Aging

Secondary Complications of Multiple Systems

Most individuals with SCI will develop a variety of secondary complications (Jensen et al. 2013). Common complications include pain, bowel and bladder regulation problems, muscle spasms, fatigue, esophageal symptoms, osteoporosis, cardiovascular disease, diabetes, and respiratory complications or infections (Jensen et al. 2013). As secondary health conditions negatively affect community re-integration and quality of life, the influence of the aging process on these conditions is important to consider in their management. While specific conditions have been described in previous sections (e.g. pain, bowel and bladder regulation, genitourinal and gastrointestinal problems, bone, cardiovascular disease and endocrine problems, and respiratory complications) the below section describes studies with general measures of secondary health complications or multiple health conditions, including physical and mental health (e.g. depression, fatigue and spasticity).

In this section, 1 systematic review and 5 longitudinal studies on secondary health complications after SCI are reviewed.

Table 10. Systematic Review of Secondary Health Conditions of Multiple Systems

Author Year; Country Date included in the review Total Sample Size Level of Evidence Type of study Score	Methods	Outcome
Jensen et al. 2013; USA Reviewed published articles from 1986 to 2011 N=92 Methodological quality not assessed Type of study: Systematic Review AMSTAR: 3	Method: Searches of electronic databases for studies published in English from 1986–2011 that provided information regarding the prevalence, course or associations with age and duration of secondary health conditions in human adults (>18 yrs of age) with SCI. No interventions studied. Outcome Measures: frequency or prevalence, severity, time course, and/or age and duration of effects of a health condition. Databases: PubMed, CINAHL, PsycINFO.	The findings show that individuals with SCI experience a number of secondary health conditions, many of which occur at a higher rate than in the AB population. The most common conditions or symptoms are pain, bowel and bladder regulation problems, muscle spasms, fatigue, esophageal symptoms and osteoporosis. A number of these conditions – including cardiovascular disease, diabetes, bone mineral density loss, fatigue and respiratory complications or infections – occur with higher frequency in older individuals or those with longer SCI duration, relative to younger individuals or those with shorter SCI duration. There is a lack of longitudinal research examining the natural course of health conditions in individuals aging with SCI – the findings from limited studies are often inconsistent, with only cardiovascular disease and weight (as measured by BMI) showing increases over time.

In this scoping review that examined the association between age and secondary health complications post SCI, Jensen et al. (2013) report seven key findings (i.e. evidence that is reported in at least two studies): 1) bladder problems are not associated with duration of injury; 2) spasms are not associated with duration of injury; 3) cardiovascular disease is more prevalent in older individuals; 4) diabetes is more prevalent in older individuals; 5) bone mineral density loss is higher in both older individuals and in individuals with longer duration of injury; 6) fatigue is more commonly reported by older individuals; and 7) respiratory complications/infections are more prevalent in older individuals.

The authors concluded that older age and longer SCI duration are associated with more frequent and severe health conditions. These findings support the belief that premature aging may be occurring in individuals with SCI.

The following reviews additional papers studying aging and secondary health complications after SCI.

