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International Journal of Orthopaedics Sciences 2016; 2(4): 171-175
ISSN: 2395-1958
IJOS 2016; 2(4): 171-175
© 2016 IJOS
www.orthopaper.com
Received: 15-08-2016
Accepted: 16-09-2016
Dr. Kalyan Kumar Varma
Kalidindi
MS Orthopaedics Jipmer,
Pondicherry, Tamil Nadu, India
Dr. DK Patro
Senior Professor, Department
of Orthopaedics Jipmer,
Pondicherry, Tamil Nadu, India
Dr. Deep Sharma
Associate Professor, Department
of Orthopaedics Jipmer,
Pondicherry, Tamil Nadu, India
Correspondence
Dr. Kalyan Kumar Varma
Kalidindi
MS Orthopaedics Jipmer,
Pondicherry, Tamil Nadu, India
Significance of sub grouping patients with chronic low
back pain in management decisions: A prospective
study
Dr. Kalyan Kumar Varma Kalidindi, Dr. DK Patro and Dr. Deep Sharma
DOI: http://dx.doi.org/10.22271/ortho.2016.v2.i4c.30
Abstract
Background: The Quebec Task Force classification (QTF) was originally designed to help in
making a clinical decision and to aid in determining the prognosis. However, the predictive
validity and prognostic significance of the classification was debated.
We conducted the study to determine the discriminative and prognostic significance of the
modified Quebec Task Force classification in chronic low back pain patients
Materials & Methods: 183 consecutive chronic low back pain(>7 weeks of continuous pain)
patients in the age groups of 18-65 years who presented to a tertiary care centre in South India
and followed up for a minimum of 6 months were included in the study. Patients were
assigned to one of the four QTF categories after a detailed history and examination. Pain
severity and functional disability were assessed using LBPRS and RMDQ respectively. The
patients were then put on the common specific rehabilitation protocol and analgesics, and
followed up every six weeks to look for compliance with the treatment. The scores (LBPRS,
RMDQ) were noted again at 3 and 6 months. The comparison of scores was done among the 4
QTF categories at the time of presentation, at 3 months and at 6 months
Result: There were no significant differences in the distribution of age, sex, occupation or
educational status among different QTF categories. Non-parametric tests using Wilcoxon
Signed Rank test showed significant improvement in LBPRS and RMDQ scores with time in
each category(p value <0.001).On LBPRS scale, QTF 1 improved the most from baseline after
6 months (42.3%). QTF 4 improved more (24.6%) compared to QTF 2(21.58%) and QTF
3(19.87%).On RMDQ scale, Category 1 and 4 improved more (20.35% and 20.82%
respectively) compared to category 2 and 3(11.81% and 9.1% respectively).
Conclusion: All the four QTF categories showed a significant improvement of pain and
activity limitation from the baseline at the end of 6 months with the physiotherapy
rehabilitation. However, patients with nerve root signs treated non-surgically had a better
outcome compared to those with radiating pain with no nerve root involvement. Patients with
radiation below the knee and negative nerve root signs had the worst outcome in terms of pain
and activity limitation at the end of six months. It validates the QTF classification as a
prognostic label in patients treated with physiotherapy.
Keywords: Quebec task force (QTF) classification, chronic low back pain, prognosis
1. Introduction
Low back pain (LBP) despite having a high prevalence, remains poorly understood and
inadequately treated. It is a major cause of disability and an important driver of health care
costs all over the world. It is already well established that patients with radiating pain to the
leg have a poorer prognosis than patients with LBP alone [3]. This is reflected in the number of
different management guidelines for LBP, which differentiate non-specific LBP, nerve root
pain and serious spinal pathology. However, the current guidelines suggest that patients with
radiating leg pain should be managed in the same way as those with non-specific LBP. The
Quebec Task Force (QTF) report in 1987 suggested distinguishing between pain referral
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International Journal of Orthopaedics Sciences
above, below the knee and those with nerve root pain [4]. Other
studies [5, 6] have also shown that patients with positive
neurological signs have more symptoms, higher psychological
distress and more health care utilization than those without
neurological signs/symptoms. Quebec task force classification
system has received the widest review among various
classification systems that could guide clinical management
decisions or predict pain and disability, but it has some
limitations. The predictive validity of the classification is
debated. Classifying patients as described by the Quebec Task
Force has shown associated differences on a number of clinical
characteristics that display an increasing severity from patients
with local low back pain, across the categories of leg pain
above the knee and below the knee to patients with
neurological signs [5]. These subgroups have also been reported
to differ in outcomes of pain, activity limitation [7] and work
loss [8]. The results of the outcome, however, are conflicting.
