Abstract
Objective: To identify differences in personal characteristics, health outcomes, and hospital utilization as a function of ambulatory status among adults with chronic SCI.
Design: Prospective cohort study linked to state administrative billing data.
Setting: Population-based SCI Registry from the Southeastern United States.
Participants: 1,051 adults (>18 years old) with chronic (>1-year), traumatic SCI.
Outcome Measures: The self-report assessment (SRA) included demographic, injury and disability characteristics, health status, psychological and behavioral factors, and participation and quality of life (QOL) variables. We linked cases to administrative billing data to assess hospital utilization, including Emergency Department (ED) visits and inpatient (IP) admissions (through the ED and direct IP) in non-federal state hospitals within the year following the SRA.
Results: There were 706 ambulatory and 345 non-ambulatory participants. We found significant differences across all sets of factors and significant differences in hospital utilization metrics. Ambulatory adults had fewer ED visits (36% vs 44%), IP admissions through the ED (11% vs 25%) and IP only admissions (9% vs 19%) and spent fewer days in the hospital for both admissions through the ED (0.9 vs 4.6 days) and IP only admissions (0.7 vs 3.1 days). They also reported having fewer past year ED visits (44% vs 62%) and IP admissions (34% vs 52%).
Conclusions: We identified differences in personal characteristics, ED visits and IP admissions between ambulatory and non-ambulatory adults with SCI, providing a better understanding of the characteristics of those with SCI. The findings suggest the need for separate analyses based on ambulatory status when assessing long-term health outcomes including hospital utilization.
Keywords: Emergency service, Hospital, Hospitalization, Spinal cord injuries, Walking
There are approximately 299,000 Americans living with a spinal cord injury (SCI), and roughly 18,000 new injuries occur each year (1). SCI is a heterogenous population, with multiple subgroups based on the cause (traumatic or non-traumatic), time since injury (acute versus chronic), level (cervical, thoracic, lumbar or sacral) and severity of injury (complete or incomplete). Further subgroup divisions may be made based on levels of functioning and disability, for example by functional motor scores, or whether an individual is ambulatory or non-ambulatory. Of the roughly 67% of individuals who have an incomplete SCI (1), many are able to maintain or regain the ability to walk, though to varying degrees. While there are noticeable differences, there has been limited research stratifying or directly comparing the characteristics of those with chronic SCI who are ambulatory to those who are not. Such research is necessary to better understand how the ability to walk relates to long-term health and well-being.
Ambulation is a primary goal of rehabilitation, and as such has been widely studied within the SCI population. A notable body of literature focused on short-term interventions to improve ambulatory function after SCI has demonstrated several clinically meaningful benefits for physiological and psychological outcomes. However, there is more limited understanding of the impact of long-term ambulation or how differences in personal characteristics between those who are ambulatory and those who are non-ambulatory may be related to health outcomes.
Based on findings from large observational studies of adults with chronic SCI, the ability to walk is associated with differences in health outcomes, hospitalizations, and ED visits (2–6). Hospital utilization has received more attention in recent years, and the evidence suggests that ambulatory status is related to utilization. In a study of adults with thoracic SCI within the first five years after injury, Miller and Anderson (3) found that ambulatory adults had lower complication rates, including urinary tract infections, pressure injuries, and hospitalizations, as well as lower associated medical costs compared to non-ambulatory adults. Krause et al. (6) found that those who were able to walk reported fewer hospitalizations compared to those who were not able to walk. In one recent study that included only ambulatory adults, having current pressure injuries, having more chronic conditions, having greater home life satisfaction, having had a prior year discharge, and walking longer distances (150 feet) more often were associated with an increased risk of hospitalization (7). Ambulatory individuals who reported greater global satisfaction and those who indicated they walked shorter distances (10 meters) more frequently had a decreased risk of hospital admission (7).