Table 11. Aging and Secondary Health Complications After SCI

Author Year; Country Score Research Design Total Sample Size	Methods	Outcome
Adriaansen et al. 2016; The Netherlands Level 5 Cross-sectional N=282	Population: 282 participants with SCI acquired between 18-35 years of age and ≥10 YPI, current age 28-65 years; 74% male, 26% female; 3 groups: TSI 10-19 years n=107, TSI 20-29 years n=96, TSI ≥30 years n=79 Age (years), mean (SD): 48.3 (8.9); mean TSI (years): 22.0 (range 16.8-30.3); Cervical 41%, thoracic 53%, lumbar 6%; AIS A 69%, AIS B 14%, AIS C 10%, AIS D 8% Methodology: Random samples of eligible participants were drawn from 8 Dutch rehabilitation centers. Participants completed a self-report questionnaire about secondary health conditions. Outcome Measures: Occurrence of 13 secondary health conditions (SHCs): neuropathic pain, musculoskeletal pain, pressure ulcers, problematic spasticity, autonomic dysreflexia (AD), hypotension, oedema, neurogenic heterotopic ossification (NHO), pneumonia, urinary tract infection (UTI), urinary incontinence, faecal incontinence, constipation; International SCI QoL Basic Data Set; Spinal Cord Independence Measure III (SCIM-III)	The most prevalent SHCs were: musculoskeletal pain (63.5%), edema (38.7%), neuropathic pain (34.1%) and urinary tract infections (33.3%). Only edema showed a significant association with increasing . Musculoskeletal pain was more common in the TSI ≥ 30 years group compared with the TSI 20–29 years group. Edema was more common in the TSI ≥ 30 years group, compared with the TSI 10–19 years group. AD was less common in the TSI 20–29 years and ≥ 30 years group, compared with the TSI 10–19 years group.
January et al. 2014; USA Level 2 Longitudinal N=214	Population: N=214 (133 M, 81 F); mean age at injury (y) = 13.93±4.37 (range 0-18); Duration of injury (y) = 15.05±6.21 (range 5-34) Injury characteristics: Paraplegia (n=90), tetraplegia (n=124); complete (n=151), incomplete (n=60) Work & relationship status: Unemployed (n=70), employed (n=98), student (n=46); married (22.9%), not married (77.1%) Methodology: A survey was given over a period of 2 to 9 years (between 2000-2013) with an annual follow up to investigate the prevalence of depressive symptoms in adults who sustained a SCI before 19 years of age and to explore potential risk factors that may be associated with elevated symptoms. Outcome Measures: Craig Handicap Assessment and Reporting Technique (CHART), Patient Health Questionnaire-9 (PHQ-9), Functional Independence Measure (FIM)	Depression symptoms at initial status were typically minimal but fluctuated significantly over time. Significant predictors of depressive symptoms were: less community participation, incomplete injury, hazardous drinking, bladder incontinence, and pain—however, marriage resulted in decreases in depression scores for individuals. Those who are employed and more independent in the community had significantly fewer depressive symptoms at baseline.
Finnerup et al. 2016; Denmark & Sweden Level 2 Longitudinal N=81	Population: 81 people with SCI (88% M, 12% F); mean age at follow up (y) = 51.8±15.9 (range 21-80); mean TSI (y) = 3.5±0.6 SCI impairment: Complete (30%), incomplete (68%), paraplegia (42%), tetraplegia (56%), Methodology: Adults with traumatic SCI admitted over a 3-year period to two neurosurgical departments underwent clinical examination and were given questionnaires at 3 months after injury (baseline), 6, 12 and 42 months following SCI to examine presence of pain and psychological function. Outcome Measures: Pain intensity and interference within the last 7 days, a global quality of life (QoL) item, the 5-item Mental Health Index (MHI-5) and the 6-item Catastrophizing scale (CSQ-CAT) were used	After 3.5 years, at least one pain problem was reported in 75% of the sample; musculoskeletal pain was present in 66%, neuropathic SCI pain in 49%, at-level pain reported in 30% and below-level pain in 25%. There were significant correlations between the intensity of at- and below-level neuropathic pain at 3.5 years and the intensity of pain at 6 and 12 months (r=0.68 and 0.68 for at-level pain and 0.59 and 0.76 for below-level pain, respectively, P<0.0001); and there was also a significant correlation between the intensity of musculoskeletal pain at 3.5 years and the intensity of musculoskeletal pain at baseline (r=0.40, P>0.001), 6 months (r=0.32, P=0.006) and 12 months (r=0.36, P=0.001). Psychological functioning and QoL increased over time. QoL scores increased less in participants who reported an increase in pain intensity from baseline to the 3.5-year follow-up, and the change in QoL score correlated with the change in pain interference. Neuropathic pain had an onset within the first 12 months and tended to become persistent, whereas musculoskeletal pain more often had a late onset or resolved over time.