Atlas et al. [7] stated that non-surgically treated patients with
nerve root compression had greater improvement than those
with pain symptoms alone after adjustment for baseline
variables. O'hearn et al. in 1997, however, stated that patients
with lower extremity pain had poorer outcomes after physical
therapy treatments [9]. This accords with studies by Andersson
et al. [10], Van der Weide et al. [11], Cherkin et al. [12], Loisel et
al. [8], Nyiendo et al. [13] and Hill et al. [14]. Hill et al. stated that
baseline factors accounted for differences between subgroups
which is in contrast to the findings of Nyiendo et al. Kongsted
et al. [15] in 2013 reported that patients with LBP +
neurological signs had the most severe limitation at all time-
points but improved the most. Overall, a number of conflicting
studies have been reported in a quest to provide proper
management of LBP patients by dividing them into subgroups.
This study has been taken up to study the Modified Quebec
Task Force classification of low back pain and its
discriminative validity. It attempts to predict the changes in
pain and disability on follow-up in different QTF categories.
This study also tries to assess the efficacy of the common low
back pain rehabilitation protocol in various subgroups of
Quebec Task Force classification. To the best of my
knowledge, such a study had not been done in a tertiary care
centre in a rural setting in South India.
2. Materials and Methods
The present study was conducted in the department of
Orthopaedic surgery in JIPMER, a tertiary care centre in south
India between October 2013 and June 2015. The patients who
were present to the outpatient department with complaints of
low back pain and satisfying the inclusion and exclusion
criteria were included in the study after taking informed
consent.
2.1 Inclusion criteria
Age group: 18 to 65 years Chronic low back pain patients (>7
weeks of continuous pain) Patients without neurological
deficits/with mild static neurological deficits
2.2 Exclusion criteria
Pregnancy Previous spinal surgeries Progressive/severe
neurological deficits No informed consent Compliance cannot
be assured Surgically curable causes of low back pain and
patient are willing for surgery Abnormal x ray findings (other
than non-specific degenerative changes) or ESR >20 mm/hr
The severity of low back pain was measured using the pain
domain of the Low Back Pain Rating Scale
(LBPRS).Disability because of low back pain was calculated
using the Roland Morris Disability Questionnaire
(RMDQ).After completing the history and examination,
patients were advised plain x rays (anteroposterior and lateral)
of the lumbar spine and blood was collected for calculating the
erythrocyte sedimentation rate. If abnormalities in x rays
(other than degenerative changes on lumbar imaging which are
considered non-specific as they correlate poorly with
symptoms) or erythrocyte sedimentation rate (>20 mm/hour)
were detected, patients were excluded from the study and
investigated for specific causes of low back pain.
Patients were then placed into one of the four QTF categories
as follows
MODIFIED QTF CLASSIFICATION:
Category 1: Local LBP only
Category 2: LBP + pain above knee
Category 3: LBP + pain below knee
Category 4: LBP with signs of nerve root involvement (LBP +
NRI)
They were put on the common rehabilitation protocol. The
patients were advised to follow every 6 weeks to check for the
progression of symptoms clinically and for the compliance
with the rehabilitation protocol. The patients were advised to
report earlier in the case of worsening of neurological deficits.
The compliance with the rehabilitation protocol was assessed
by asking the patient to demonstrate the exercises in front of
the investigator and enquiring the attendants about the
patient’s compliance separately The patients were evaluated at
3 months and at 6 months.Patients whose pain symptoms
varied at a later presentation (change category according to
Quebec Task Force classification) were included in the
category at the time of his first presentation at the time of
analysis.