Despite the evidence that those who are ambulatory experience fewer hospitalizations and ED visits, to date, it is not clear how ambulatory individuals may differ from those who are non-ambulatory. Often, ambulation is merely considered as a variable in a regression; other times, samples are limited to those who are ambulatory or those who are not, removing the ability to draw comparisons. Therefore, a question remains: are there personal characteristics beyond the generally examined demographic and injury characteristics that may contribute to the observed differences in hospital utilization between these two groups?
Our overall hypothesis is that the two groups (ambulatory and non-ambulatory) are heterogenous and should be analyzed separately. Our purpose was to identify differences between ambulatory and non-ambulatory participants using data collected in a larger study focused on the causes of and risk factors for ED visits and related hospitalizations after SCI. The current objectives were to: (1) identify the differences in personal characteristics within a population-based cohort of individuals with chronic SCI based on ambulatory status, and (2) identify differences in hospital utilization, including ED visits, inpatient admissions, and length of stay in those who are ambulatory versus non-ambulatory.
Methods
All study procedures were approved by an institutional review board.
Participants
Study participants were recruited through the South Carolina SCI Surveillance Registry (SCSCISR) is a population-based registry of SCI occurring in the state of South Carolina (SC). All non-federal hospitals are mandated to report discharge data on hospitalizations involving SCI to the SC Office of Revenue and Fiscal Affairs, Health, and Demographics (RFAHD) through the uniform billing discharge data (UB-04). The SCSCISR does not include military or veteran hospitals and, therefore, represents the civilian population. The initial hospitalization record forms the basis for inclusion in the registry; ICD-9-CM codes are used to identify incident cases. Duplicate admissions are eliminated using personal identifiers. Individuals who have moved out of state are excluded, as well as cases presenting as late effects of SCI (i.e. not incident cases). Inclusion criteria were: (1) ≥18 years of age, (2) ≥1-year post-injury, and (3) traumatic SCI with residual effects (i.e. not complete recovery).
Data collection procedures
Self-report Assessments. Self-report data was prospectively collected by mail between 2011 and 2018. Participants were sent a preliminary letter describing the study and notifying them of the forthcoming self-report assessment (SRA), which was sent 2–4 weeks later. A second mailing was sent to non-respondents, followed by a phone call. Participants received $50 remuneration at baseline. 1,160 participants completed the SRA. Prior to matching cases to the administrative billing data, deceased cases were eliminated; therefore, the records were not counted towards hospital utilization estimates.
Administrative Billing Data. The administrative billing data source is limited to non-federal hospitals in SC. Data on hospital utilization, including ED visits, inpatient admissions (inpatient only and through the ED), and length of stay were acquired through the RFAHD, which receives medical record and charges data from SC hospitals at least quarterly. We examined records of utilization during the 12 months after participants completed the SRA. General inpatient, specialty hospital inpatient (rehabilitation, psychiatric), and long-term acute care hospitalizations were included in the calculation of hospitalizations. All types of hospital admissions (including long-term acute and specialty) were used. All 1,160 SRA respondents were matched to RFAHD administrative records, but 106 were eliminated for this analysis because the SRA responses indicated they lived out-of-state.
Self-reported measures
The SRA included multiple measures linked to the Theoretical Risk and Prevention Model (TRPM), including sociodemographic and injury factors, health status and prior utilization, psychological and behavioral factors, community participation, and quality of life (QOL) (8). Participants were asked about their age, sex, race (collapsed to white, African American or Black, or Other), highest level of education (collapsed to three categories: High School or less; Associate/Vocational; Bachelors, Masters, or PhD), annual household income from all sources (collapsed to <$10 K, $10–35 K, and >$35 K), rural or urban living status, and relationship status, dichotomized as married/couple and single. Injury characteristics included time since injury (years), injury level, categorized into cervical, thoracic, and lumbar/sacral, and ambulatory status. Ambulatory status was based on participant responses to the following question “Are you able to walk at all,” (yes, no), or responses to other ambulation questions (e.g. the distance they are able to walk, or the frequency of walking those distances) if the direct question was not answered.
