Introduction

The unexpected occurrence of a spinal cord injury (SCI) may dramatically change the lives of injured people. Adaptation to the SCI requires coping with a wide range of health-related problems. These problems may, apart from the paralysis, concern various body functions, such as bladder, bowel and sexual function, autonomic function and pain. Functional problems can lead to limitations in activities and participation restrictions typically related to mobility, self-care activities, difficulties in regaining work, maintaining social relationships, participating in leisure activities and being active members of the community.1, 2 The participation restrictions are highly dependent on environmental factors, such as mobility equipment and transportation.3

The prevalence of many problems associated with SCI may vary within the phase of treatment and rehabilitation and the time after injury. It is reported that many newly injured people who met the diagnostic criteria for depression remit within 3 months of onset4 as is also the case with the orthostatic hypotension that is particularly evident in the early phase.5 On the other hand, odds ratios for pressure ulcers, autonomic dysreflexia, heterotopic ossification and need for help with activities of daily living increase over time after SCI.6

Numerous health status measures are used to assess the functional limitations associated with SCI. However, most of these measures cover only selected aspects of the whole SCI health experience and vary considerably regarding their content and psychometric characteristics.7 This degree of variation presents a number of disadvantages to workers who wish to compare or transfer data across successive phases of the continuum of care (emergency, medical, rehabilitative, outpatient and community clinical care). In addition, for comparability of outcome data across conditions and interventions, a common framework is needed.

With the approval of the International Classification of Functioning, Disability and Health (ICF)8 by the World Health Assembly, there is now a comprehensive and universally accepted framework to classify and describe the whole health experience, including environmental factors. The ICF is based on the integrative model of functioning and comprises four components: Body Functions, Body Structures, Activities and Participation, and Environmental Factors. Within these components, all items in the classification are arranged hierarchically. Categories are divided into chapters, which constitute the first level of precision. Categories on higher levels (for example, second, third or fourth level) are more detailed.

The objective of this cross-sectional study was to identify and describe the prevalence of problems in functioning experienced by individuals with SCI in the early post-acute and long-term context using the ICF.

Materials and methods

Study design

This cross-sectional, multicenter study was carried out within the international project ‘Development of ICF Core Sets for Spinal Cord Injury’ and was one of the four preparatory studies conducted in order to gather information about the relevance of functional problems in people with SCI.9 A large proportion of the data (71.4%) reported in this paper was used as an empirical basis for SCI experts to decide on the ‘ICF Core Sets for Spinal Cord Injury’.10, 11 Sixteen study centers in 14 countries participated in this study.

Individuals were included if they had sustained an SCI with an acute onset, if they were either in the early post-acute or in the long-term context, if they were at least 18 years old, if the purpose and reason of the study was understood and if an informed consent was signed. Individuals with significant traumatic brain injury or diagnosed mental disorders before SCI were excluded. Acute onset was defined as injury or disease with the development of SCI within 14 days. The early post-acute context begins with active rehabilitation and ends with the completion of the first comprehensive rehabilitation after the acute SCI. The long-term context follows the early post-acute context. This working definition is based on a worldwide consensus of researchers involved in the data collection and was approved by the steering committee of the project.

The study was approved by the ethics committees in charge of the respective study centers involved and was carried out in accordance with the Declaration of Helsinki.

Measures and data collection

The participants’ functional problems were recorded using a Case Record Form consisting of all 264 ICF categories on the second level of the classification. The presence of the problem was denoted for each category of the components Body Functions, Body Structures, and Activities and Participation using the qualifiers 0 for ‘no impairment/limitation’ and 1 for ‘impairment/limitation’. The categories of the component Environmental Factors were graded with 0 for ‘no facilitator and no barrier’, +1 for ‘facilitator but no barrier’, −1 for ‘barrier but no facilitator, and ±1 for ‘barrier and facilitator’. In addition, the qualifier ‘8’ was used if the available information was not sufficient and ‘9’ if the category was not applicable. Problems owing to a comorbidity not associated with the SCI were coded as described above and assigned as comorbidity (c).

The information regarding the ICF categories was collected by registered health professionals working in the clinical environment. The majority of information was obtained from individual interviews with persons with SCI—frequently performed with computer assistance. Clinical and demographic characteristics were retrieved from medical records. In addition, the individuals were asked to provide global ratings of their general health and well-being. The health professionals entered collected data in an electronic database.

Quality assurance

The health professionals were trained in a 2-day workshop in the principles and application of the ICF, in performing individual interviews and electronic data entry. Accuracy of data collection was assured by automatic error checks included in the database that helped to identify missing or implausible data without undue delay. The international project coordinator provided monitoring of the collected data.