3. Results
The present study was a prospective study conducted in
JIPMER, a tertiary care centre in south India from October
2013 to June 2015 with a follow-up period of 6 months.
209 consecutive and consenting patients presenting with
chronic low back pain to the department of Orthopaedics were
recruited after satisfying the inclusion and exclusion criteria,
out of which 183 patients who were followed up for a
minimum of 3 months were included for analysis. Among
them, 172 patients (82%) were followed up for 6 months.
None of the baseline characteristics (age, sex, educational
status and occupation) measured had shown a significant
difference in the distribution among various QTF categories.
The comparison of LBPRS scores is done adjusting the score
of QTF 1 category to fit comparison with other categories. The
mean LBPRS score at the time of presentation was 30.05+/-
9.19 in category 1, 34.09+/-6.84 in category 2, 37.33+/-7.9 in
category 3, and 48.36+/-7.36 in category 4.There was an
increasing severity of pain from category 1 to category 4 as
measured by LBPRS scores. At any point in time, QTF 4
category had the highest severity of pain.
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International Journal of Orthopaedics Sciences
Table 1: LBPRS scores in varrious QTF categories at presentation, 3 months and 6 months
LBPRS QTF Cat
Cat I Cat II Cat III Cat IV
Presentation 30.05±9.2 34.09±6.84 37.33±7.90 48.36±7.37
3 months 21.56±8.6 29.23±6.70 33.31±10.22 41.38±8.74
6 months 17.32±8.07 26.73±7.47 29.91±9.75 36.47±10.2
Change (% Improvement from baseline)
3 months 8.4(28.3) 4.9(14.25) 4(10.76) 7(14.47)
6 months 12.7(42.3) 7.4(21.58) 7.4(19.87) 11.9(24.6)
P value from baseline
3 months <0.001** <0.001** <0.001** <0.001**
6 months <0.001** <0.001** <0.001** <0.001**
The differences in LBPRS scores among the QTF categories at
all points of time (at presentation, 3 months and 6 months)
were statistically significant (p-value <0.001).
Non-parametric tests using Wilcoxon Signed Rank test
showed significant improvement in LBPRS scores with time in
each category of QTF classification with P values <0.001.
QTF category 1 patients improved the most after 6 months
(42.3% improvement from baseline) followed by QTF
category 4 patients who improved 24.6% from the baseline.
QTF 3 patients improved the least with 19.87% improvement
from baseline and QTF 2 patients improved 21.58% from the
baseline. These differences in improvement from baseline
were statistically significant with p-value <0.001. These values
were calculated using ANOVA test for calculation of
differences between groups and student t-test for calculation of
differences within the groups.
Patients in category 4 had the most severe functional limitation
on RMDQ with a mean of 16.57+/-3.13 at the time of
presentation. The next more severe limitation was in patients
with radiating pain below knee with a mean of 14.5+/-
3.68.category 2 patients had a mean of 13.3+/-4 and category 1
patients had a mean of 11.36+/-3.11.
Category 4 had the highest functional limitation as measured
by RMDQ scores at the time of presentation and at 3 months.
At 6 months, however, category 3 and 4 had high activity
limitation compared to the other two groups.
Table 2: RMDQ scores in various QTF categories at presentation, 3 months and 6 months
RMDQ QTF Category
Cat I Cat II Cat III Cat IV
Presentation 11.36±3.11 13.30±4.00 14.50±3.68 16.57±3.13
3 months 10.31±3.21 12.44±3.88 13.27±4.20 15.11±3.58
6 months 8.21±4.35 11.73±4.25 13.18±4.97 13.12±3.99
Change (% Improvement baseline )
3 months 1.05(9.24%) 0.86(6.46%) 1.23(8.48%) 1.46(8.81%)
6 months 3.15(20.35%) 1.57(11.81%) 1.32(9.10%) 3.45(20.82%)
P value from baseline
3 months 0.006** <0.001** 0.007** 0.010**.
