Which factors have an association to the Quality of Life (QoL) of people with acquired Spinal Cord Injury (SCI)? A cross-sectional explorative observational study | Spinal Cord

Current knowledge about Quality of Life with SCI

The life expectancy of patients after SCI has increased significantly almost everywhere in the world due to better acute medical care, although there are still large international differences [1]. For this very reason, a good acute and rehabilitative care including life-long treatment under consideration of the quality of life are becoming increasingly important.

While economic evaluations typically embrace health maximization as the maximization objective, using quality-adjusted life years, there is increasing interest in measuring capability well-being and subjective well-being for informing policy decision-makers [2].

In recent years, there have been a large amount of studies that have looked at, among other things, the impact on the quality of life of people with SCI. Only a few of the more newer ones can be named here as examples that attempt to reflect the state of knowledge. Factors that seem to have a particularly high association are pain and spasticity [3,4,5,6], as well as bladder and bowel function [7,8,9]. Sexual dysfunction also seems to have an association to QoL [6, 10, 11].

Studys and already meta-analysis showed the high impact to QoL of the psychological aspects. Greater acceptance of SCI, life satisfaction, level of depression and anxiety have associations to QoL [6, 12,13,14,15,16]. A great influence on the mental status seems to have the participation in social life [6, 16].

Healthy SCI individuals tend to have better QoL measures and secondary health issues after SCI are affecting QoL and social participation [17]. Older studies, but also very recent ones, confirm that the quality of life of adults with chronic SCI was lower compared with reference populations [6, 18].

In the past, it was already regretted that there was no single definition of Quality of Life that everyone agreed upon, largely due to the breadth of literature that addressed this topic and the varying definitions used in studies [19]. This, too, makes it difficult to compare results between populations or different states. International research projects such as InSCI could help to ensure that there is a uniform definition at some time.

International background

Both the United Nations (UN) and the World Health Organization (WHO) demand the collection of internationally comparable data on the living and care situation of people with disabilities [20]. Consequently, the International Spinal Cord Injury Survey (InSCI) was launched, headed by the International Spinal Cord Society (ISCoS) and the International Society of Physical and Rehabilitation Medicine (ISPRM), within the framework of the WHO Collaboration Plan and the coordination of Swiss Paraplegic Research (SPF). The aim of the InSCI is for health systems to learn from each other through the comparison of results of the 22 participating countries in all 6 WHO regions. The outcomes should also help to develop recommendations for decision-makers in politics and health care [21]. Furthermore, reliable national data are also required to ensure optimal care and supply [22]. Germany is one of the participating countries to collect these requested data to compare within InSCI. In Germany the project is called “German Spinal Cord Injury Survey (GerSCI)”.

One special advantage of the InSCI survey is, that the persons concerned are asked about their point of view and their perceived situation. Therefore, this data collection is particularly suitable for the analysis of the factors potentially influencing perceived Quality of Life (QoL).

Special aspects of this study

One of the first results of the GerSCI study was that, for persons with SCI, QoL decreased with increasing experience of barriers. Some of these aspects have already been highlighted by our study group [23], but it became clear that for this important topic of QoL a specific analysis of the different probably influencing factors was necessary. Therefore, we wanted to look at the different factors individually and try to put them into a clinical context.

In literature, a number of comprehensive questionnaires to assess QoL are available. They are based on diverse constructs of QoL and focus mainly on health-related performance in daily life. Another approach refers to a more general feeling of the subjective perception of life quality. Of course, subjective perception has multiple dimensions but also is related to the individual’s values and life goals. For pragmatic reasons and because the use of complex and extended questionnaires in our study would have led to be not user-friendly we decided to use a commonly used single question to get a rough estimate of subjective level of QoL. The evaluation of separate components and the differentiation between various constructs of functioning should be the subject of future studies.The specific aims of this study were: (i) to describe the level of Quality of Life in the German study population and (ii) to identify and describe the probability of influence on covariates of Quality of Life. (iii) to provide a basis for international comparison within InSCI.

Methods

The German Spinal Cord Injury Survey (GerSCI) data set, as the German part of InSCI, served as the basis for the study. The used questionnaire was developed centrally by the InSCI study group and is thus binding for all InSCI participating countries. It has been shown, that the successful implementation of the InSCI survey enables the comparison of the situation of individuals with SCI in different regions around the world and constitutes a crucial starting point for an international learning experience [24]. GerSCI was implemented in 2017 and was conducted by the Department of Rehabilitation Medicine at Hannover Medical School.

