Aging with spinal cord injury.

Many myths surround aging. One of the most common is the belief that getting older means being ill. Another says that older people are less physically and mentally active. A third common myth is that older people have a poorer quality of life.

These tales arise partly out of our fear of the unknown and partly out of our belief that aging is a wholly negative process. And, aging is not without is negative context. Undeniably, aging is evidence that life is transient and relatively short, proof that we have limited internal resources and defenses against countless external forces -- one of which is time itself. Indeed, aging is not a preventable process; it is something that all humans will encounter. It may occur at different rates and at different ages and in different ways for each person, but it will occur.

Unfortunately, differentiating normal aging from a host of other medical, social, environmental, chemical, physical, and psychological processes is virtually impossible. For example, are heart problems, cancer, or even just changes in the appearance of our skin or in our visual acuity a result of growing older or are they the result of specific environmental or chemical exposures or genetic makeups that have nothing to do with age? Indeed, all are highly interactive, all effect the aging process. How then do we separate aging from these other issues and influences?

If aging is a complex topic, superimposing disability -- like spinal cord injury (SCI) -- only complicates it further. In addition to all of the above "normal" aging-related processes, disability brings its own question, theories, and conceptualizations. In the World Health Organization's conceptualization of disablement,[1] there is impairment -- an abnormality of structure or function, for example, spinal cord damage at the C5 level. There is also disability -- the dependencies and limitations that result from an impairment, such as not being able to walk, to dress, to live independently. There is handicap -- the social barriers that result from impairments and disabilities, like not being able to work, to raise children, to be involved in the community. And, of course, there are complications and secondary disabilities and other issues that come later, after the initial disability. Some are medical, some are physical, and some are psychosocial. All impact and interact with the aging process and illustrate how both the topics of aging and disability are clouded and confused by a plethora of terms, concepts, and issues. In the end, it becomes very difficult to separate normal aging from medical complications and from the initial disability and it own complications.

When are a spinal cord injury survivor's chronic infection, depression, or painful shoulders just part of normal aging? After all, nondisabled people may have these very same problems. When are they a sign or a result of accelerated aging caused by the spinal cord injury? When are they neither and, as some might argue, when are they just coincidental secondary impairments and disabilities -- medical problems that are unrelated to either SCI or to aging? What happens when such problems occur within the context of a long-term SCI survivor's changing living situation -- a divorce, an aging caregiver, a lost job, a changing neighborhood that the survivor no longer feels safe in? As a result of this confusion, are true medical complications or psychosocial concerns -- treatable problems -- being passed off as expected age-related issues? Or, on the other hand, are we vainly struggling to "cure" problems that really are nothing more than normal aging? Are these questions just academic? And, do we care about their answers? To this last we must respond "Yes!" if how we answer affects how we understand long-term spinal cord injury and how interact with and treat the long-term spinal cord injured individual.

Longitudinal Research

Indeed, the issue of aging with a spinal cord injury is a complicated one. We need to approach it scientifically to learn "what's what." Here the concept of longitudinal research becomes important. Studying the same group of people over time helps us to understand the interrelationships of all of the issues described above and, most important, to understand risk factors.

In fact, there has been a fair amount of longitudinal aging research done. Thousands of people have been studied over long periods of time to track changes with age. Three well-known aging studies include the Baltimore,[2] Duke University,[3] and Framingham[4] studies. However, important as these studies have been in expanding our knowledge of physiological aging, the relationship between disease and aging, or of risk factors for later impairments or morbidities, they have not addressed the aging process as if affects people with disabilities, particularly those who have spinal cord injuries. None examines how the normal aging that occurs in a body system impacts the person aging with a superimposed spinal cord injury.

Until very recently, there has been little research particularly designed to study aging in people with spinal cord injuries. One of the difficulties in studying aging in this group is the wise degree of variation that exists; depending on the neurologic level itself or how severe the disability is, or on the age and a range of other characteristics of the survivor and his or her environment, outcomes may be very different.

