Progress of the Dutch Spinal Cord Injury Database: Completeness of Database and Profile of Patients Admitted for Inpatient Rehabilitation in 2015

The International SCI Data Sets Project (ISCIDS) was founded in 2002 to facilitate a common language among SCI centers worldwide.5 Since then, a number of data sets have been developed, published, and made available through the website of the International Spinal Cord Society (http://www.iscos.org.uk/international-sci-data-sets).

All data sets were created according to an established consensus and approval process, which includes receiving comments from all relevant and interested organizations and individuals in an open iterative process.5 Further, in response to the growing international use of the ISCIDS, procedures regarding translation and reliability testing of the data sets were developed to enhance their international utility.6 

In 2001, the first national data collection was developed by the Dutch-Flemish Spinal Cord Society to examine the characteristics of patients with SCI admitted to initial clinical rehabilitation in the Netherlands and Flanders and to facilitate SCI studies. The one-page form contained items on demographic characteristics, SCI characteristics, and functional status, and it was slightly adapted to conform to the International Core Data Set in 2002.7 Results from the data collected in 2002–2007 have been published previously.8 

After a number of other data sets became available, and building on this previous experience,8 the Dutch ISCIDS Database (Nederlandse Dataset Dwarslaesie [NDD]) was initiated as a collaboration between the Dutch-Flemish Spinal Cord Society (DuFSCoS), Heliomare Rehabilitation Center, and De Hoogstraat Rehabilitation. All eight Dutch rehabilitation centers with a specialty in SCI rehabilitation participate in the NDD. The goal of the NDD is to establish a database with standardized clinical information on patients with SCI treated in Dutch rehabilitation centers so that we can (1) increase the knowledge about the epidemiology of SCI in the Netherlands, (2) provide clinical and outcome information useful for quality improvement initiatives, and (3) facilitate research by creating a participant database for future studies. Funding from Rehabilitation the Netherlands (Revalidatie Nederland) through the Innovation in Rehabilitation program was obtained for the period 2012–2014. All data sets available in 2012 were translated and tested for interrater and test-retest reliability. Also, a web-based data-entry platform and database were created. Details of this project and data on reliability of completion of the NDD are provided elsewhere in this issue.9 

The objectives of this article are to describe the current status of the NDD in terms of the number of included patients and completeness of data collected and to use the NDD to provide a profile of people with T-SCI and NT-SCI in the Netherlands.

The NDD collects data on patients admitted for their first inpatient rehabilitation after onset of SCI to one of the eight rehabilitation centers with a specialty in SCI rehabilitation in the Netherlands. Data on patients with a date of admission in 2015 were utilized in the current study, because this was the first full calendar year after the implementation project.

In each rehabilitation center, a staff member, for example, a nurse practitioner or physician assistant, takes care of data collection at each patient's admission and discharge. Data to be collected are retrieved from the medical record (eg, medication for bladder regulation) and the patient is asked about information that is not, or not always, available in the medical record, such as satisfaction with physical health. The degree to which data collectors rely on charts versus patient report varies according to local procedures and preferences. Data collection takes 30 to 60 minutes per patient per time. The rehabilitation physician responsible for the patient supervises this data collection. No immediate feedback concerning completeness or accuracy of data entered in the NDD is provided to the participating centers.

Data collection is facilitated by a web-based data entry platform and database, hosted by a specialized company (Fastguide; www.Fastguide.nl). An individual report of the entered data (patient report) is available in pdf format. Centers can also make exports of data of their patients in Excel format (XLSX, CSV). No personal information (names, addresses) is entered in the national database. Instead, participating rehabilitation centers use a local or a study-specific code number to enter and trace their patients in the NDD. Informed consent varies between centers. In some centers all patients are asked for written informed consent in advance. In other centers patients are informed by oral and written information about the use of anonymous data for research purposes at admission and can decline the use of their data for research purpose, including the NDD.

The translation and consensus procedure to establish the ISCIDS is described in detail elsewhere in this issue.9 In short, we translated all data sets available at the time in accordance with the guidelines for translation of the ISCIDS.4 This included the core data set,7 urinary tract function,10 bowel function,11 cardiovascular function,12 pulmonary function,13 male sexual function,14 female sexual function,15 urodynamic,16 pain,17 skin and thermoregulation,18 quality of life,19 and single items from the autonomic function standards.20 After having translated the core data set7 in full, it was decided to translate only the score forms and variable descriptions, assuming that everyone working with the NDD will sufficiently master medical English to understand the introductory texts and training cases.

