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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Are early somatosensory abnormalities after back pain a biomarker for chronic pain?
Scientific title
Do somatosensory abnormalities predict non recovery in patients with acute low back pain?
Secondary ID [1] 285837 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Low back pain with or without leg pain 293650 0
Condition category
Condition code
Musculoskeletal 293947 293947 0 0
Other muscular and skeletal disorders
Physical Medicine / Rehabilitation 294436 294436 0 0

Study type
Patient registry
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
In this observational study, participants will be assessed first within 3 weeks from onset of low back pain. The assessment will take approximately 2 hours and it will involve baseline data collection, questionnaires administration and quantitative sensory testing (QST). In addition, an evidence-based booklet of basic advice on the management of low back pain that aligns with practice guidelines ("The Back Book") will be provided to all participants. Data collection will include:
- Extent of recovery (Back Pain Recovery Scale);
- Pain intensity (0-10 VAS pain scale);
- Self-reported functional status (Functional Rating Index Scale);
- Self-reported disability (Roland Morris Disability questionnaire);
- Sensory and affective dimensions of pain (Short-From McGill Pain questionnaire);
- Neuropathic pain screening (PainDETECT questionnaire);
- Psychological features (Pain-Self Efficacy questionnaire (PSEQ), Depression, anxiety and stress (DASS-21), Pain catastrophizing Scale (PCS)).

QST assessment will be performed by one trained physiotherapist blinded to participants' condition using standardized protocols and it will include the following tests: cold and heat pain threshold, wind-up ratio, pressure pain threshold, two-point discrimination threshold, thermal temporal summation, conditioned pain modulation (CPM). QST measures will be taken at the back bilaterally (cold and heat pain threshold, wind-up ratio, pressure pain threshold, two point-discrimination threshold) and from the left hand as a remote control site (cold and heat pain threshold, wind-up ratio, pressure pain threshold). Thermal temporal summation will be tested on the palmar surface of the hand. CPM will be performed using a cold bath as a conditioning stimulus and two test stimuli, heat pain and pressure pain.

Participants will be reassessed after 2 months and 4 months. In these sessions, QST measurements and clinical information (e.g. questionnaires) will be collected.

Participants will be contacted at 6 months after LBP onset to attain pain scores and recovery status.
Intervention code [1] 290727 0
Not applicable
Comparator / control treatment
QST data from healthy controls will be attained for comparison at three time points (baseline assessment and after 2 months and 4 months). QST measurements will be performed in the same manner as for participants with low back pain.
Control group

Primary outcome [1] 293763 0
Extent of recovery (Back Pain Recovery Scale)
Timepoint [1] 293763 0
4 months and 6 months from onset of low back pain
Secondary outcome [1] 311778 0
Pain intensity (0-10 VAS pain scale)
Timepoint [1] 311778 0
4 months and 6 months from onset of low back pain
Secondary outcome [2] 311779 0
Functional level (Functional Rating Index)
Timepoint [2] 311779 0
4 months and 6 months from onset of low back pain

Key inclusion criteria
At least 18 years of age; low back pain with or without leg pain; pain duration within 3 weeks from onset; average pain intensity over the last few days at least 3 on a 11-point Numeric Pain Rating Scale.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Signs or symptoms of serious spinal pathology (e.g. tumor, infection, fracture); any pain condition in the past year that has lasted for >1/12 and affected daily function or work activity; diagnosed co-morbid pain syndrome (e.g. fibromyalgia, irritable bowel syndrome, osteoarthritis); medical condition known to affect the nervous system (i.e. neurological disease, diabetes); previous lumbar surgery; pregnancy; unstable psychiatric disorder; substance abuse; severe cognitive impairment (arising from head injury or other comorbidity); long term use of medications that may impact on cognitive or sensory function (e.g. opiates greater than daily morphine equivalent 40mg); unable to read, write and understand English.