Thus, research has been needed which could focus on uncovering common variations or risk factors over time. One of the first attempts to conduct such longitudinal research has taken place in Great Britain under the leadership of the Rehabilitation Research and Training Center on Aging with Spinal Cord Injury, Craig Hospital, Englewood, Colorado. That team, funded by both the Centers for Disease Control and Prevention and the U.S. Department of Education's National Institute on Disability and Rehabilitation Research, has been working with two of the world's oldest SCI treatment facilities, both located in England -- the National Spinal Injuries Centre at Stoke Mandeville Hospital, in Aylesbury, and the Regional Spinal Injuries Centre, in Southport -- to track more than 800 individuals with long-term spinal cord injuries.

To date, three phases of the British study have been completed, one in 1990, one in 1993, and one in 1996. Analysis of the third phase is currently underway. People selected for the study had injuries which were traumatic and occurred over 25 years ago. They had to be be between 15 and 55 years old at the time of the injury, thus eliminating children, whose needs are very different from those of adults, and older persons who were already well into the aging process before their injuries occurred. To be eligible for the study, participants had to have lived, at the time of injury, in one of 13 specific counties served by the two hospitals. This was to ensure the most population-based sample possible. Finally, participants also had to have been admitted to one of the two spinal centers within 1 year of injury and had to have survived for at least 1 year following the injury. This was to exclude individuals whose early hospital records may have been less complete or who might not have received state-of-the-art early care and ensure that the research focused on complications, problems, and even deaths that we were related to the aging process rather than to the initial injury itself.

Eight hundred and thirty-four people were identified who met all the selection criteria. As is still typical of spinal cord injury demographics today,[5] there were substantially more men than women -- 87 percent were men. Almost half of the participants -- 42 percent -- had been injured in their late teens and early twenties. The majority, however, were injured between ages 25 and 34. Approximately two-thirds of the participants had paraplegia, while a third had tetraplegia -- a distribution that probably reflects differences in the survival outcomes of several decades ago.

The spinal center medical records were reviewed for all elligible participants to identify a range of variables, most importantly, a history -- via documented ICD9 codes[6] -- of their health and medical issues and complications. British vital statistics and death records also were reviewed to identify those who had died up to the time of the 1990 investigation.

Four hundred and twelve of the original eight hundred and eighty-four people were know to be alive. Three hundred and fifty-two were successfully contacted in 1990 and 282 -- 80 percent -- agreed to participate in an additional, ongoing study. They underwent a physical examination, range of motion, sensory and muscle testing, an electrocardiogram and chest x-ray, complete blood and urinalysis, and vital capacity assessment. They also completed lengthy surveys about their perceived health and health problems, and completed several psychometric instruments designed to quantify well-being, life satisfaction and quality of life. Three years later, 227 of these returned and repeated the examination and evaluation process. This time, measures of depression and perceived stress were added and their spouses were interviewed as well. What follows is an overview of the findings of this comprehensive longitudinal study.

Dates Rates and Causes of Death

Death data were obtained by reviewing medical records and by contacting Great Britain's Office of Population Censuses and Surveys. These reviews established that the British SCI survivors did have a higher death rate than the general population. Twenty-year-olds had a death rate (7.2 per 1,000) that was eight times higher than their 20-year-old nondisabled counterparts (0.9 per 1,000). By age 70, the death rate in the SCI population had increased to 75.1 per 1,000. However, this was now only one and one-half times higher than 70-year-olds in the general population (50.2 per 1,000), indicating a decreasing mortality ratio despite an increasing mortality rate.[7] This decreasing death ratio was noticed both as survivors got older and the longer they were hurt.

Among those of the 834 who had died prior to 1990, problems with the kidneys and genitourinary system were the most frequent causes of death, accounting for just over 24 percent of all the deaths, a proportion substantially greater than in the general population. Cardiovascular-related problems were the second leading cause of mortality, accounting for 23 percent of all of the deaths. Included were heart attacks, strokes, and other heart and circulatory complications. Compared to the general population, death rates for cardiovascular disease tended to be only slightly higher;[7] however, the deaths did appear to be occurring at earlier ages.