Participants responded to several health status questions. They were asked about having a current pressure injury, having had urinary tract infections (UTI) or fevers in the past year, having had a prior year injury caused by a fall, having had a serious injury in the past year, and days per month that they do not get enough sleep. They were also asked about the presence of chronic conditions, assessed using standardized questions from the Behavioral Risk Factor Surveillance System (BRFSS) available at the time of the SRA development, including diabetes, heart attack, angina or coronary heart disease, stroke, high blood, high cholesterol, or cancer. The presence of chronic conditions was dichotomized to yes/no. Participants completed the Patient Health Questionnaire-9 (PHQ-9), a 9-item self-report questionnaire, used to measure depressive symptomatology (9); we classified probable major depression as PHQ-9 ≥ 15.
Measures of psychological outcomes and health behaviors included the Brief Resilience Scale (BRS), which assesses the perceived ability to bounce back or recover from stress (10), perceived emotional and instrumental support from the Berlin Social Support Scale (BSSS) (11), and items assessing prescription medication use for pain, spasticity, sleep or stress, risky alcohol use, defined as having 5 or more alcoholic drinks per day, and current cigarette smoking. Measures of participation and QOL included employment after SCI, the need for physical assistance, pain interference, several items from the Craig Handicap Assessment and Reporting Technique (CHART) mobility (hours per day out of bed, days per week out of the house) and occupation (hours in schooling, active homemaking and maintenance, volunteer work, and recreational pursuits) domains (12), and overall QOL (1 being the worst possible QOL and 10 being the best possible).
Self-reported hospital utilization measures included the number of past year ED visits and hospitalizations, dichotomized to yes or no utilization.
Analyses
All analyses were completed with SAS Version 9.4 (SAS Institute). Descriptive statistics (mean, standard deviation (SD)) or frequency (%) are presented. Frequency data were calculated using Proc Freq; Chi-Square Tests for Homogeneity were used to assess statistical significance. Means, standard deviations, and t-tests to assess statistical significance were calculated using Proc TTEST. The outcomes were not normally distributed. T-tests are relatively robust for violations of normality, but we ran Wilcoxon 2-Sample tests to confirm, and the results did not change.
Results
We linked 1,051 participants with self-report data to the administrative billing data; we were unable to determine ambulation status for 3 participants. There were 706 people who identified as ambulatory and 345 identified as non-ambulatory. The analysis of participant characteristics from the SRA identified significant differences between ambulatory and non-ambulatory adults in almost all domains – demographic and injury, health status, psychological and behavioral, and participation and QOL.
Demographic and Injury characteristics. We found that those who are ambulatory were more likely to be white, married, living in urban locations, and uninsured (Table 1). A greater percentage of ambulatory adults earned more than $35k per year. There were significant differences in the percentage of ambulatory adults with cervical (71%), thoracic (15%) and lumbar/sacral (14%) level injuries compared to non-ambulatory (50%, 44%, and 6%, respectively); the majority of those who were ambulatory had a cervical level injury, consistent with neurologically incomplete injury.
Table 1.
Differences in key demographic and injury characteristics by ambulatory status.