Study design
Natural history
Case control
Statistical methods / analysis
Sample size: There appear to be no other published studies that used the Back Pain Recovery Scale, the primary outcome employed in this project, with QST measures. As such the sample size calculation is not trivial as we do not know what effects to anticipate. The closest available outcome in chronic low back pain used either a numerical rating scale (NRS) or visual analogue scale (VAS) for level of pain with correlations ranging between 0.01 and 0.46 for various QST measures. This level of correlation equates to negligible to moderately large effect sizes (Cohen J (1988). Statistical Power Analysis for the Behavioral Sciences). The main interest of this project is to explore the relationship between QST measures and the Back Pain Recovery Scale using regression techniques. In univariate regression, if a medium effect size is expected (i.e. Cohen's f2=0.15) then with a power of 80% and a 5% significance level a minimum of 54 participants would be required (Soper D.S. (2015). A-priori Sample Size Calculator for Multiple Regression [Software]). Anticipating a dropout of up to 10% we aim to recruit at least 60 participants.

Depending on data distribution, baseline comparison of QST data between LBP patients and healthy controls will be performed using parametric or non-parametric tests.

Univariate regression analyses will be performed to better understand the associations between the QST measures and the outcome variables.
Multiple regression analysis will be used to assess which variables best predict the extent of recovery from LBP. The dependent variable will be the extent of recovery measured using the 11-point Global Back Recovery Scale. Independent variables that will be entered into the regression model include sensory, psychological and clinical factors.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 290415 0
Name [1] 290415 0
Centre for Physical Health, Macquarie University
Address [1] 290415 0
Discipline of Physiotherapy, Ground Floor, 75 Talavera Road Macquarie Park NSW 2109
Country [1] 290415 0
Primary sponsor type
Dr Julia Hush
Ground Floor 75 Talavera Road, Macquarie University
Macquarie Park, NSW 2109
Secondary sponsor category [1] 289131 0
Name [1] 289131 0
Address [1] 289131 0
Country [1] 289131 0

Ethics approval
Ethics application status
Ethics committee name [1] 292039 0
Macquarie University Human Research Ethics Committee (HREC, Medical Sciences)
Ethics committee address [1] 292039 0
C5C Research Hub East
Level 3, Room 324
Macquarie University
NSW 2109
Ethics committee country [1] 292039 0
Date submitted for ethics approval [1] 292039 0
Approval date [1] 292039 0
Ethics approval number [1] 292039 0

Brief summary
Low back pain (LBP) is a highly prevalent health condition affecting up to 80% of individuals at some point in life. It is acknowledged that abnormal clinical findings, such as structural alterations of the spine found from imaging, poorly correlate with clinical status. Further, current prediction models that take into account psychological, demographical and physical factors explain only a small proportion of the variance in clinical outcomes. In recent years, evidence has accumulated that abnormal somatosensory processing occurs in people with chronic LBP. Psychophysical studies have commonly found pain hypersensitivity to various sensory stimuli in people with chronic LBP compared with healthy controls, not only at the back, but also at non-painful remote sites (e.g. at the hand). These changes in pain sensitivity in areas remote from the low back implicate abnormal central mechanisms.
At present, it is not yet established to what extent these sensory alterations contribute to the generation and maintenance of LBP. Also, the temporal aspects of these changes are unknown. However, recent research has shown that somatosensory abnormalities can be detected early (i.e. within 4 weeks) after the onset of LBP. These include augmented spinal cord excitability as well as pressure pain hypersensitivity. Further, longitudinal studies in acute whiplash injury cohorts have shown that widespread pain hypersensitivity persisted only in subjects who did not recover at 6 months. Cold pain threshold was found the sensory parameter that most significantly predicted non-recovery at 6 months. The primary aim of this study is to investigate whether psychophysical measures of pain sensitivity contribute to predicting non-recovery in low back pain and to evaluate the time course of somatosensory changes from the onset of low back pain to 4 months.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 53182 0
Dr Julia Hush
Address 53182 0
Ground Floor 75 Talavera Road, Macquarie University
Macquarie Park, NSW 2109
Country 53182 0
Phone 53182 0
Fax 53182 0
Email 53182 0
Contact person for public queries
Name 53183 0
Dr Julia Hush
Address 53183 0
Ground Floor 75 Talavera Road, Macquarie University
Macquarie Park, NSW 2109
Country 53183 0
Phone 53183 0
Fax 53183 0
Email 53183 0
Contact person for scientific queries
Name 53184 0
Dr Julia Hush
Address 53184 0
Ground Floor 75 Talavera Road, Macquarie University
Macquarie Park, NSW 2109
Country 53184 0
Phone 53184 0
Fax 53184 0
Email 53184 0

No information has been provided regarding IPD availability
Summary results
No Results