Respiratory causes accounted for 14 percent of all deaths and in all age groups the death rate from respiratory illnesses was higher than in the general population.[7] The remaining causes of death -- injuries, cancer, septicemia, and others -- were relatively infrequent.

Between 1990 and 1993 another 15 persons had died. Their causes of death were similar to those of persons who had died prior to 1990 -- cardiovascular disease, pnuemonia, septicemia, cancer, and suicide. This listing is very similar to what is reported by the U.S. National SCI database,[5] for individuals dying 5 or more years after their initial injuries.

The records of these 15 individuals were examined to identify significant differences between them while they were still living and the study participants who had not died. Those who died did not differ with respect to gender, length of injury, or severity of their disability; however, they did consume more alcohol, and those who were smokers had smoked longer -- but not more per day -- than survivors who were current smokers. Those who died had smaller lung capacities when they were examined in 1990 and had more evidence of severe hydronephrosis. When surveyed in 1990, those who later died also were less independent, got out and about the community less often, and described themselves as generally less healthy than other study participants. Interestingly, however, they were less likely to have described the years just before their as the dreariest part of their lives.

Morbidity: Illnesses and Complications

Data examining morbidity -- illnesses, complications, and medical problems -- were collected from the personal interviews, during physical examinations conducted by an SCI-trained physician and via diagnostic and laboratory tests. Most important, all medical records -- from the initial admission 20 or more years ago, to the present -- were reviewed.

This yielded more than 27,000 diagnoses, operations, or procedures at the 1990 assessment that occurred at some point during the postinjury lifetime of study group member. Between 1990 and 1993, another 2,636 diagnoses or procedures were recorded.

Up until 1990, the most frequently occurring diagnoses was pressure sores, with an annual incidence of 23.1 percent. Moreover, the incidence of pressure sores increased with each 10-year increase in age after 30, but it decreased with more years postinjury. Contradictory as this appears, it seem to suggest that older individuals who had been injured shorter periods of time reported more sores than younger people injured for longer times.

Urinary tract infection with clinical symptoms was the second most frequent diagnosis, with an annual incidence of 20 percent in the years prior to 1990. Infections showed a dramatic increase in incidence among those SCI survivors who were over age 60 and a slight increase in frequency between the 10th and 30th years postinjury. There was no greater incidence of urinary infections when comparing those who had died with those still living. Between 1990 and 1993, these two leading diagnoses reversed themselves. Urinary tract infections became the most prevalent, followed by pressure sores.

While in the overall sample no other diagnosis came close to the frequency of pressure sores and urinary tract infections, there still were some patterns that emerged when study participants were grouped by injury severity, age, and duration of injury.

First, some conditions were associated with the type of neurologic injury. Persons with tetraplagia were more likely to have problems with chest infections, spasticity, perceived abdominal pain, and general malaise than those with either paraplegia or very incomplete injuries. They also had twice as many procedures to remove bladder stones or catheter-related procedures, and they accounted for the vast majority of the many already reported urinary tract infections. Those with paraplegia, on the other hand, reported more musculoskeletal problems like join pain and stiffness, as well as more pressure sores, diarrhea, and constipation. Those with very incomplete injuries -- most of whom were ambulatory -- tendered to have problems with fractures, cystitis, and motor and sensory changes.

Second, there were conditions that were associated with increasing age. These included operations of the cardiac, internal, and nervous systems; pneumonia; atelectasis; respiratory infections; kidney problems; fainting; and headaches. There were also indications that pressure sores were more closely related to age than to how long the individual had been injured.

Finally, there were those conditions associated with the duration of the disability rather than age. These included a range of musculoskeletal problems, as well as rectal abcesses and bleeding and genitourinary problems among men.

During the 1990 data collection effort, these latter two categories were analyzed together to identify the problems in an important subgroup of study participants: those who were both the oldest and the longest injured. The people in this unique group experienced gastrointestinal conditions such as digestive system operations, diarrhea or constipation, gastric disorders, and nausea and vomiting. Genitourinary conditions such as bladder or kidney stone removal, catheter procedures, pyelonephritis, or renal failure also were apparent in this subgroup. Other conditions that increased in frequency with both age and years postinjury included infectious diseases, neoplasms, motor or sensory loss, cardiovascular and respiratory conditions, and fractures and dislocations.