Data analysis

Sample characteristics were analyzed using descriptive statistics. For the ICF categories assigned to the components Body Functions, Body Structures, and Activities and Participation, absolute frequencies and relative frequencies (prevalence) of impairment/limitation in the study sample are reported along with their 95% confidence intervals. For ICF categories representing Environmental Factors, absolute frequencies and relative frequencies (prevalence) of people who regarded a specific category as either barrier or facilitator or both are reported. The sample size for the calculation of the prevalence differs for each ICF category, as only participants with SCI for whom health professionals could judge whether a problem is present or not were considered. To clarify, missing values, as well as the response options ‘not applicable’ ‘not definable’ and ‘comorbidity’ are not taken into account.

Results

The data were collected from June 2006 to January 2008 by the trained health professionals in the respective study centers. Most of the interviews were performed by physicians or physical therapists. In total, 1052 people with SCI participated in the study. Four individuals were excluded from the analysis because they did not fulfill the inclusion criteria.

The majority of data (30.2%) came from countries of the South-East Asian world region (Thailand, India, Vietnam and Malaysia). The European region (Denmark, Germany and Switzerland), Western Pacific region (New Zealand and Australia), Eastern Mediterranean region (Israel) and region of the Americas (USA, Canada and Brazil) were evenly represented with 14.1–19.2% of the data, whereas the African region (South Africa) contributed to 6.4% of the data (see Table 1).

Table 1 Number of observations stratified by country
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Table 2 shows the sample characteristics. People with SCI in the early post-acute context significantly differed from the people in the long-term context regarding age, SCI severity, setting, time since SCI onset, American Spinal Injury Association (ASIA) Impairment Scale (AIS) grading, non-traumatic etiology and self-rating of general health and functioning. Tables 3, 4 and 5 show the ICF categories in which problems were documented in >20% of the persons with SCI in the early post-acute or in the long-term context. Table 6 shows the ICF categories of the component Environmental Factors considered to be a barrier, a facilitator or both in >20% of the persons with SCI in the early post-acute or in the long-term context.

Table 2 Sample characteristics
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Table 3 Prevalence (95% CI) of impairment in the ICF categories of the component ‘body functions’
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Table 4 Prevalence (95% CI) of impairment in the ICF categories of the component ‘body structures’
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Table 5 Prevalence (95% confidence interval (CI)) of impairment in the ICF categories of the component ‘activities and participation’
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Table 6 Prevalence (95% CI) of a barrier, facilitator or both in the ICF categories of the component ‘environmental factors’
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For the component Body Functions, 35 of the 79 ICF categories were reported with a frequency over 20% in both the early post-acute and the long-term context. The ICF categories b126 Temperament and personality functions and b130 Energy and drive functions had a frequency over 20% only in the early post-acute context. The ICF category b126 Temperament and personality functions was significantly more frequent in the early post-acute context, whereas problems in 11 ICF categories such as b820 Repair functions of the skin were significantly more common in the long-term context. The most common categories for both situations were b730 Muscle power functions, b735 Muscle tone functions, b740 Muscle endurance functions and b770 Gait pattern functions showing a prevalence exceeding 93%.

For the component Body Structures, 12 of the 40 ICF categories reflected the common problems experienced by individuals in both contexts. The highest prevalence was reached by the categories s120 Spinal cord and related structures, s760 Structure of trunk and s810 Structure of areas of skin in both contexts. Three categories were significantly more common in the long-term context.

For the component Activities and Participation, 47 of the 81 ICF categories reflected the common problems experienced by individuals in both contexts. The most common categories for both situations were d435 Moving objects with lower extremities, d450 Walking, d455 Moving around and d460 Moving around in different locations. Four of the 81 ICF categories had a frequency over 20% only in the early post-acute context and one only in the long-term context. Thirty-four categories were significantly more common in the early post-acute context, whereas only d940 Human rights was reported significantly more frequently in the long-term context.

For the component Environmental Factors, all of the 64 ICF categories were commonly reported as either a barrier, a facilitator or both in the early post-acute and the long-term contexts. The highest prevalence of >90% were reached by the categories e310 Immediate family, e355 Health professionals and e580 Health services, systems and policies in both contexts and e450 Individual attitudes of health professionals in the early post-acute context. Eleven categories were significantly more common in the early post-acute context, whereas the ICF categories e210 Physical geography and e225 Climate were reported significantly more frequently in the long-term context.

Discussion

The spectrum and prevalence of problems experienced by individuals with SCI worldwide were examined in this study. The ICF was used as reference as it provides a comprehensive framework and common language. The most common problems identified highlight the diversity of problems associated with a SCI and the relevance of environmental factors. Furthermore, the results indicate potential differences between the prevalence of problems in the early post-acute versus the long-term context.