6 months <0.001** <0.001** <0.001** <0.001**
At 6 months follow-up, Category 4 patients improved the most
with 20.82% improvement from a baseline mean score
followed by category 1 patients with 20.35% improvement
from baseline. Category 2 and 3 patients had less improvement
compared to other categories. Category 3 patients were the
least improved among the 4 categories with 9.1%
improvement from baseline followed by category 2 patients
with 11.81% improvement. Category 3 had no significant
improvement in the functional limitation on RMDQ after 6
months. Other 3 categories had significant improvement in
functional limitation after 6 months with p-value
<0.001.Category 1 was least affected by activity limitation oth
at baseline ans at the end of 6 months. The comparison of
RMDQ scores between the groups was done using ANOVA
test, and comparison of scores within the group was done
using the Student t test.
4. Discussion
We found that all the subgroups of patients showed significant
improvement in symptoms at the end of 3 and 6 months with
the physical rehabilitation. Patients in category 4 scored more
in terms of pain severity than category 3 which in turn scored
more than 2 and category 1 had the least score at the end of 6
months. However, in terms of percentage improvement from
baseline, QTF category 1 patients improved the most after 6
months (34.28% improvement from baseline). QTF category 4
patients improved 24.6% from the baseline which was more
when compared to the improvement in QTF categories 2 and
3. QTF 3 patients improved the least with 16.98%
improvement from baseline and QTF 3 patients improved
19.87% from the baseline. Significant differences were found
in the QTF categories irrespective of age, sex and educational
status. Di Fabio et al. in his non-randomised study reported
outcomes post physiotherapy intervention where patients with
LBP and leg pain improved but still scored higher on LBP
disability at 1 month and at discharge compared to patients
with LBP alone. Nyiendo et al. presented pain and disability
outcomes after interventions and reported that patients treated
by chiropractors and physicians improved overall with those of
LBP and leg pain below the knee improving less than patients
with LBP alone or with leg pain to the knee.
We found increasing degree of activity limitation at baseline
from category 1 to category 4. Hill et al. and Ben Debba et al.
found that patients with LBP with radiation below the knee in
the secondary care setting tended to be more severely affected
than those with pain with radiation above the knee. Alice
Kongsted et al. stated that patients with pain below knee
revealed higher leg pain intensity and more activity limitation
but little differences in other parameters. Atlas et al. assessed
the discriminative validity of the QTF categories in a chronic
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population and concluded that baseline functional status
assessed by back-specific Roland scale or the generic SF-36
was not strongly associated with QTF category. However, he
used 6 categories of QTF classification and found a severe
profile for patients with sciatica than those with spinal
stenosis. Significant differences in baseline activity limitation
using the RMDQ was found across the 4 subgroups by Alice
Kongsted et al. with category 4 having the most severe profile.
We found that the QTF category 1 had the least activity
limitation at any time point. Pairwise comparisons using
independent t-test showed that there was no significant
difference (2 tailed) between category 2 and 3 at baseline
whereas significant differences were observed between
category 1 and 2 and between category 3 and 4. This is similar
to the findings of Alice Kongsted et al. In terms of outcomes,
we found improvement in the functional status in all categories
of QTF classification by the physical rehabilitation protocol.
At 3 months follow-up, in terms of percentage improvement,
we found that category 1 had the most improvement followed
by category 4. However, at 6 months follow-up, we found that
QTF category 4 patients improved the most among all QTF
categories followed by category 1. Category 2 and 3 had the
least improvement in terms of percentage improvement from
baseline. Nyiendo et al. and Ben Debba et al. reported that
patients with LBP alone (category 1) and LBP with radiating
leg pain to thigh (category 2) were relatively similar in terms
of outcomes, whereas Selim et al. [18] reported similar
outcomes in measures of pain and functional disability for
patients with leg pain radiating to the thigh (category 2) and
below the knee (category 3). We did not find significant
differences in the RMDQ scores between category 2 and 3 at
baseline. This is similar to the findings of Kongsted et al. who
found in his study that category 2 and 3 patients did not differ
significantly in terms of activity limitation at any time point.