Finally, in the study group as a whole, while pressure sores and urinary tract infections proved to be the most frequent complications at both data collection points, there was one additional area of concern of almost equal prevalence. Though not specifically a medical diagnosis, functional decline or decreasing physical independence was an adverse outcome of long-term spinal cord injury that was documented in 22 percent of this study sample. For this particular investigation, functional decline had been defined as at least a 1-hour increase per day in the amount of assistance that was needed. Thus, the level of independence prior to the study was less important than the fact that there had been an increased need.

One-quarter of all those whose needs for help had increased blamed fatigue and weakness. Another 25 percent related this to specific medical problems. Eighteen percent identified pain an d stiffness, 14 percent attributed the increased need for help to other injuries and age. Only 5 percent blamed weight gain for their needing more help -- despite the fact that almost 40 percent of the 62 individuals said weight gains had made it harder for them to perform their activities of daily living.[8]

As a group, those needing more help were significantly more likely to have voiced complaints of shoulder pain, weight gain, and recent postural changes, such as scoliosis. Overall, though, it was age that was most strongly associated with the need for more help. Those who needed more assistance were an average of 6 years older than those who weren't requiring more help.[8]

For those with paraplegia, transfers to and from the wheelchair posed the biggest problem as help needs escalated. Participants with tetraplegia, on the other hand, tended to need extra help with mobility first, then with transfers.[8]

Indications are that physical independence decreased further between 1990 and 1993. This was detected by a change in participants' scores on CHART (the Craig Handicap Assessment and Reporting Tool), an instrument that measures community integration in five areas: mobility, occupation, social integration, economic self-sufficiency, and physical independence.[9] Scores also had declined in the area of social integration, which measures the extent to which individuals are socially involved and interacting with others around them.

General Health and Life Satisfaction

Findings that describe only increasing medical and functional complaints, however, don't tell the whole story. Despite the large number of reported complications and the presence of functional decline, many people seemingly were maintaining good health. In 1990, more than 75 percent reported feeling generally healthy. Over the following 3 years, their perceptions of their overall health actually may have improved, for when resurveyed in 1993, even more -- 89 percent -- said they felt healthy. Their age, length of time postinjury, or neurologic status did not significantly affect these percentages one way or the other. Only one subgroup reported a worsening of general health between 1990 and 1993: those who had been injured 40 or more years.

Secondly, despite all of their medical complaints and documented diagnoses, individuals were satisfied with their lives. In response to the most straightforward question asked -- "Rate your quality of life as: very poor, poor, fair, good or excellent" -- 74 percent said it was either good or excellent. Moreover, there were indications that this represented an improvement over time:

* Only 56 percent imagined they would have considered their quality of life to be good or excellent 20 years ago, before the study was done.

* The number of people considering their quality of life to be poor or very poor had dropped. Twenty-four percent said they would have rated their quality of life either poor or very poor 20 years ago, while only 4 percent rated it similarly at the time the study was done in 1990. Indeed, the only study participants who said their quality of life was getting worse were people who had been hurt more than 30 years.

In general, perceived health and quality of life were related. Overall, those who reported generally good health also tended to have scored higher on the various measures of perceived quality of life, life satisfaction, and well-being, and they generally scored lower on measures of perceived stress and depression. Nonetheless, in the group as a whole, there were some decreases over time. Life Satisfaction Index scores,[10] for example, had decreased between 1990 and 1993. Perceptions of well-being also declined slightly during the 3-year period, reflected by participants' increasing complaints of feeling bored, lonesome, and restless, as documented on the Index of Psychological Well-being.[11]

Time, however, seemed to have a positive effect on stress. When queried in 1993, it was those study participants who were oldest and who were injured longest who reported the least stress, while those with the most severe disabilities or the most neurologic involvement reported the most stress. Nonetheless, as a group, the SCI participants reported less stress -- particularly nervousness and feelings of being unable to cope -- than their nondisabled spouses, who completed the same instrument, the Perceived Stress Scale,[12] in 1993. And, as reflected by scores on the Center for Epidemiologic Studies Depression Scale,[13] depression scores were lowest in those who had been injured the longest. And, once again, when compared with their nondisabled partners, the SCI survivors in general reported less depressive symptoms.