Jorgensen et al. 2016; Sweden Level 5 Cross-sectional N=123	Population: 123 participants with SCI (71% M, 29% F), mean age (y)=63±9 (range 50-89), mean YPI=24±12 (range 10-56); Tetraplegia AIS A-C (n=22), paraplegia AIS A-C (n=41), all AIS D (n=60) Methodology: Data was collected from the participants’ medical records, and through structured interviews and assessments in their homes to describe secondary health conditions, activity limitations, and life satisfaction in older adults with long-term SCI and to investigate how sociodemographics, injury characteristics, and secondary health conditions are associated with their activity limitations and life satisfaction. Outcome Measures: Bowel and bladder function, nociceptive and neuropathic pain, spasticity, the Spinal Cord Independence Measure, third version, and the Satisfaction With Life Scale.	Bowel-related and bladder-related problems were reported by 32% and 44%, respectively. 66% reported moderate or severe nociceptive and/or neuropathic pain, and 44% reported spasticity. Participants who reported moderate or severe neuropathic pain were older at injury, had a shorter time since injury, and were less likely to be vocationally active compared with those reporting no or mild neuropathic pain. Activity limitations were moderate where injury characteristics and spasticity explained 68% of the variance. Participants who had a partner and/or were working full-time or part-time rated their life satisfaction significantly greater, as did those reporting voluntary bowel function, and/or voluntary voiding.
Murray et al. 2016; USA Level 5 Cross-sectional N=187	Population: 187 people with SCI (62% M); mean age (y)=34.3±7.4 (range 19-52); mean age at injury (y)=14.1±4.5 (range 0-19); mean TSI (y)= 20.2±8.5 (range 1-45); tetraplegia (56.1%), paraplegia (43.9%) Methodology: Participants who sustained an SCI before 19 years of age and received care at the Shriner’s Hospital for Children, but who were ≥19 years old during the study period completed interviews to determine medical and psychological correlates of pain in adults with pediatric-onset SCI. Outcome Measures: Beck Anxiety Inventory, Patient Health Questionnaire-9, pain intensity scale (11-point NRS)	Longer duration of injury was significantly associated with longer pain duration. Adults with pediatric-onset tetraplegia experienced greater sleep interference due to pain compared with individuals with paraplegia. A significantly higher percentage of participants with tetraplegia reported pain in their head or neck compared with individuals with paraplegia. In addition, a higher percentage of individuals with paraplegia reported pain in their hand/wrist (32.9% paraplegia, 9.5% tetraplegia) and back compared with those with tetraplegia (67.1% paraplegia, 41.9% tetraplegia). There were no group differences in pain in the chest/abdomen, shoulder, arm/elbow and lower extremities.
Smith et al. 2016; USA Level 2 Longitudinal N_total=1594	Population: 1594 participants (64% F) that included people with SCI (n=414), MD (n=282), MS (n=509), and PPS (n=389); Mean age (y)=56.0±12.9 (range 20-94); mean disability duration (y)=15.3±10.5 Methodology: Survey questions were sent out to assess demographics and self-reported diagnosis of chronic comorbid medical conditions (CCMC) twice, 3.5 years (T1 and T2) apart, to study the incidence, prevalence, age of onset and predictors of five chronic conditions in a sample of adults with long-term physical disabilities (MS, MD, PSS, or SCI). Outcome Measures: Self-reported diagnosis of 5 CCMC’s: coronary heart disease, hypertension, arthritis, diabetes and cancer, and health behaviors (alcohol use, smoking, physical activity).	Arthritis was the most commonly reported new condition, making up 40% of all newly reported conditions. 170/1034 who did not report arthritis at TI reported having it at T2, suggesting an incidence rate of 16% in the sample during the 3.5-year study period. The average age of those reporting new onset of arthritis during the study period was 61 years at T2. Hypertension was the second most commonly reported new onset condition (22% of all newly reported conditions). 92/984 who did not report hypertension at TI reported it at T2 (new incidence rate of 9%). The average age at T2 for individuals reporting a new onset of hypertension was 59. Cancer was the third most common new diagnosis, and made up 21% of all newly reported diagnoses. 89/1371 who did not report a history of cancer at T1 reported it at T2 (7% new incidence rate, with an average age of 65 at T2). Participants who were between the ages of 56 and 65 at T2 were significantly more likely than those who were younger or older to report a new incidence of coronary heart disease or cancer within the last 3.5 years of the study.
