This study aimed to explore the disability changes in patients with SCI and was conducted by enrolling patients from the spinal surgery wards of three Class III hospitals in Hefei, Anhui Province, China. Two variant trajectories were identified with significant.
Two variant trajectories were identified with significant disability differences at 6 months after SCI, with 93.3% and 6.7% of the participants belonging to the high, and low trajectories, respectively. These findings indicates that disability is the main factor in the early rehabilitation of most individuals after SCI. Some factors closely related to disease (e.g, ASIA grade), and psychosocial factors such as depression, are associated with the level and change rate of the disability track.
Previous studies have compared changes in disability over time, involving only one area of disability, such as self-care ability,27 cognition,28 or social participation.29 This study incorporated some fields into a composite concept of disability that really reflects the ability of patients to take care of themselves, get along with others, entertain and participate socially.3,4 It was found that compared to the higher trajectories, which included more than 90% of the participants, individuals assigned to lower trajectories have occupational differences. Research by Schwegler 30 showed that it is difficult for patients with SCI to continue their original work, especially physical activity. In contrast, in a Swiss cohort it was found that cognitive-oriented work can assist with returning to work.
The disability trajectories found in our study were similar to those in other populations and revealed some interesting features. The relationship between occupation and disability remains inconclusive. In this present study, ASIA classification grade, annual family income, hope, depression, social support, and PTSD were included in the regression model, and the relationship between the two was no longer significant. This may be because,in this present study, only the occupations of patients before injury were collected, while an Australian study showed that individuals returning to work after SCI not only need to have knowledge, skills, and interests that match their jobs, but also need the government to provide corresponding support, such as skill training.31 However, the patient cohort in this present study was from Anhui, China. The participants were mainly farmers and workers engaged in heavy manual labor (80.5%). On the one hand, it is difficult to fully recover limb function to the level before the injury in a short time (6 months). Also, there is no professional skill training and relevant policy support for SCI at present in China. In terms of annual income, low-income patients are more likely to be assigned to the track of continuous high disability, and this is consistent with a result of the cohort study on income level from the United States and the United Kingdom.32 The disability rate of low-income individuals (48%) is significantly higher than high-income individuals (17%), and this may be because income level affects the disease affordability of individuals.
Consistent with this study, a positive correlation was found in the higher ASIA with SCI and disability which has been previously reported.33 A cross-sectional study from Vietnam, shows that the Activities of Daily Living (ADL) scored higher with a ASIA-D compared to someone of ASIA-B.34 This may be because a more severe injury can cause a higher disability level. Therefore, a better understanding of the degree of injury plays an important role in reducing the degree of disability in patients. ASIA grade functional independence, motor function, and getting along with others have been described in previous studies with SCI. Higher grade ASIA patients with SCI may experience more spasms,35 and secondary health conditions such as neurogenic rectum, neurogenic bladder. Also, neuropathic pain influences their physical independence, activity limitation and participation limitation compared to the patients with incomplete SCI.36 Therefore, there is a need to provide continuous and better rehabilitation services for incomplete SCI, including mobile assistive devices such as exoskeleton robots, and continuous home care services to reduce the speed of developing disability.
Positive psychosocial determinants such as hope and social support are relevant to disability of individuals. In a study in pain trajectories after SCI, Braunwalder found that individuals with more optimism, higher levels of social support, and less anxiety were more likely to report pain relief 1 month after the onset of SCI.37 However, given that psychosocial resources and early disability trajectories after SCI have not been researched before, previous research on SCI is limited. Previous studies on disability showed that high levels of hope,38 and social support39 can reduce disability, and this can be explained by the fact that individuals with high hope levels and social support tend to adopt a positive attitude to adapt to changes in their physical condition and participate in social activities to alleviate levels of disability.40 In this present study, positive psychosocial factors seem to have no connection with better disability trajectories in the final logistic regression model. The differences between this present study and previous studies could be attributed to social and cultural differences: clinical workers, patients, and family members tend to pay more attention to the treatment effect on physical function, while ignoring the impact of positive psychological factors on disability during the period of stable condition after SCI to 6 months after discharge in China.
Depression and PTSD, being negative psychosocial determinants, are persistently strong risk factors linked to disability after SCI. Data from this present study also reveal that a significant association between high depression and worse disability trajectories is supported by a meta-analysis of longitudinal studies looking at disability and post-stroke depression.41 Bonanno revealed that the depression trajectory after SCI was chronically elevated and fluctuated greatly within 1 year after SCI, and this further verifies the results of this present study in connection with between depression and the disability trajectory.42 As for PTSD, the association with disability trajectories lost significance in the final logistic regression model, most likely because of the high correlation between PTSD and the ability to make new social connections.
Clinical implications
This study showed that disability trajectories have different developmental trends over time. ASIA grade and depression level have a strong predictive function for disability 6 months after discharge. In the early screening of patients with SCI, psychosocial (depression) and disease factors (ASIA grade) might provide significant information about these patients experiencing trouble in daily life in the long term. It may give the entire rehabilitation team a target for intervention by identifying individuals with long to high disability trajectories. This early intervention may positively affect adjustment outcomes, such as depression severity.
Limitations of study
First, although a large number of participants were included in the LCGM, some data were still lost during follow-up. Although FIML was used to process missing data, there is still a possibility of bias. Second, participants were primarily farmers and workers (80.4%). They may be poorer than the general population, so findings of this present study may apply only to developing countries with relatively poor economies. As the participants change, the link between disability trajectories and their underlying factors may also change. Third, this study only explored disability trajectories from the stable stage after SCI surgery to six months after discharge. However, the length of follow-up may have affected the results. There are some measures to control for the loss to follow-up bias: First, select a relatively stable population to facilitate follow-up; Second, this study will continue to investigate the outcomes of individuals who were lost to follow-up in the future and compare them with those who completed follow-up to speculate on the impact of loss to follow-up. A multicenter, large-sample, long-term follow-up study should be conducted in the future to verify the results of this study.