Finally, in terms of their needs and priorities, as measured by the Quality of Life and Individual Needs Questionnaire,[14] the group reported that their relationships with their families and their need for learning had grown increasingly important to them.

Tying It All Together: Identifying Risk Factors

In an attempt to predict various outcomes of long-term spinal cord injury, all of the already described data were used to develop risk models for the study sample. Working with consumers, health professionals, and other experts in the field, several outcomes -- such as pressure sores, shoulder pain, or decreasing life satisfaction -- were identified. For each, potential predictors of these outcomes also were identified. For example: obesity and age were examined as possible predictors for pressure sores; duration of injury, economic status, and depression were considered as some of the potential predictors of decreasing life satisfaction.

Then, in each case, findings from 1990 -- diagnoses, scores on the various psychosocial instruments, responses to survey questions, and other collected data -- were examined with respect to specific medical, functional, and psychosocial outcomes or problems that appeared in 1993. Two regression techniques were used -- logistic regression for dichotomous outcomes, such as those which measured the presence or absence of a condition, and linear regression for continuous outcomes, such as those typical of the various psychosocial instruments on which a wide range of scores were possible. Each was used, as appropriate, to predict an individual's risk of a given outcome, based on factors that were present 3 years earlier. A few of the risk factors that were identified are described below:

Pressure Sores:

Several characteristics placed SCI survivors at risk for pressure sores;

* Participants with paraplegia were more likely to have pressure sores than other SCI survivors.

* Those with an existing pressure sore -- anywhere and of any -- severity were also more likely to have a new sore in 1993.

* Study participants with abnormal pulses in the feet and lower extremities in 1990 had a three times greater risk of pressure sores later.

* Those who did not work had more pressure sores in 1993 than those who were working in 1990.

Upper Extremity Pain

Arm and shoulder pain in 1993 also was somewhat predictable:

* Those who had lower scores on the tests for psychosocial well-being reported more upper extremity pain 3 years later.

* Previous complaints of upper extremity pain more than double the chances of having upper extremity pain in 1993.

* Limitations in range of motion also more than doubled the likelihood of upper extremity pain 3 years later.

Life Satisfaction

Several characteristics predicted more satisfaction with life, as measured by the Life Satisfaction Index.[11]

* Those with the highest life satisfaction in 1993 tended to be younger, had better psychological well-being, and were somewhat better off financially.

* As a group, those who reported being the most satisfied with their lives in 1993 were more involved socially in 1990, had reported less fatigue, and were less likely to be overweight.

Decreased Physical Independence

* Among paraplegics, greater age predicted declines in independence.

* Previous changes in the durable medical equipment they used were associated with less independence in 1993

* Having an indwelling catheter, or having had to change from the bladder management program they had used initially predicted declining function in paraplegics.

* Finally, paraplegics who had reported fatigue 3 years earlier were less able to function independently.

Fatigue

A range of symptoms and signs predicted:

* People with fatigue in 1993 were more likely to have reported fatigue in 1990 also, and they had lower blood pressure in 1990.

* Participants with poorer perceived health -- those who said they did not feel generally healthy in 1990 -- and who had scored more poorly on psychosocial well-being tests were more likely to report fatigue in 1993.

Conclusion

In conclusion, the goal of this Rehabilitation Research and Training Center on Aging with Spinal Cord Injury to identify problems that accompany aging with a spinal cord injury, to describe their impact and their characteristics, and to explain the characteristics of those who experience them. Findings that are useful to clinicians working with aging SCI survivors can already be found in even this preliminary research. For example, this research suggests that:

* Many of the same risks nondisabled people face are equally important -- or more important -- for SCI survivors. The incidence of cardiovascular problems, for example, is very similar, while the risk for overuse injuries among people with spinal cord injuries may be far greater. Although these data indeed indicate that such injuries are a severe problem, they do not address the breadth of the risk -- a risk that results from decades of making incredible weight-bearing demands on shoulders, elbows, and wrists.

