i.e. levels of depression). However, the characteristics of the control groups were significantly different to the group with SCI on some key factors. For instance, the able-bodied and polio groups were significantly older (p< 0.01) and had higher levels of education than the group with SCI (p< 0.05). As well, the polio group was comprised mostly of females, had a mean pediatric age of onset, was 50.9 years post-polio, and 90% were Caucasian, whereas the SCI group was comprised of mostly males from culturally diverse backgrounds, and who had an adult age of onset, and were only 14.5 years post-injury. This limitation was addressed in the study, but highlights that the findings should be interpreted with caution since many socio-demographic and historical factors may have influenced levels of depression and life satisfaction. Nonetheless, the finding that persons with SCI have lower QoL compared to the able-bodied population is consistent with other studies that did not meet the chapter‟s inclusion criteria (Kemp &Ettelson 2001). 

Finally, although a couple of studies reported declines in QoL over time (Krause 1997; Charlifue et al. 1998), subsequent papers focusing on the same cohorts at longer lengths of follow-up reported different results. For example, Charlifue et al. (1998) first reported that after 3 years of observation 76% of the sample consistently rated their overall QoL as either good or excellent, but that there were significant decreases in life satisfaction, as measured by the life satisfaction index (LSI), among older individuals, those with <30 YPI and >40 YPI, and those with complete paraplegia (Charlifue et al. 1998). At a follow up thirteen years later, Savic et al. (2010) similarly reported that 76% of the sample consistently reported overall QoL as good or excellent, and that there were significant differences in LSI scores at 6 different time points over the course of 16 years, with the highest life satisfaction reported at the last time point (Savic et al. 2010). Similarly, over two time points 9 years apart, Krause (1997) reported diminished satisfaction related to social and sex lives, as measured by the life situation questionnaire (LSQ)* (Krause 1997). Such lower satisfaction is corroborated in papers by Krause and Broderick (2005), and Krause and Coker (2006) that used observations from the same cohort at different lengths of follow-up (Krause &Broderick 2005; Krause &Coker 2006). However, these two papers in addition to Crewe and Krause (1990), Krause (1992), and Krause (1998), all reported significant increases in satisfaction related to employment among the same cohort over various lengths of time (Crewe &Krause 1990; Krause 1992;Krause 1998). In general, the overall and common finding from studies that followed the same cohorts over time is that global QoL tends to remain high and stable over time but when considering specific areas of QoL, fluctuations exist with some domains increasing in importance (e.g. employment) and other decreasing (e.g. social and sex lives). 

*Note: Krause (1997) used a modified version of the LSQ. Using this version, the authors also observed significant declines in satisfaction related to family relationships, emotional adjustment and control over life.

Conclusion

• There is Level 4 evidence from four longitudinal studies (Bushnik 2002; Bushnik & Charlifue 2005; Krause & Broderick 2005; Krause & Coker 2006) that changes in environmental factors over time (i.e. economics; technology) may influence QoL in persons with SCI rather than the aging process per se.
• There is Level 4 evidence from two longitudinal studies (Charlifue & Gerhart 2004a; Bushnik & Charlifue 2005) that community reintegration declines with age after SCI. However, these changes in community reintegration may be similar as compared to the aging general population.
• There is Level 4 evidence from six longitudinal studies (Crewe & Krause 1990; Krause 1992; Krause 1997; Krause 1998; Krause & Broderick 2005; Krause & Coker 2006) that selected domains of life satisfaction change (i.e. social life and sex life decrease, and employment and finances increase) as one ages with an SCI. It may be that these changes in satisfaction of certain domains are comparable to changes in the general population.
• There is Level 5 evidence from a cross-sectional study (Kemp & Krause 1999) that age of SCI-onset may be an influential factor on life satisfaction.
• There is Level 4 evidence from one longitudinal study (Charlifue & Gerhart 2004b) that previous perceptions of life satisfaction are predictive of later perceptions of life satisfaction.
• There is Level 5 evidence from two cross-sectional studies (Kemp & Krause 1999; Barker et al. 2011) that life satisfaction is lower for persons with SCI compared to the general population.
• There is Level 4 evidence from two longitudinal studies (Stensman 1994; Putzke et al. 2002a) that previous reports of pain interference after SCI, irrespective of age, are predictive of later pain interference.

• There is Level 4 evidence from a longitudinal study (Charlifue et al. 1999) that fatigue and the need for physical assistance increases over time with SCI.

  There is level 4 evidence from ten longitudinal studies that individuals with ≤5 YPI have the potential to improve their QoL (Stensman 1994; Kemp &Krause 1999; Bushnik 2002; Putzke et al. 2002; Bushnik &Charlifue 2005; Krause &Coker 2006; van Koppenhagen et al. 2009; DeVivo &Chen 2011; Kalpakjian et al. 2011; van Leeuwen et al. 2011).

  There is level 4 evidence from four longitudinal studies that individuals with longer term SCI (i.e. ≥6 YPI) consistently report high and stable QoL level (Charlifue et al. 1998; Charlifue et al. 1999; Charlifue & Gerhart 2004b; Savic et al. 2010).

• Selected domains of life satisfaction (i.e. social life and sex life) may decline as one ages with a SCI. Other domains (i.e. employment and finances) may improve as one ages with a SCI. It may be that these changes in satisfaction of certain domains are comparable to changes in the general population.
• Changes in environmental factors over time (i.e. economics; technology) may influence QOL in persons with SCI rather than the aging process per se.
• Community participation may decline with age after SCI. However, these changes in community participation may be similar to the aging general population.
• Fatigue and the need for physical assistance may increase over time with SCI.
• Individuals with new SCI (i.e. ≤5YPI) consistently report improvements to their QOL, whereas individuals with longer term SCI consistently report high and stable QOL over time.
• Age of SCI-onset may be an influential factor on life satisfaction.
• Previous perceptions of life satisfaction may be predictive of later perceptions of life satisfaction.