Yeh et al. 2016; Taiwan Level 2 Longitudinal N_SCI=10,125 N_control=10,125	Population: 10,125 people with SCI (50% F): mean age (y)=56.3±17.8 (range 20-90) Methodology: A total of 10,125 people with at least 2 ambulatory visits with a diagnosis of SCI in 2001 were enrolled in the SCI group. The non-SCI group comprised 10,125 propensity score-matched (age, gender etc) people without SCI. The median follow-up time was 30.4 months to investigate whether people with SCI are at an increased risk of developing Parkinson’s disease (PD)	For the SCI group, a total of 99 (0.98%) PD cases occurred during 24,113.8 person-years of follow-up, resulting in an incidence rate of 4.10 per 1000 person-years. For the non-SCI group, 59 (0.58%) PD cases occurred during 23,984.7 person-years of follow-up, giving an incidence rate of 2.4 per 1000 person-years. The PD-free survival rate of the SCI group was significantly lower than that of the non-SCI group The HR of PD for the SCI group was 1.39 within the first year of follow-up and was 2.05 after the first year of follow-up. The results show that the association between SCI and PD was more prominent after the first year of follow-up.
Lin et al. 2015; Taiwan Level 2 Longitudinal N_SCI=11 913 N_control=59 565	Population: 11,913 persons with SCI (48.8% F): mean age (y)=56.0±17.9 (range 20-90) Methodology: The SCI group consisted of individuals who had received a diagnosis of SCI in ambulatory medical care between January 1, 2001 and December 31, 2001. For every SCI subject, there were 5 propensity score-matched non-SCI controls to determine whether patients with SCI are at a higher risk for developing multiple sclerosis (MS) after a median follow-up time of 30.6 months.	SCI patients had an 8.33-fold higher risk of MS, compared with non-SCI participants. Of the 11,913 patients with SCI, 5 developed MS during 28,424.2 person-years of follow-up, giving an incidence rate of 17.60 per 100,000 person-years. Of the 59,565 participants in the non-SCI group, 4 developed MS during 141,828.7 person-years of follow-up, giving an incidence rate of 2.82 per 100,000 person-years. SCI group had a higher prevalence of the pre-existing medical comorbidities diabetes, hypertension, and hyperlipidemia than the non-SCI group.
Saunders et al. 2015; USA Level 5 Cross-sectional N=1678	Population: 1678 people with SCI (74% M); mean age (y)=48.4±13.3, mean YPI=15.9±9.9; high tetraplegia (<10%), low tetraplegia (25.4%), paraplegia (33.6%), 31.2% ambulatory regardless of injury level Methodology: Mail-in surveys were distributed to perspective participants recruited from a large specialty rehab hospital to assess the lifetime prevalence of 7 chronic health conditions (CHCs) among a cohort of adults with traumatic SCI. Outcome Measures: CHCs measured using questions from Behavioral Risk Factor Surveillance System (BRFSS) for diabetes, heart attack, angina/coronary artery disease, stroke, hypertension, high blood cholesterol, or cancer	Although the prevalence of CHCs significantly increased with increasing age, only hypertension and cancer were significantly associated with years post-injury. High cholesterol levels appeared to be inversely related to years post-injury, but generally increased with each increasing age group.
Chung et al. 2014; Taiwan Level 2 Longitudinal N_SCI=47,916 N_control= 191,664	Population: A total of 47,916 SCI patients (62.7% men, mean age of 50.0 y) and 191,664 controls were followed for 308,266 and 1,341,169 person-years, respectively. 51% were younger than 50 years old, 21.6% were between 50-65, and 27.4% were older than 65. Methodology: The entire hospitalized population in Taiwan for the 1998–2008 period was studied, with a follow-up period extending to the end of 2010. SCI patients were identified using the Taiwan National Health Insurance Research Database (NHIRD) to assess the risks of deep vein thrombosis (DVT), pulmonary thromboembolism (PE), and other comorbidites. Outcome Measures: Risk of DVT and PE, comorbidities: atrial fibrillation, hypertension, diabetes, hyperlipidemia, cerebrovascular accident, congestive heart failure, lower leg fracture/surgery, cancer.	The SCI cohort was more likely to have atrial fibrillation, hypertension, diabetes, hyperlipidemia, CVA, congestive heart failure, lower leg fracture or surgery, and cancer compared with the non-SCI cohort. People with SCI had a 2.46-fold and 1.57-fold increased risk of developing DVT and PE, respectively, compared with that of the general population. The highest risk of DVT and PE occurred within 3 months after an SCI occurred (HR: 16.9 and 3.64, respectively). The adjusted Hazard Ratio of DVT and PE rose markedly with increasing age. The adjusted Hazard Ratio of DVT was highest among C-spine SCI patients, and the adjusted HR of PE was highest among T-spine SCI patients.
Hwang et al. 2014; USA Level 2 Longitudinal N=351	Population: 351 participants with SCI (226 M, 125 F); at initial interview: mean age (y) = 26.7; mean duration of injury (y) = 12.9; mean age at injury (y) = 13.8 (range 0-18) C1-4 ABC (14.8%), C5-8 ABC (35.9%), T1-S5 ABC (38.7%), AIS D (9.7%) Methodology: To determine longitudinal changes in the occurrence of medical complications in adults with pediatric-onset SCI, participants who sustained an SCI before 19 and who were ≥23 years during the study period were followed annually between 1996 and 2011 through interviews. Outcome Measures: A total of 1793 interviews were conducted. Generalized estimating equation (GEE) models were used to obtain the odds ratio (OR) of having a medical complication over time.	Severe UTIs and spasticity had significantly increased risk of occurrence over time in the C1-4 ABC group. AD and pneumonia/respiratory failure had increased risk of occurrence over time in the C1-4 ABC and C5-8 ABC groups. Hypertension/cardiac disease had a significantly increased occurrence risk in the C1-4 ABC and T1-S5 ABC groups. Activity limiting-shoulder pain was found to have increased odds of occurrence over time in all impairment groups. . The odds of AD and spasticity decreased with time in the T1-S5 ABC group, and the risk of occurrence of UTI, pressure ulcers, urolithiasis, spasticity, and bowel accidents were found to decrease over time in those with AIS D injury.