The high prevalence of typical impairments in Body functions, such as pain, defecation, urination and movement-related functions, supports previous findings in the SCI literature.12 When interpreting the high prevalence of pain (87%) in our sample, it must be taken into account that any problem regarding pain is included in this second-level ICF category b280 Sensation of pain irrespective of the intensity, duration, location or nature of the pain. To provide a more detailed description of pain problems when applying the ICF, the specific third- and fourth-level ICF categories would be more appropriate. The SCI experts involved in the decision-making and consensus process, which led to the first version of the Comprehensive ICF Core Sets for SCI, also identified this need and included a number of third- and fourth-level ICF categories in the ICF Core Set allowing a detailed description of the participants’ pain problems.10, 11

Some impaired body functions, such as sensations associated with the digestive system, thermoregulatory functions, sexual functions and skin-related functions, were found to be more prevalent in the long-term context. The more frequently impaired thermoregulatory functions in people in the long-term context may be due to the higher proportion of in-patients among the early post-acute sample who may experience a more constant environmental temperature and thus are not challenged by managing variations in temperature.13 The higher prevalence of problems regarding skin functions in the long-term context is supported by several studies reporting an increasing prevalence of pressure sores with time after injury.14 Information on sexual functions was not available for >20% of the participants in the early post-acute context in our study. Again it should be taken into account that most of these individuals were in-patients and it could be expected that they become more aware of these problems when they are back home with their families and partners. Therefore, it might not be surprising that the prevalence was higher for the long-term context. The finding that sensations associated with the digestive system were more frequent in the long-term group is supported by studies reporting an increase of bowel problems and a change of the pattern of colorectal dysfunction with time since SCI.15 The fact that several movement-related functions were more prevalent in the long-term context may be related to the higher number of people with AIS A and a fewer with AIS D. The only body functions that were found to be impaired more frequently in people with SCI in the early post-acute context were temperament and personality functions. This finding is supported by studies that reported an association between time since injury and a decreasing risk of psychopathology and depression.16

This study found a considerable prevalence for a number of Body Structures—beside the spinal cord itself—which are typically impaired in SCI, for example, structures of the trunk, pelvis, urinary system and skin. It is important to mention that the structure of areas of skin was the second most common reported structural problem with a prevalence around 50%. This finding is in line with the studies which found pressure ulcers to be the most frequent secondary medical complication with an increasing prevalence after injury and which observed a trend toward an increasing prevalence in the recent years.17, 18

Regarding the ICF component Activities and Participation high prevalence was found specifically regarding mobility and self-care. As expected, all restrictions regarding this domain were more common in people with SCI in the early post-acute context. However, about 70% of the people in the long-term context still experience limitations regarding mobility, such as maintaining or changing a body position, or transferring oneself, and about 60% have limitations in self-care activities. Several studies have also reported that the need for help in activities of daily living, specifically bathing, dressing and transfers, increases over the years.19

All of the second-level ICF categories from the component Environmental factors were found to be relevant for >20% of the sample either as a facilitator or a barrier or both. These results highlight the need to consider environmental factors when assessing functional problems and disability in people with SCI, especially when planning the transition from the facility to the community.20 Our results also indicate that support from others is a crucial factor for people with SCI. The finding that support and attitudes of others were more frequently regarded as relevant aspects in the early post-acute context may be related to an initial high need for support and an unstable self-perception that may be easily disturbed by other persons’ attitudes on the one hand and a growing level of independence and adaptive coping over time on the other hand.

The main objective of this study was to examine the prevalence of functional problems in people with SCI in order to get an empirical basis for the decision process on the ICF Core Sets for SCI. Thus, this paper only reports about the basic findings. Further analyses, including subgroup analysis for clinical, demographic and country-specific characteristics, as well as statistical models that allow a closer look at the association between functional problems and environmental factors, could be most interesting.

The limitations of this study relate to the comparison of prevalence detected in the early post-acute versus long-term context. As the prevalence was not adjusted for confounding variables, the differences found may be biased and should be interpreted with caution. Furthermore, countries were not equally represented in the sample. Industrialized countries were overrepresented, and consequently, the external validity of our results may be limited. In addition, the ICF was applied in a restricted way in this study. First, only second-level ICF categories were applied, which brought about a description of functional problems on a relatively low level of specification. Second, the qualifiers, which denote the magnitude of a problem and originally consist of a five-step scale, were transformed to a dichotomous scale indicating only the presence or absence of a problem.

In conclusion, the results of this study indicate that the ICF has potential to be developed as a useful framework to comprehensively describe functional health and disability in people with SCI, but still requires further study and exploration. The most common second-level ICF categories for individuals with SCI were identified in this study and made up the basis for the decision of the ICF Core Sets for SCI, which will facilitate further exploration of the application of the ICF framework in SCI clinical practice and SCI research in future.