| % or Mean (SD) | ||||
|---|---|---|---|---|
| Ambulatory N = 706 |
Non-Ambulatory N = 345 |
Test Statistic | P value | |
| Age | 53.4 (16.4) | 44.8 (16.6) | t = −7.89 | <.0001 |
| Sex (male) | 70% | 70% | χ2 = 0.0003 | 0.99 |
| Race/Ethnicity | χ2 = 6.75 | 0.03 | ||
| White (n = 621) | 61% | 54% | ||
| AA/Black (n = 386) | 35% | 40% | ||
| Other (n = 44) | 3% | 6% | ||
| Relationship Status (Married/partnered) | 50% | 38% | χ2 = 12.12 | 0.0005 |
| Geographic location (Urban) | 70% | 64% | χ2 = 3.90 | 0.05 |
| Income | χ2 = 8.13 | 0.02 | ||
| <=$10 K (n = 312) | 29% | 35% | ||
| $10–35 K (n = 397) | 39% | 42% | ||
| >$35 K (n = 291) | 32% | 23% | ||
| Education | χ2 = 4.55 | 0.10 | ||
| High school or less education (n = 604) | 56% | 63% | ||
| Associate/Vocational (n = 271) | 28% | 24% | ||
| Bachelors/Masters/PhD (n = 158) | 16% | 13% | ||
| No health insurance | 10% | 2% | χ2 = 22.67 | <.0001 |
| Years post injury | 4.5 (5.5) | 7.0 (7.5) | t = 5.50 | <.0001 |
| Injury level | χ2 = 99.65 | <.0001 | ||
| Cervical (n = 601) | 71% | 50% | ||
| Thoracic (n = 239) | 15% | 44% | ||
| Lumbar/Sacral (n = 110) | 14% | 6% | ||
Health Status. Examining health status variables (Table 2), a greater percentage of ambulatory adults reported having major depression, chronic conditions, and more days per month with inadequate sleep. Fewer ambulatory adults reported having a pressure injury now, having a UTI in the past year and having fevers in the past year. There were not significant differences in the rates of past year serious injuries (83% and 81%) or injuries caused by a fall (17% and 13%) between ambulatory and non-ambulatory adults.
Table 2.
Differences in health status characteristics by ambulatory status.
| % or Mean (SD) | ||||
|---|---|---|---|---|
| Ambulatory N = 706 |
Non-Ambulatory N = 345 |
Test Statistic | P value | |
| Major depression (PHQ-9) | 23% | 17% | χ2 = 4.83 | 0.03 |
| Pressure injury now | 7% | 35% | χ2 = 134.39 | <.0001 |
| Chronic conditions | 65% | 49% | χ2 = 23.31 | <.0001 |
| UTIs in past year | 23% | 76% | χ2 = 257.90 | <.0001 |
| Fevers in prior year | 36% | 58% | χ2 = 43.22 | <.0001 |
| Prior year injury caused by fall | 17% | 13% | χ2 = 2.94 | 0.09 |
| Serious injuries in prior year | 83% | 81% | χ2 = 0.46 | 0.50 |
| Days/month not enough sleep | 14.5 (10.4) | 12.1 (9.9) | t = −3.52 | 0.0005 |
Psychological and Behavioral. There were significant differences on multiple psychological and behavioral factors (Table 3). Ambulatory adults scored lower on the BRS and BSSS. Fewer ambulatory adults reported they take prescription medications for pain, spasticity, sleep or stress, but they reported more days per month that pain interfered with usual activities, a participation measure. A larger percentage of ambulatory adults reported drinking more and smoking.
Table 3.
Differences in psychological and behavioral variables by ambulatory status.
| % or Mean (SD) | ||||
|---|---|---|---|---|
| Ambulatory N = 706 |
Non-Ambulatory N = 345 |
Test Statistic | P value | |
| BRS | 3.3 (0.8) | 3.5 (0.8) | t = 2.30 | 0.02 |
| BSSS perceived emotional support | 3.2 (0.6) | 3.3 (0.6) | t = 2.69 | 0.007 |
| BSSS perceived instrumental support | 3.2 (0.7) | 3.3 (0.6) | t = 3.14 | 0.002 |
| Always take medications as prescribed | 21% | 26% | χ2 = 2.78 | 0.10 |
| Never take prescription medications for pain, spasticity, sleep, or stress. | 17% | 10% | χ2 = 9.50 | 0.002 |
| Never have 5 + alcoholic drinks/day in past month | 71% | 83% | χ2 = 17.80 | <.0001 |
| Don’t smoke any cigarettes/day now | 62% | 76% | χ2 = 18.98 | <.0001 |
Participation and QOL. A greater percentage of ambulatory adults reported being employed after injury (Table 4). Fewer ambulatory adults reported needing physical assistance. On items from the mobility dimension of the CHART, assessing the individual’s ability to move about effectively in their surroundings, ambulatory adults reported more hours per day out of bed and more days per week out of the house. In the occupation dimension, ambulatory adults reported fewer hours per week in school more hours per week in active homemaking; there were not significant differences in the time spent in volunteer activities or recreational activities. There were not significant differences in reported QOL between ambulatory and non-ambulatory adults.