Desirable adaptions and additions were discussed with 20 SCI rehabilitation physicians. Adaptations mainly concerned the core data set7 to which variables were added to record the date of first admission to an acute hospital and the date of first admission to the rehabilitation center separately and to record the place of stay before admission to rehabilitation. The variables associated injury, spinal surgery, and ventilator assistance were extended to capture the most frequent types of these injuries, surgery, and assistance, respectively. Further, the variable etiology was extended to capture the most frequent non-traumatic causes and a variable pattern of onset of SCI was added, based on the non-traumatic SCI data set.21 We also shortened the pain basic data set.17 The classification of location of pain was simplified, most pain interference items were omitted, and data were, if applicable, only to be collected on the worst nociceptive and the worst neuropathic pain, instead of on the three worst pain problems.

Finally, three measures were added to the NDD: the Hoffer classification of functional mobility,22 the Walking Index for SCI (WISCI II),23 and the Spinal Cord Independence Measure (SCIM III).24 

Descriptive statistics were used to describe the completeness of the NDD data and demographic and SCI characteristics of the patients admitted in 2015. Chi-square and Mann-Whitney tests were used to compare characteristics of patients with T-SCI to those of patients with NT-SCI.

Data of 424 patients were available. The number of patients per rehabilitation center ranged between 40 and 72. Official figures from the participating rehabilitation centers indicate that a total of 553 patients were admitted for their first rehabilitation after onset of SCI in 2015, meaning that the NDD contains data on 76.7% of this population.

Data at discharge were collected on 310/424 (73.1%) of the patients. Reasons for missing discharge data mainly relate to time constraints. The group with complete data showed no significant differences from the group without data at discharge on the core data set items at admission.

Table 1 provides an overview of available data, as illustrated by the number of valid and missing responses on sample items of each data set. Most complete (>90%) was information on lower urinary tract function, bowel function, pain, cardiovascular function, and skin. Information on quality of life was available for 60.8% and 62.3% of the patients at admission and discharge, respectively. Less information was available on sexual function, in particular, female sexual function, with only 24.3% at admission and 34% at discharge. The number of missing values in demographic and other general characteristics (core data set) was generally low (2–29, or 0.5%–6.8%) (Table 2). ISNCSCI data were complete, meaning they were available at both admission and discharge for 177 (41.7%) of all included patients, and a similar level of completeness was found for the SCIM III (38.0%).

Of the 424 patients, 63.4% were male and their median age at the onset of SCI was 60 years (interquartile range [IQR], 48–69). Two-thirds (65.5%) had NT-SCI. Most patients underwent spinal surgery and the majority had SCI American Spinal Injury Association Impairment Scale (AIS) D. Other characteristics are displayed in Table 2.

Patients with NT-SCI were older and more often were female, admitted from a general hospital, had a lumbosacral lesion, and their lesion showed a gradual onset without vertebral injury and without associated injury. However, in both groups about two-thirds underwent spinal surgery.

Discharge data were available for 310 out of 424 patients (73.1%). This percentage ranged from 37.5% up to 94.4% per rehabilitation center.

The median length of stay in the rehabilitation center of these 310 patients was 76 days (Table 3). The large majority of patients were discharged to their private residence, and most of the others were discharged to a temporary place of stay (eg, to a nursing home) for further rehabilitation or to await domestic adaptations. Type of SCI was AIS D for three-fourths of the patients at discharge.

Patients with T-SCI stayed considerably longer in the rehabilitation center compared to patients with NT-SCI and more often had cervical and complete lesions at discharge. All five patients who died in the rehabilitation center had NT-SCI. Place of discharge did not show a significant difference between both groups (Table 3).

In its first complete year of data collection, 424 patients were entered in the NDD. Data at both admission and discharge were available for 73.1% of the patients in the database. Completeness of data varied strongly. Most problematic in terms of completeness were the male and female sexual function data sets, the quality of life data set, and the ISNCSCI and SCIM III data. Even with incomplete data, however, the NDD shows potential as an evolving national database providing comprehensive clinical information on people with SCI in the Netherlands. Whereas obtaining funding will be conditional to the further development of the NDD, the upside is that we already collect data on the majority of patients. Therefore, we feel our results are encouraging so far.

Strengths of the NDD are its broad coverage and correspondence to the international data sets. Most data sets were straightforward to translate and apply; some variables in the core data set were added to reflect our local situation and application in a mixed T-SCI/NT-SCI population.

The NDD has most of the characteristics of a registry25: It has an inclusion principle, contains mergeable data collected in a standardized way, and has rules for data collection. Data collection at admission and discharge provides a longitudinal perspective, although no post-discharge data are collected to date.

Another strong feature is that the NDD includes patients with T-SCI or NT-SCI. Our first results show that the majority of our current patient population has NT-SCI and that this group strongly deviates from the T-SCI group on a range of demographic and SCI characteristics, confirming results from previous Dutch studies.8 Most SCI databases only include patients with T-SCI,2 and most SCI literature also stems from studies in patients with T-SCI. Although good quality figures are largely lacking, it is clear that the incidence of NT-SCI is already high and is expected to grow.26 Gaining knowledge on all aspects of SCI treatment and outcomes in this patient population is therefore urgent.