Inclusion criteria:

• Presence of acquired SCI (traumatic or non-traumatic)

• Age ≥ 18 years

• Completed post-acute rehabilitation: 12 months after the onset of the spinal cord lesion

• Current place of residence: Germany, language competence: German

Exclusion criteria:

• Congenital SCI or neurodegenerative diseases

From the database of the eight participating specialized SCI centers, 5,598 potential

participants were identified. They were treated at least once in one of these specialized SCI clinics inpatient or outpatient. They received an invitation letter and the questionnaire, which they could answer in paper form or electronically. After the exclusion of questionnaires that failed to satisfy the inclusion criteria, the available participant data declined by n = 79. Some were excluded due to aborted online questionnaires (n = 56), received duplicate questionnaires (n = 2) and > 30 % of missing values (n = 138). 1479 questionnaires were considered for data evaluation [25].

The potential influence of various factors on QoL were studied using measurements of association.

Survey instruments

Measuring quality of life (WHOQoL-BREF)

The WHOQoL-BREF is an instrument for recording subjective QoL. It is based on the definition of QoL, as the perception of one’s own life situation in the context of respective culture and value systems, as well as in relation to individual goals, expectations, and interests. We use the term QoL to refer to the perceived, purely subjective experience of the participants, in order to reflect their individual perspective in this study. We relate this statement to perceived barriers and enabling factors. The WHOQoL-BREF questionnaire consists of 26 items that focus on several dimensions, such as physical well-being, psychological well-being, social relationships, and environment [26]. Six items were used from the WHOQoL-BREF in the GerSCI questionnaire. These items were predetermined by the InSCI study group. Since there is no reliable sum score of this question selection given by the InSCI team, we chose the overall QoL assessment as the primary target criterion. However, regarding this study, the item which was used for associations as the main parameter was, “How would you rate your quality of life in the last 30 days?”, which were rated on a scale with five ratings from “very poor” to “very good”. Since not the complete WHOQoL-Bref was used in this questionnaire, we were able to create the WHOQoL-Bref global domain score with the first and second question using a scale transformation (0–100). This scale transformed global domain values were then compared to the general population in the year 2000 according to Angermeyer et al. [27]. Unfortunately, no matched and more recent comparison sample is available from Germany.

Covariates

The selection of the covariates within the framework of the InSCI questionnaire was made based on the literature reports described in the introduction and expert discussion within the GerSCI team about possible additional relevant factors. In order to analyze for associations, sociodemographic data and lesion characteristics were used, including age, gender, relationship status, level of injury (paraplegia vs tetraplegia), injury severity (complete vs incomplete), time since injury, etiology (traumatic vs non-traumatic), satisfaction with community health services (satisfied vs not satisfied), difficulties gaining medical aids (no vs yes), employment status (unemployed vs employed), education level (low vs high), net household income (under average vs over average) and health conditions (no vs yes: sleep problems, bowel dysfunction, sexual dysfunction, contractures, decubitus, urinary bladder function, bladder infection, spasticity, respiratory problems, injuries due to sensory disorders, circulatory problems or circulatory disorders, dysreflexia, orthostatic hypotension, diabetes mellitus, periarticular ossification), and pain (no to mild, and moderate to severe).

The five rating categories of the WHOQoL-Bref were dichotomized into “0”, which corresponded with “very bad”, “bad” and “mediocre” and “1”, which corresponded with “well” and “very good”. The pain-scale with rating categories 0 to 10 was convertes in a dummy variable according to Ledowski et al. in 0–3 = no to mild pain and 4–10 = moderate to severe pain [28]. Education status was converted in a dummy variable as 1 = no school leaving certificate, primary school certificate, lower secondary graduation, secondary school graduation, and 2 = advanced technical college entrance qualification, Abitur (general university entrance qualification). Satisfaction with community health service was converted in a dummy variable as 1 = “very satisfied”, “satisfied” and 2 = “neither” or, “unsatisfied”, “very unsatisfied”. Net household income was categorized into 1 = “less than 981 €, 982–1345 €, 1346–1660 €, 1661–1990 €, 1991–2339 €, 2340–2732 €, 2337–3195 €”, and 2 = “3196–3819 €, 3820–4837 €, more than 4838 €” according to average monthly net income per private household in Germany [29]. Problematic health conditions during the last three months were rated on a 5 point Likert scale from “not problematic” until “extremely problematic”. In this analysis, we dichotomized the scale in 0 = “no problem” and 1 = “a little problematic” till “extremely problematic”.

Statistical analysis

Sociodemographic data and SCI characteristics were presented as percentages or means with standard deviation (SD). The key focus of this study was the QoL of people with SCI in Germany. WHOQoL-Bref frequencies were presented as percentages. Only the data from participants with less than 30% missing values were included in the statistical analysis.

To analyze associations between QoL covariates, associations using Eta and Cramers’V were calculated.

The determinants of QoL covariates associated with the perception of a high quality of life were assessed using multivariable logistic regression and estimated odds ratios (OR) with a 95% Confidence interval (CI). Variables were included if they showed significant associations to QoL, which were all variables except marital status.

The proportion of missing values was less than 5%, therefore no imputation of missing values has been performed.

Results were considered statistically significant if p values were less than 0.05. Statistical analyses were performed with SPSS IBM 26.0.