Table 4.
Differences in participation and QOL variables by ambulatory status.
| Ambulatory N = 706 |
Non-Ambulatory N = 345 |
Test Statistic | P value | |
|---|---|---|---|---|
| % or Mean (SD) | ||||
| Employed after SCI | 33% | 19% | χ2 = 20.46 | <.0001 |
| Days/month pain interfered with usual activities | 15.6 (12.0) | 12.5 (11.7) | t = −3.92 | <.0001 |
| Need physical assistance | 27% | 72% | χ2 = 187.32 | <.0001 |
| Days/week leave house | 4.4 (4.2) | 3.5 (3.2) | t = −5.80 | <.0001 |
| Hours/day out of bed | 12.4 (12.1) | 10.4 (9.9) | t = −6.38 | <.0001 |
| Hours/week in school | 0.8 (0.5) | 1.5 (0.9) | t = 2.13 | 0.03 |
| Hours/week homemaking | 9.6 (11.3) | 6.3 (9.4) | t = −4.85 | <.0001 |
| Hours/week volunteer work | 0.7 (2.3) | 0.7 (2.8) | t = 0.19 | 0.85 |
| Hours/week active recreation | 4.3 (5.8) | 4.4 (5.9) | t = 0.30 | 0.76 |
| Overall QOL (1 worst-10 best) | 6.6 (6.4) | 6.4 (6.2) | t = −0.88 | 0.38 |
Hospital Utilization. The analysis of hospital utilization data found significant differences between ambulatory and non-ambulatory participants with SCI (Table 5). Fewer ambulatory adults visited an ED in the year following the SRA (36% vs 44%), and they experienced fewer IP admissions, both through the ED (11% vs 25%) and direct IP admits (9% vs 18%). They also had significantly fewer days spent in the hospital. Based on the self-report data, ambulatory adults had fewer past year ED only visits (44% vs 62%) and IP admissions (34% vs 52%).
Table 5.
Hospital utilization based on ambulatory status.
| % or Mean (SD) | ||||
|---|---|---|---|---|
| Ambulatory N = 706 |
Non-Ambulatory N = 345 |
Test Statistic | P value | |
| Administrative Billing Data (during 12 months after the SRA) | ||||
| ED only visit | 36% | 44% | χ2 = 6.16 | 0.01 |
| IP admission through ED | 11% | 25% | χ2 = 37.86 | <.0001 |
| IP only admission | 9% | 18% | χ2 = 19.18 | <.0001 |
| Days for IP admits through ED | 0.9 (4.0) | 4.6 (14.9) | t = 4.62 | <.0001 |
| Days for IP only admission | 0.7 (4.2) | 3.1 (12.1) | t = 3.59 | 0.0004 |
| SRA Utilization Data (prior 12 months) | ||||
| ED only visit | 44% | 62% | χ2 = 30.08 | <.0001 |
| IP admissions | 34% | 52% | χ2 = 28.51 | <.0001 |
Discussion
This study contributes to the body of literature and adds to our understanding of the heterogeneity in SCI by exploring the personal characteristics of those with SCI who are ambulatory compared to non-ambulatory, and examining differences in future hospital utilization, including ED visits and IP admissions, based on ambulatory status. Due to the observed differences between those who are ambulatory and those who are not, it is more apparent that findings for one group are not necessarily generalizable to the other, and to the extent possible these groups should be analyzed separately in future research.
Heterogeneity among those with SCI has been documented and several factors that may influence outcomes have been identified, including injury related characteristics (e.g. cause, level and severity, age at injury, motor score, and time since injury), personal characteristics, and socio-environmental factors (13, 14). Surprisingly, ambulatory status has not been adequately studied, though evidence from research, clinical practice, and observation suggest that ambulatory adults with SCI and those with non-ambulatory SCI comprise distinct populations. To date, there has been limited research describing the personal characteristics of ambulatory and non-ambulatory adults from a more encompassing perspective, beyond demographic or clinical characteristics, and few studies have directly compared long-term outcomes among those who can walk and those who cannot (3, 6). We found significant differences across multiple domains – health, psychological and behavioral, and participation – that may ultimately impact long-term health and rehabilitation outcomes.