* Certain conditions are associated more with age, others with length of injury. For example, pressure sores and respiratory problems appear to be more of an issue with increasing age. This knowledge that older individuals, even if not long-injured, are most at risk may help clinicians intervene before problems do occur. Similarly, the finding that musculoskeletal problems are associated more with longer durations of injury than with age helps clinicians anticipate and target other needed interventions.

* Issues, characteristics, and behaviors at one point in time that predict adverse outcomes at a later point in time are vital fodder for prevention. Even those that seem obvious -- such as pressure sores or upper extremity pain in 1990 predicting the same problems in 1993 -- tell us that these problems do not just go away on their own. Interventions or behavioral changes are needed if the ongoing cycle is to be broken.

* These research findings tell us that life satisfaction and quality of life are vital concepts. Neither is totally dependent upon the level or severity of the disability or on the number of medical complications, yet each seems to be very important as a predictor of future outcomes. Another seemingly vague concept -- fatigue -- appears to be an equally important predictor of future problems. Clearly, clinical complaints of fatigue -- as well as depression, or decreased life satisfaction -- should not go unaddressed. Unacknowledged and untreated, they may well lead to costly and compromising complications.

Finally, these, findings -- particularly those relating to quality of life -- tell us that aging is not the entirely negative process that many people believe it to be. These data show, despite the appearance of a host of potential problems and health complications, that it is not as bad as many people imagine. Those who are in the midst of this previously unstudied process called aging with a spinal cord injury are feeling pretty good. They are happy with their lives and are glad to be alive. of

The authors' research is conducted at the Rehabilitation Research and Training Center on Aging with Spinal Cord Injury which is made possible by funding from the National Institute on Disability and Rehabilitation Research at U.S. Department of Education (grant award # H133B30040).

References

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[5.] Go, B.K., DeVivo, M.J., and Richards, J.S. (1995). The epidemiology of spinal cord injury. In S.L. Stover, J.A. DeLisa, & G.G. Whiteneck (Eds.). Spinal Cord Injury: Clinical Outcomes of the Model Systems. Gaithersburg, MD: Aspen Publishers.

[6.] The International Classification of Diseases. 9th Edition. Clinical Modification (1978). Ann Arbor, MI: Commission of Professional and Hospital Activities.

[7.] Whiteneck, G.G., Charlifue, S.W., Frankel, H.L., Fraser, M.H., Gardner, B.P., Gerhart, K.A., Krishnan, K.R., Menter, R.R;, Nuseibeh, I., Short, D.J., & Silver, J.R. (1992) Mortality, morbidity, and psychosocial outcomes of persons spinal cord injured more than 20 years ago. Paraplegia, 30, 616-630.

[8.] Gerhart, K.A., Bergstrom, E., Charlifue, S.W., Menter, R.R., & Whiteneck, G.G. (1993). Long-term spinal cord injury: functional changes over time. Archives of Physical Medicine and Rehabilitation, 74,1030-1034.

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

[10.] Wood, V., Wylie, M.L., & Sheafor, B. (1969). An analysis of a short self-report measure of life satisfaction: correlation with rater judgments. Journal of Gerontology, 24(4),465-469.

[11.] Berkman, P.L. (1971). Measurement of mental health in a general population survey. American Journal of Epidemiology, 94(2), 105-111.

[12.] Cohen, S., Kamarack, T., & Mermelstein, R. A global measure of +perceived stress. Journal of Health and Social Behavior, 24, 385-396.

[13.] Radloff, L.S., & Teri, I. (1986). Use of the Center for Epidemiologic Studies Depression Scale with older adults. Clinical Gerontology, 5119-136.

[14.] Flanagan, J.C. (1978). A research approach to improving quality of life. American Psychologist, 2, 138-147.