Molton et al. 2014; USA Level 5 Cross-sectional N_total=521 N_SCI=239	Population: Younger aged (61 M, 87 F): 87 people with SCI and 61 people with MS; years since onset=10.6±6.6; Middle aged (120 M, 189 F): 127 people with SCI and 182 people with MS; years since onset=17.4±9.9; Older aged (31 M, 33 F): 25 people with SCI and 39 people with MS; years since onset=22.7±13.0 Methodology: Individuals with either MS or SCI experiencing chronic pain were recruited through disability specific registries at the University of Washington and given surveys to complete. Outcome Measures: Pain severity (11-point NRS), Patient Reported Outcomes Measurement Information System (PROMIS), Pain Interference Short Form (PRO-PI-SF), Patient Health Questionnaire-9 (PHQ-9), Primary Care Evaluation of Mental Disorders (PRIME-MD)	Pain severity significantly predicted depression and pain-related interference with activities, and pain- related interference with activities significantly predicted depression. Pain-related interference significantly mediated the relationship between pain severity and depression for younger aged, middle-aged, and older aged individuals with MS and SCI. This means that pain severity was no longer a significant predictor of depression after controlling for the interference in activities caused by pain.
Molton et al. 2014; USA Level 5 evidence Cross-sectional N_total=1862 N_SCI=492	Population: 340 people with MD (42.1% M), mean age (y)=53.2 (range 20-89); mean years since diagnosis=14.7±11.5 584 people with MS(17.5% M), mean age (y)=54.5 (range 21-84); mean years since diagnosis=15.3±10.1 446 people with PPS (24.7% M), mean age (y)=67.2 (range 41-94), mean years since diagnosis=16.1±10 492 with SCI (66.7% M), mean age (y)=50.0 (range 21-88), mean years since diagnosis=16.0±10.9; cervical (49.2%), thoracic (47.8%), lumbar (16.1%), sacral (1.4%) Methodology: Participants living with MS, SCI, MD, or PPS were recruited and completed an ongoing longitudinal survey to test a conceptual model of SHCs, age, and function in persons aging with long-term physical disabilities.	Increasing age was associated with greater Physical SHCs, greater functional impairments, and greater frequency of CMCs The functional impairments factor was significantly associated with CMCs, Physical SHCs, Psychosocial SHCs, and Pain, and individuals over age 65 years reported the greatest levels of functional impairments compared to other age groups. Individuals in the middle-aged group (i.e., those between 45 and 65 years) reported higher pain and more Psychosocial SHCs than did either younger or older adults. Being over age 65 years was associated with lower levels of Psychosocial SHCs. Being younger than 45 years did not show a statistically significant difference from the other groups.
Molton et al. 2014; USA Level 5 Cross-sectional w/ AB N_total=910	Population: 910 total participants with disabilities; mean age (y)=53.3; mean time living with disability (y)=15.2 239 people with SCI. Methodology: Participants living with SCI, MS, PPS, or MD were mailed a survey asking them to describe rates of pain and pain interference. Outcome Measures: Patient Reported Outcomes Measurement Information System (PROMIS): pain severity, pain interference, other secondary symptoms (eg. Fatigue, physical function, mobility, depression, sleep) and health conditions (eg. Recent relapse, skin problems, UTI)	In SCI, self-reported levels of pain interference were higher than the national mean from young adulthood through middle age. People with SCI reported similar levels of pain interference throughout younger and middle adulthood (35 to 44, 45 to 54, and 55 to 64). Individuals from older cohorts reported levels of pain that were slightly lower than their middle-aged counterparts. Differences from national PROMIS data were not significant over the age of 75, but the small sample size of individuals with SCI in this age band made results more difficult to interpret.