Consistent with previous findings, fewer ambulatory adults reported having current pressure injuries or past year urinary tract infections and fevers (3, 15). Ambulatory adults reported needing less physical assistance and spending more hours out of bed and more days per week out of the house, two positive measures of mobility indicating less handicap (i.e. loss of participation) (12). A larger percentage of ambulatory adults were employed, which is consistent with other findings (16).
Not all findings favored those with ambulatory SCI. Compared to non-ambulatory adults, a greater percentage of ambulatory adults reported having chronic conditions, and greater number of nights of inadequate sleep. Consistent with previous findings, depression was more prevalent among those who were ambulatory (6, 17). Ambulatory adults also reported lower resilience and perceived support. Although fewer ambulatory adults reported taking medications for pain, spasticity, sleep, or stress, they reported significantly more days that pain interfered with usual activities and were more likely to exhibit high risk behaviors including binge drinking (five or more alcoholic drinks per occasion) and smoking. These health conditions and behavioral factors have the potential to negatively impact activities of daily living, participation, and QOL, as well as future health outcomes, hospital utilization, and even mortality. Overall, the findings highlight unmet needs within the ambulatory population and identify potential targets for interventions that can be addressed to optimize health and well-being.
There were no significant differences between ambulatory and non-ambulatory adults in terms of past year fall related injuries or serious injuries. We found a large percentage, over 80% of both ambulatory and non-ambulatory adults reported serious injuries in the past year. In the year prior to the SRA, 17% of ambulatory and 13% of non-ambulatory adults experienced a fall related injury. While our present study does not include data on fall incidence, only falls resulting in injury, in a 2019 review, Kahn et al. found that 78% of ambulatory individuals and 69% of wheelchair users fell at least once over a year period (18). The high rates of injury are notable, as unintentional injuries, including falls, are a public health concern associated with adverse outcomes including hospital utilization and mortality. The findings that both groups experience similar rates of serious and fall related injuries should alert healthcare providers, caregivers, and stakeholders of potential unmet needs. Because the use of assistive devices and independence in mobility have been associated with fall risk (18–20), these factors should be considered in the development of strategies to address these needs.
Lastly, we did not find significant differences in overall QOL between ambulatory and non-ambulatory adults in our population-based cohort. This is not surprising, considering that QOL is a subjective measure, affected by a number of factors. It is important to note that the ambulatory and non-ambulatory populations are heterogeneous. There are factors within each group that may influence QOL, such as mode of mobility, independence in mobility, and changes over time (6, 21). In future study of these groups, it would be beneficial for researchers to consider the use of assistive devices, independence in mobility, and changes in mobility, as those factors influence several health outcomes and QOL (6, 17, 20–22).
The focus on hospital utilization among adults with SCI has increased in recent years. Previous studies have found anywhere between 37% and 57% (23–28), of individuals with SCI experience an ED visit in a given year, and among those who report past year ED use, a large percentage are subsequently admitted to the hospital (24, 28). Regression analyses have identified walking ability and independence as factors associated with hospitalizations and ED visits, and ambulatory adults have been observed to experience fewer hospitalizations (2–4). We found significant differences across several metrics of utilization – both from administrative and self-report data. Notably, ambulatory adults experience less utilization; a lower percentage of adults with ambulatory SCI experience ED only visits (36%), IP admissions through the ED (11%), IP only admissions (9%), and fewer days spent in the hospital for each admission. They also self-report fewer ED visits and hospitalizations. The observed differences in hospital utilization support future studies focusing specifically on ambulatory or non-ambulatory populations to better identify predictors of utilization.
