From Bad to Worse:
Comorbidities and Chronic Lower Back Pain
®
Margaret Cecere JD, Richard Young MD, Sandra Burge PhD
The University of Texas Health Science Center at San Antonio
John Peter Smith Family Medicine Residency Program, Fort Worth
Introduction
Methods
Chronic lower back pain is the fifth most common reason
for all physician visits and serves as the leading cause of
lost work time and disability, resulting in health care
expenditures of more than $20 billion annually.1 Chronic
lower back pain is a complex condition, which becomes all
the more complicated when the patient also suffers from
associated comorbidities, such as depression, anxiety,
chronic disease, and an elevated Body Mass Index (BMI).2
Previous research has suggested that chronic pain may be
exacerbated in patients with another comorbid diagnosis.3-4
However, little is known of the specific relationship
between chronic lower back pain and these comorbid
conditions. The purpose of this study is to examine the
correlation of chronic lower back pain and general health
with other comorbidities, such as depression, anxiety,
chronic disease, and an elevated BMI.
Results
Subjects. Student research assistants enrolled 367 adult
patients from 9 outpatient clinics across Texas. Patients
had low back pain > 3 months but were excluded if they
were pregnant or had a diagnosis of cancer.
Procedure and Measurement. A 6-page patient survey
addressed demographic characteristics, pain duration,
frequency and severity, physical functioning and general
health, anxiety, depression, substance abuse, and risk for
opioid misuse. Patients reported pain severity using a
10-point scale. From participants’ medical records,
students gathered information about causes of low back
pain, treatments for pain, comorbidities, and BMI. To
assess comorbid conditions, the chart review abstraction
form included a list of chronic illnesses commonly seen
in family medicine. Investigators also evaluated general
health using composite scores based on four items from
the MOS Short Form-36, which addressed general health
(feelings of wellness versus illness). A higher score
indicated better health.
Percent of Patients with Comorbidities
100
90
80
70
60
50
40
30
20
10
0
Participant Demographics. Of
the 367 participants, 71.9% were
female, 29.2% were Hispanic,
22.6% were African American,
and 42.8% were White. The
mean age of participants was
52.91, ranging from 18 to 89. Of
the 273 participants with a high
BMI, 20.5% were overweight
(BMI between 25 and 30) and
52.1% were obese (BMI > 30).
The common comorbid
conditions and the percent of
patients who suffered from each
is illustrated in Figure 1.
Comorbidities. Our findings
demonstrate that participants who
suffered from chronic lower back
pain along with asthma,
depression/anxiety, GI disorders,
or hepatitis C showed a
significant increase in pain
severity (Figure 2). Also
notable, patients with the chronic
diseases of obesity, inflammatory
arthritis, chronic obstructive
pulmonary disease (COPD),
diabetes (DM),
depression/anxiety, hepatitis C, or
hypertension showed
significantly worse general health
(Figure 3). Furthermore, the sum
of comorbid diseases was
correlated with pain severity
(r=.139, p=.008) and
general health (r=-.216, p=.000).
Figure 2: Pain Severity and Comorbidities
8
7.8
7.6
7.4
7.2
7
6.8
6.6
6.4
6.2
6
Diagnosis Absent
Diagnosis Present
P value
Asthma
6.67
7.41
Depression/Anxiety
6.46
7.23
GI Disorder
6.64
7.24
Hepatitis C
6.67
7.98
.020
.001
.021
.000
Figure 3: General Health Deterioration Due to Comorbidities
2.9
2.8
2.7
2.6
2.5
2.4
2.3
2.2
2.1
2
No Diagnosis
Diagnosis
P value
BMI > 30
2.75
2.52
.031
Arthritis
2.66
2.13
Asthma
2.68
2.42
COPD
2.70
2.24
DM
2.69
2.47
Dep/Anx
2.75
2.47
Hep C
2.67
2.28
HTN
2.79
2.51
Person. D/O
2.66
2.24
.035
.072
.003
.054
.007
.032
.008
.073
Conclusions
1. Consistent with previous research, we found a significant relationship between pain severity and several comorbid
conditions such as asthma, depression/anxiety, GI disorders, and hepatitis C.2
2. We also found a significant relationship between general health and the comorbid conditions of obesity, COPD,
inflammatory arthritis, GI disorders, diabetes, hypertension, and hepatitis C.
3. There exists a correlation between pain, health, and the sum of comorbid diseases, which indicates that an increase in
the number of diseases results in more pain and worse subjective health.
4. Clinicians should be aware of the burden of chronic illness, depression/anxiety, and an elevated BMI on the pain and
general health of their patients with chronic low back pain. Clinicians should help patients find activities that they can
perform in the context of chronic pain in order to prevent comorbidities which can escalate chronic lower back pain.
Acknowledgements
References
This study was conducted in the Residency Research Network of
Texas (RRNeT) with support from the Dean’s Office, School of
Medicine, UTHSCSA; the Texas Academy of Family Physicians;
the South Texas Area Health Education Center; the National
Center for Research Resources (Award # UL 1RR025767); and
the Health Resources and Services Administration (Award #
D54HP16444). The content is solely the responsibility of the
authors and does not necessarily represent the official views of
the National Center for Research Resources of the National
Institutes of Health.
1
Rives, P.A., & Douglass, A. B. (2004). Evaluation and treatment
of low back pain in family practice. Journal of the American
Board of Family Practice, 17, S23-31.
2 Hagen, E. M., Svensen, E., Eriksen, H. R., Ihlebaek, C. M., &
Ursin, H. (2006). Comorbid subjective health complaints in low
back pain. Spine, 31(13), 1491-1495.
3 Marcus, D. A. (2004). Obesity and the impact of chronic pain.
Clinical Journal of Pain, 20(3), 186-191.
4 Kuch, K. (2001). Psychological factors and the development of
chronic pain. Clinical Journal of Pain, 17(4 Suppl), S33-8.