Ullrich et al. 2013; USA Level 3 Case-control Level 2 N=286	Population: 286 veterans with SCI (97% male): Age (yrs): mean 53; Duration of injury (yrs): mean 17; Type of SCI: 49% paraplegia, 38% low tetraplegia, 13% high tetraplegia; 46% complete. Methodology: 3 standardized annual psychological evaluations given to participants were reviewed. Administrative databases were used to collect SCI specialty care utilization data. Participants were categorized as having elevated pain, elevated depression, both elevated pain and depression, or neither elevated, using cut-off scores on the pain and depression scales. Outcome Measures: Center for Epidemiological Studies Depression Scale (CES-D), Numerical Rating Scale (NRS) for pain, medical comorbidities, SCI specialty care utilization.	20% of the sample showed both elevated pain and depression at Year 1. 59% of participants had either elevated pain or depression or both at Year 1. Depression scores improved over 3 years, but persons with elevated pain and depression showed less improvement on depression scores than did persons with depression alone. Persons with pain and depression tended to utilize more SCI specialty care (number of SCI outpatient visits, number of psychologist visits, inpatient admissions).
Pershouse et al. 2012; Australia Longitudinal Level 2 N=270	Population: 270 persons with traumatic SCI (81% male); mean (SD) age in yrs: 43.3(11.4), range 20-76; mean (SD) age at injury in yrs: 27.3(9.7). Methodology: Data were collected via telephone interviews and written questionnaires annually over 5 years, between 2004 and 2008, across 6 strata comprising participants grouped according to time since injury (<5y, 5–9y, 10–14y, 15–19y, 20–24y, ³25y). Outcome Measures: Secondary Conditions Surveillance Instrument (SCSI)	There was a significant increase in secondary conditions with increasing time since injury.
Saunders et al. 2012; USA Prospective longitudinal Level 2 N=801	Population: 801 adults with traumatic SCI; mean (SD) age in yrs at Time 1 of survey: 44.8(13.8); mean (SD) YPI in yrs at Time 2: 23(10.6). Methodology: There were 2 data collection time points: the first between 2002 and 2004 (Time 1) and second between 2007 and 2009 (Time 2). There were 1543 participants at Time 1 and of those, 993 participated at Time 2; Using information from participants who had valid depression scores at both time points (n=801), change in probable major depression (PMD) status was assessed between the two time points. Outcome Measures: Older Adult Health and Mood Questionnaire (OAHMQ).	22.1% of participants had probable major depression (PMD) at Time 1 and 20.2% at Time 2. Of those who had PMD at Time 1, 55.7% still had PMD at Time 2. Demographic factors (race-gender, age, time since injury) and health behaviours (pain medication use, hours out of bed, days out of the house, exercise) were significantly associated with PMD over time. Socio-economic factors (income, education) were significantly related to depression but were not significant after controlling for behavioural factors.
Hitzig et al. 2010; Canada Longitudinal Level 2 N=344	Population: 344 participants with SCI (293M 51F); 62 incomplete tetraplegia, 81 complete tetraplegia, 92 incomplete paraplegia, 109 complete paraplegia; age range 24-86 yrs; YPI 7-58. Treatment: AT Jousse Long-Term Follow-Up Questionnaire administered over the telephone during 1995-1997 (time 1) and 2003-2004 (time 2). Data collected on socio-demographics, mortality, impairment, health status, secondary health concerns and mobility. Outcome Measures: Chi square analyses, dependent samples t-test.	Secondary health conditions (spasticity, pressure ulcers, bladder infections, kidney problems, cardiac problems, high blood pressure, respiratory complications, arthritis/joint pain, chronic pain, and psychological stress) increased significantly over time except for bowel problems, which decreased. Mean health status at Time 1 decreased significantly by Time 2.
Charlifue et al. 1999; USA Longitudinal Level 2 N enrolled=439 N final=315	Population: 315 individuals with SCI, mean(SD) age 37.1(0.6) yrs, mean(SD) YPI 9.3(0.2). Methodology: Participants studied initially at their 5^th, 10^th, and 15^th anniversaries post-injury and subsequently 5 yrs later at their 10^th, 15^th, and 20^th anniversaries post-injury. Outcome Measures: Physical and psychosocial status.	Para AIS ABC group reported significantly more fatigue between Time 1 and 2. Tetra AIS ABC group reported an increase in the need for physical assistance but had fewer reports of constipation, bladder stones and bleeding.
Charlifue et al. 1999; USA Longitudinal Level 2 N enrolled=439 N final=315	Population: 315 individuals with SCI, mean(SD) age 37.1(0.6) yrs, mean(SD) YPI 9.3(0.2). Methodology: Participants studied initially at their 5^th, 10^th, and 15^th anniversaries post-injury and subsequently 5 yrs later at their 10^th, 15^th, and 20^th anniversaries post-injury. Outcome Measures: Physical and psychosocial status.	Between time 1 and time 2, self-reports of constipation, bladder stones, rectal bleeding, and personal well-being scores decreased (indicating an increase in well-being). Participants also reported requiring more physical assistance. Para AIS ABC group reported significantly more fatigue between Time 1 and 2. Tetra AIS ABC group reported an increase in the need for physical assistance but had fewer reports of constipation, bladder stones and bleeding.