Mean age of patients with T-SCI in this study was 8.6 years higher compared to a data collection we performed in the Netherlands and Flanders on similar patients admitted in 2002–2007, showing a mean age of 43.4 (SD = 16.7) years.8 There were, however, no gender differences between both studies. Our mean age at onset of SCI of 52 years is similar to the 52.5 years in the 2009–2013 group in a Scottish study27 and is slightly higher than the 48 years found in a large Swiss study.28 These European figures deviate from the current average age at onset of 42 years in the United States.29 

Our study showed the most important cause of T-SCI to be falls. The proportion we found (56.6%) is high compared to the international literature.30 The high age at onset of SCI and environmental factors such as high levels of traffic safety, low levels of violence, and lack of mountains in the Netherlands may contribute to this difference.

The proportion of patients with cervical SCI (65.7%) was higher than in the previous study (49.6%), and the proportion of patients with AIS A (18.9%) was lower compared to this previous study (37.2%).8 These differences reflect changes in the demography of the SCI population in developed countries.27,30,31 

In contrast to the T-SCI group, the group of patients with NT-SCI in this study was largely similar to this group in our previous study.5 Mean age was only slightly (2.2 years) higher in the current study, and differences in the distribution of gender, level of SCI, and completeness of SCI were below 5%. Etiology of NT-SCI was also similar, but it was difficult to compare due to a diverging categorization of etiology.8 

An international comparison with data on 956 patients from 9 countries (including the Netherlands) with NT-SCI admitted in 2008–2010 showed a similar mean age (59 years) and proportion of males.32 Results from our study did not differ with respect to the high proportions of patients with paraplegia (72.3 in both studies). However, we found a higher proportion of patients with AIS D (64.2% vs 52.4%).32 

Etiology of NT-SCI is difficult to compare because of the wide variation between countries, but the high proportions of degenerative and oncology found in our study reflects the situation in other Western European countries.26 Our study shows a high proportion of “other” etiologies, probably because we did not include a category of benign tumors. This needs to be changed in the future, which would bring our categorization in line with the recently published second version of the core data set.33 

The duration of inpatient rehabilitation of patients with T-SCI was substantially reduced compared to our previous study,8 from median 207 days in 2002–2007 to median 112 days in 2015. This difference can partly be explained by the shift in demographic and SCI characteristics, for example, the lower proportion of patients with complete SCI. However, the duration of rehabilitation in the similar groups of patients with NT-SCI was also shorter in 2015 (65 days) compared to 2002–2007 (109.5 days).8 

The work presented here is still in progress. The NDD is very limited and immature compared to established databases such as the US National SCI Database and the Rick Hansen registry in Canada.34,35 

First, the NDD is not population-based but includes patients treated in specialized rehabilitation centers. Specialized centers may admit on average younger and more severely injured patients.34 This limitation however applies to most SCI databases.2 

Second, so far the NDD only includes patients admitted for their first inpatient rehabilitation after the onset of SCI. We are considering the collection of data on follow-up visits to provide a longitudinal perspective and to expand data collection to non-specialized rehabilitation centers. To date, however, we are giving priority to enhancing the completeness of the current data collection.

Third, other limitations stem from time constraints due to the current lack of external funding for this project. There is no funding for the data collection itself, so it relies on the willingness of the participating centers to spend manpower on this project. Australian experiences have shown that it is possible to maintain a national SCI register at relatively low costs.36 Therefore, we were not able to check the completeness and accuracy of the data collection on a continuous basis. This would probably have resulted in much higher completeness rates of the ISNCSCI and SCIM III in particular, since these data are collected routinely in the participating centers. Also, checks to enhance data quality are important and need to be developed.34,35,37,38 Fortunately, much of these data can be added to the database and checked retrospectively when funding is obtained at a later stage. It proved difficult to develop an error-free ISNCSCI scoring algorithm. Fortunately, better algorithms to compute ISNCSCI scores are available to date and will be used in the future.39 

Fourth, completeness of the sexual function data sets was low. Our data collectors commented that they were reluctant to address this topic and could not retrieve it from medical charts in most cases. It is known that most patients and health professionals are reluctant to address sexuality.40 Quality of life proved similarly difficult to discuss shortly after admission. In response to these comments, we made the collection of data on sexuality and quality of life voluntary at admission, but these were kept as items to collect at discharge.

The NDD is a collaborative effort of all eight rehabilitation centers with a specialty in SCI rehabilitation in the Netherlands. With the NDD, we collect important data on the majority of SCI patients in the Netherlands. However, much work needs to be done to continue the data collection, improve its completeness, and to expand the NDD toward a national SCI register.

The development of the NDD was supported by Rehabilitation Netherlands (Revalidatie Nederland), Innovation in Rehabilitation program, grant IPR2011-12. The authors thank all participating rehabilitation centers and all people involved in the data collection for their support of the NDD. The authors report no conflicts of interest.