Clinical implications
These findings may be used to provide education and raise awareness about the differences between ambulatory and non-ambulatory adults with SCI. By having a more complete description of the characteristics of those with chronic SCI based on ambulatory status, and the association of ambulatory status with hospital utilization, rehabilitation professionals may better understand how ambulation relates to health and well-being of those with SCI, and research and interventions may be tailored for these groups. In essence, there appears to be qualitative differences in their profiles which cannot simply be interpreted in terms of severity of SCI alone. For example, those who are non-ambulatory may experience greater resilience and social support and reduced depression compared to those who are ambulatory. Those who are ambulatory certainly have less severe mobility impairments, yet a greater risk of several types of complications (e.g. greater reports of depression, more chronic conditions, greater number of days pain interfered with usual activities).
Methodologic considerations
There are several important methodologic considerations to note when interpreting these findings. First, we used a combination of self-report and administrative billing data. This has the strength of not relying on a single data source, and allowed us to utilize self-report data for those variables which were not defined in the billing data. However, self-report data is always susceptible to reporting errors and recall bias. Second, we identified the relationship of self-report data with future ED visits. This is a particular strength when compared with a single cross-sectional measurement. Third, we used a cohort identified from population data which captured all civilian cases of SCI within the state. This is a strength compared with studies that utilize specialty hospital populations where some people fall through the cracks of the healthcare system. Nevertheless, there still may be response biases in participation among those within the population-based system. Lastly, the findings are representative of a select geographic region. This should not be a major issue however, since our focus was comparison of ambulatory and non-ambulatory SCI.
Future research
Observational cohort studies play a key role in SCI research, informing future clinical studies and decision making. Better understanding of the characteristics and outcomes within the ambulatory and non-ambulatory populations may allow clinicians and researchers, as well as caregivers and those with SCI to improve care, management, rehabilitation, and prevention efforts. These findings provide rationale for focusing future studies specifically on those who are ambulatory or non-ambulatory, stratifying cohorts or clearly differentiating ambulatory and non-ambulatory SCI in subgroup analyses. It is important to break out these unique subpopulations to better conceptualize and identify their individual needs, as drawing average statistics across ambulatory and non-ambulatory SCI may produce results that are not representative of either group.
Additional research is needed to investigate factors within each group related to important outcomes, including identifying the aspects of ambulation (e.g. assistive device use, independence in ambulation, motor scores, etc.) that are most strongly related to favorable or adverse outcomes. Also, research is needed to better understand transitions from ambulatory to non-ambulatory SCI as individuals age and how changes in ambulatory status over time may affect outcomes. Those who are non-ambulatory may face changes with loss of mobility over time and transition to more restrictive modes of mobility (e.g. from manual to electric wheelchair).
Conclusions
Despite the commonality of having an SCI, our findings illustrate significant differences among those who are ambulatory compared to those who are non-ambulatory, and suggest the need for separate analyses based on ambulatory status when assessing long-term health outcomes including hospital utilization. The differences in characteristics that we found across demographic, health status, psychological and behavioral, participation and QOL factors as well as hospital utilization outcomes are important to consider in the design, conduct, and analysis of future studies.
Suppliers
SAS for Windows [computer program]. Version 9.4. Cary, NC: SAS Institute; 2015.
Abbreviations
- ED
Emergency Department
- SCI
Spinal cord injury
- SCISRS
SCI Surveillance and Registry System
- RFAHD
Office of Revenue and Fiscal Affairs, Health, and Demographics
- UB-4
Uniform billing discharge data
- US
United States
Data availability statement
The datasets generated and/or analyzed during the current study are not publicly available due to the privacy concerns of study participants and are not standardized to be in a publicly interpretable format.
Disclaimer statements
Contributors None.
Funding The contents of this publication were developed under grants from the National Institute for Disability, Independent Living, and Rehabilitation Research, NIDILRR [90IFRE0028]. However, the contents of this publication do not necessarily represent the policy of NIDILRR, and do not imply endorsement by the funding agency or federal or state governments.
Conflicts of interest Authors have no conflict of interests to declare.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The datasets generated and/or analyzed during the current study are not publicly available due to the privacy concerns of study participants and are not standardized to be in a publicly interpretable format.