Discussion

Premature aging with a number of different organ systems appears to lead to the higher prevalence of a number of secondary health conditions compared to the normative population (Jensen et al. 2013). Of concern is that more medical attention is required over time to address these secondary health complications (Krause et al. 2013). As with the general population (Roy & Thomas 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 duration 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 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 relatively ‘young’ (M= 37.1 years), and none having lived with their SCI for more than 20 years (M= 9.3), and may not have aged enough to significantly affect 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.

Conclusion

There is Level 3 evidence (Jensen et al. 2013) from a scoping review that cardiovascular disease, diabetes, bone mineral density loss, fatigue and respiratory complications or infections occur with higher frequency in older individuals or those with longer SCI duration, relative to younger individuals or those with shorter SCI duration.

There is Level 4 evidence (Ullrich et al. 2013) from one longitudinal study that co-occurrence of pain and depression is common among persons who have lived with SCI for many years and remains stable over time. There is also evidence that comorbid pain and depression are associated with higher severity of conditions, more persistent conditions over time, and more utilization of SCI specialty health-care services.

There is Level 4 evidence (Hitzig et al. 2010; Pershouse et al. 2012) that secondary health complications increase over time in persons with SCI, (with the exception of bowel problems, which decrease).

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.

Fatigue and the need for physical assistance may increase over time with SCI.

The number of secondary health complications increase with more years post injury.

The incidence and severity of UTIs decrease over time in persons with SCI and prevalence of pressure sores remain stable.

The co-occurrence of pain and depression is common in persons who have lived with SCI for many years.