Category 4 patients improved more on RMDQ scores (activity
limitation) measured as percentage improvement from baseline
compared to the other groups. Category 1 patients were the
least affected of all the groups in terms of mean RMDQ scores
at any time point but showed significant improvement with
physical rehabilitation in 6 months compared to category 2 and
3. This finding has been observed in previous studies by Atlas
et al. who first reported the greater improvement in functional
limitation of patients managed non-surgically as the QTC
category increased from 2 to 4. Loisel et al. found that QTF
categories 3 and 4 presented a worse prognosis than QTF 1
and 2. They had lower functional status and higher pain level
at the one-year follow-up assessment. However, Loisel et al.
combined category 1 and 2, and category 3 and 4, which might
account for the differences. Alice Kongsted et al. also found
larger improvement in category 4 patients compared to those
in other categories.
5. Summary and Conclusions
5.1 Summary
Our study was conducted in a tertiary care centre in South
India and attempted to assess the pain, disability and global
perceived effect in chronic low back pain patients belonging to
various subgroups of the modified QTF classification. We
assessed the ability of the modified QTF classification to
distinguish among various subgroups of patients. We followed
them with a common rehabilitation protocol and investigated if
the sub-grouping of patients using the modified QTF
classification had any prognostic implications.183 patients,
who followed up for a minimum of 3 months were included in
the study and were assigned one of the four QTF categories
(LBP alone in category 1, LBP with radiation above knee in
category 2, LBP with radiation below knee in category 3, LBP
with radiation below knee + nerve root signs in category 4)
based on the symptoms and signs at presentation. There were
no significant differences in the baseline characteristics like
age distribution, gender, educational status and occupational
status in the four categories of the QTF classification.
Significant differences were observed in the assessment of
pain severity using the pain component of LBPRS in the four
QTF categories. Category 1 had the least severe and category 4
had the most severe pain intensity at all points of time.
Significant differences were also noted in the pain intensity
between category 2 and category 3 with category 3 more
severely affected. Assessment of activity limitation using
RMDQ showed that category 4 patients had the most severe
functional limitation at baseline evaluation. Category 1 had the
least severe activity limitation based on the mean RMDQ
scores. However, no significant difference was found between
category 1 and 2 at baseline evaluation. Similarly, there was
no significant difference in the activity limitation between
category 2 and 3.Comparing the issue of prognosis at 6 months
follow-up, category 1 had improved the most on pain severity
scale using LBPRS followed by category 4. Category 2 and 3
had less improvement after 6 months on LBPRS scores with
category 3 having the least improvement. Category 1 and 4
had more improvement in the functional limitation using
RMDQ compared to category 2 and 3. Category 3 had the least
improvement in mean RMDQ scores from baseline at 6
months follow-up. Category 1 had the greatest percentage
improvement in the mean analgesic score from baseline
followed by category 4. Category 2 and 3 had lesser
improvement compared to category 1 and 4.
There were limitations to our study. The data was essentially a
tertiary hospital based data. It may not represent the extent of
its application to the community and other level hospital care
systems as the population may not be representative.it may be
possible that patients with LBP alone are presented much later
than patients with LBP with nerve root signs. Loss of follow
up of patients and unequal distribution of the study population
into the four categories might have influenced the outcome.
5.2 Conclusions
The modified QTF classification can be used for
differentiating patients on the basis of pain severity or
functional disability at the time of initial evaluation with
increasing severity of pain and functional limitation from
category 1 to category 4.
With regard to prognosis, all the four QTF categories showed a
significant improvement of pain and activity limitation from
the baseline at the end of 6 months with the rehabilitation with
physiotherapy. However, patients with nerve root signs treated
non-surgically had a better outcome compared to those with
radiating pain with no nerve root involvement. Patients with
radiation below the knee and negative nerve root signs had the
worst outcome in terms of pain and activity limitation at the
end of six months.
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International Journal of Orthopaedics Sciences
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