Pain and social integration after spinal cord injury
METHODS
Study design and population
The study was designed as an observational, non-interventional,
cross-sectional survey. Inclusion criteria were: age at least 18
years; diagnosis of traumatic SCI at least 3 months prior to
enrolment in the study; being treated at the Department of Re-
habilitated Medicine, and Department of Orthopedic Surgery,
the First Affiliated Hospital of Chongqing Medical University
as inpatients or outpatients from 2012 to 2017. Participants with
neurological function restored normally at the time of follow-up
were excluded. A final total of 318 individuals (242 males and
76 females; mean age 41 years) were included.
Procedures
The data used in this study required no extra clinical tests, or
treatments than those given regularly. The cross-sectional study
was approved by the local ethics committee, in accordance
with the Declaration of Helsinki, and all participants (or their
legal representatives) gave signed informed consent for the
collection, storage and analysis of the data, with guarantees of
confidentiality.
Demographic and clinical characteristics were collected at
either initial hospitalization or follow-up. Data on impairment
level, sex, race, and educational status were collected at initial
hospitalization. Data on pain and social integration were collec-
ted either during face-to-face follow-up or during a subsequent
following phone interview.
Data collection
Demographic characteristics recorded included age, sex, educa-
tional status, mobility status, employment status and relationship
status. SCI characteristics recorded included mechanism of
injury, time since injury, neurological level of injury, and Ame-
rican Spinal Injury Association Impairment Scale (AIS) grade.
Participants were asked about chronic pain, defined as con-
tinuous or daily recurring pain that had been present for > 3
months. Participants with chronic pain rated their mean pain
intensity using the 0–10 numerical rating scale. Pain intensity
scores of 0–3 were classified as mild, 4–6 as moderate, and 7
or more as severe.
Participants rated the extent to which overall pain interfered
with functioning within 7 domains: general activity, mobility,
normal work, relations with others, mood, enjoyment of life,
and sleep, on a numerical rating scale ranging from 0 (no inter-
ference) to 10 (extreme interference) using the modified Brief
Pain Inventory (BPI) (7, 12). The BPI total interference score
was calculated as the mean of the 7 domains; the BPI activity
interference score was calculated as the mean of the following
items: general activity, mobility and work; and the BPI affective
interference score was calculated as the mean of the following
items: mood, relationships and enjoyment of life, while sleep
was assessed separately (13).
The 7-item Douleur Neuropathique 4 Questions (DN4)
questionnaire was used to record whether the reported pain was
neuropathic in presentation (14). The selection of at least 3 of
the 7 pain descriptors (burning, painful cold, electric shocks,
tingling, pins and needles, numbness, and itching) is suggestive
of neuropathic pain (NP) (15).
Social integration was measured with the Social Integration
Index from the Craig Handicap Assessment Reporting Technique
(CHART) (16). However, the current information society is sig-
nificantly different from when the CHART was published. Social
507
integration scores were modified by changing once a month into
once every 2 weeks. The CHART social integration index is a
6-domain instrument that is commonly used to quantify the effects
of injuries and other conditions on activities of daily living. Each
domain is scored on a 100-point scale, with a score of 100 repre-
senting a level of performance typical of a non-disabled person.
The CHART Social Integration Index was skewed, with 77%
of participants having a score of 80–100. The classification
method of Roach MJ was used, through which the index was
transformed into a 3-category social integration measure (low
0–50; medium 51–79; high 80–100) (17). This categorization
was based on the distribution of CHART scores. At scores of
51 and 80, there was observable separation of participants, and
therefore these scores were used as categorization cut-off points.
Statistical analysis
Participant characteristics were reported using descriptive sta-
tistics. Continuous variables were expressed as means (standard
deviations (SD)) and categorical variables as numbers and per-
centages. Comparison of categorical variables (pain locations,
pain descriptors, pain intensity category in SCI individuals with
nociceptive and NP) were conducted using the χ 2 test or Fisher’s
exact test, as appropriate. Numerical data (BPI interference
score between nociceptive pain and NP) were analysed using
an unpaired t-test or the Mann–Whitney U test, as appropriate.
For comparisons of CHART social integration scores between
3 groups (participants with no pain, NP, and nociceptive pain)
1-way analysis of variance (ANOVA) was used with Bonferroni
multiple comparison tests to analyse the differences in CHART
social integration scores outcome. Binary logistic regression,
Spearman’s correlations and linear regression was used to
analyse the factors associated with different pain types and the
relationships between pain and social integration measures.
Data were analysed using IBM® SPSS® statistics software,
version 24 (IBM SPSS Statistics for Mac, version 24.0., IBM
Corp., Armonk, NY, USA). A p-value < 0.05 was considered
statistically significant.
Statement of ethics
The authors certify that all applicable institutional and go-
vernmental regulations concerning the ethical use of human
volunteers were followed during the course of this research. The
ethics committee of the First Affiliated Hospital of Chongqing
Medical University approved the study (2018019).
RESULTS
Patient characteristics
Of 403 individuals with SCI who were screened, 351
were recruited and contacted. A total of 318 surveys
were completed and returned (response rate 91%).
The age range was 19–77 years, mean age 41 years
(SD 13); 242 participants (76%) were male, and 76
(24%) were female. The most common causes of
traumatic SCI were other traumatic (composed mainly
of collision with falling objects and being crushed by
heavy objects) in 126 (40%), followed by falls (35%)
and motor vehicle accidents (20%). Most injuries were
reported as incomplete. The most common neurologi-
J Rehabil Med 51, 2019