physiotherapy research society may 2012 stephen may, sheffield hallam university

The evolution of research into management of low back

pain

Physiotherapy Research SocietyMay 2012

Stephen May, Sheffield Hallam University

Low back pain is extremely common

60-80% of adults at some point in their lifetime

The most costly single health problem for which an economic analysis was available (Maniadakis & Gray 2000)

Background

15% CLBP account for about 70% of costs (Linton et al 1998)

But what is the optimal management?

Despite billions of $ / £ invested in research over the last few decades do not seem to be any nearer an answer

Background

Where research has come from?

What concepts have influenced clinical practice and the research agenda

Highlight some of the limitations / problems with these approaches

Structure of session

Think about some new directions that LBP research is going in

That hopefully my produce more positive findings

And influence clinical practice

Structure of session

Patho-anatomical disorder within a biomedical model

Facet joint, disc pain, instability, SIJ etc

But actually ability to identify these so-called pathologies from clinical examination is very limited (Hancock et al 2007)

The past

Disc

Facet

SIJ

Diagnosis disc / facet / SIJ

Centralisation◦ Spec – 0.7-0.9◦ Sens – 0.2-0.92

Not informative

>3 PPPP◦ Spec – 0.7-0.8◦ Sens – 0.7-0.89

4 articles with 11 clinical tests

Majority of tests demonstrated limited ability to make diagnosis (sensitivity)

Diagnosis of lumbar segmental instability (Alqarni et al 2011)

‘Common patho-anatomical findings such as degenerative disc disease, annular tears, fissures, facet joint arthrosis and disc bulges have been found to be not predictive of future LBP.’

‘Diagnostic labels such as ‘instability’ should be reserved solely for ‘unstable fractures’ and ‘unstable spondylolisthesis.’ (O’Sullivan 2012)

It’s time for a change with management of NSLBP

Identification can be done with radiographically controlled injections

But has not actually led to improved treatment outcomes

These are not commonly available

The past

Furthermore only 8-15% can be given a specific diagnosis

So > 85% labelled non-specific LBP

Research has focussed on NSLBP with little attempt to identify specific groups

The past

Non-specific LBP has been randomly allocated to 2 or more treatment arms

Mean difference between treatment arms calculated

Does not provide information on individual responses, only averages

Who will respond best?

Research in the past

Pragmatic multicentre RCT LBP < 12 weeks duration

402 / 544 recruited and 329 followed up at 12 months

Randomised to: 1. pain management (advice, coping strategies,

usual activities, general exercises) 2. physiotherapy package (manual therapy,

stabilisation exercises, advice)

Example – Hay et al (2005)

Hay et al (2005) Primary outcome =

RMDQ at 3 & 12 months

Change scores = mean (+/- SD)

No significant difference between groups

3/12 (1)

3 /12 (2)

12 / 12 (1)

12 /12 (2)

02468

1012141618

Hay et al (2005) Pain management (1) v

physiotherapy (2)

Self report at 12 / 12: A. Completely better B. Much better C. Better D. Same E. Worse F. Much worse Tx 1 Tx 2

0

10

20

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ABCDEF

So overall no significant difference and no difference in self-reported outcomes

But SD displayed huge range of responses, bigger than the mean differences over time

Some patients had major changes on RMDQ (14-15) and others had minimal (<3)

But cannot tell who responded best to each Tx

Hay et al (2005)

RCT SR Guidelines

Now numerous guidelines exist

Guidelines based on randomly selected patients, rather than selected on appropriateness of Tx

Past recommendations

Review of17 guidelines for LBP (van Tulder et al 2004; Arnau et al 2006)

Classification and therapeutic recommendations were largely similar

But ‘quality of reporting of guidelines was disappointing’ against the AGREE tool for appraisal of guidelines

Past recommendations

Assessment: To exclude serious spinal pathology For prognostic factors (yellow flags)

No treatment has been shown to be consistently superior

Exercise, manipulation, and CBT-type of approaches

(Airaksinen et al 2006)

Past recommendations - CLBP

TENS, hot/cold, traction, laser, US, SWD, IF, massage, corsets, and acupuncture CANNOT be recommended

Airaksinen et al 2006

Past recommendations

NICE guidelines suggest course of exercise, manipulation, acupuncture (8-10 sessions of each!)

If one fails try the next, and so on

If all fails then try 100 hours of CBT!

Past recommendations

Guidelines often arbitrary division into acute / chronic LBP

Acute LBP EG had 4 major recommendations◦ Reassure patients◦ Do not prescribe bed rest◦ Advise patients to stay active◦ Regular pain relief

? Manipulation No specific exercise

Van Tulder et al (2006)

Past recommendations

But guidelines present one-size-fits-all generic management advice

Just like the past RCTs does not tell you what you need to do with the patient in front of you

Past recommendations

‘Greatest danger of flawed clinical guidelines is to patients’:

‘Suboptimal, ineffective or harmful practices’

What is best for patients overall....... May be inappropriate for individuals.’

‘May come at the expense of reducing individualised care for patients.’

(Woolf et al 1999, BMJ)

Guidelines – potential harms

Clinicians do not belief that NSLBP is an homogeneous group (Kent & Keating 2004)

In other words sub-groups may require different interventions

Sub-groups based on clinical presentations

Are we missing something?

Better attempt to sub-classify patients prior to treatment

Treatment according to classification

Growing evidence of the relevance of this approach

The future for better back care?

Treatment-based classification (Delitto, Fritz et al)

Directional preference / centralization (McKenzie, Long, Werneke et al)

STarT back screening tool (Hill, Main, Hay et al)

Examples of different approaches to basing Tx on sub-classifications

Benefits of sub-grouping

• 76 patients acute LBP randomised to AHCPR guidelines OR treatment by classification

(Fritz et al 2003)

• Oswestry scores0

5

10

15

20

25

30

35

40

45

50

0

4w*

52w

AHCPR

sub-group

Benefits of sub-grouping

• 76 patients acute LBP randomised to AHCPR guidelines OR treatment by classification

(Fritz et al 2003)

• Oswestry scores0

5

10

15

20

25

30

35

40

45

50

0

4w

*

52w

AHCPR

sub-group

Benefits of sub-grouping

• Brennan et al (2006) recruited 123 sub-acute LBP and analysed outcomes in 3 ways:

• Randomised: manip / stab ex / dir pref

• Sub-group – identified after & blind to randomisation by pre-established rules

• If sub-group matched / unmatched by randomisation

Acute LBP

Baseline evaluation

R

Manipulation Stabilisation Dir Pref Ex

M UnM M UnM M UnM

CPR criteria

Benefits of sub-grouping

• Outcomes = Oswestry 4w and 52w

• Randomised groups P = 0.37

• Classified groups P = 0.19

• Matched / unmatched P = 0.013

Clinical features sub-classification systems CPR

Clinical features associated with improvement if treated with SMT (Flynn et al. 2002, Childs et al. 2004, Fritz et al 2004, 2005, Brennan et al. 2006, Cleland et al. 2006)

Clinical features associated with improvement if treated with SE (Hicks et al. 2005, Brennan et al. 2006, Teyhen et al. 2007)

Cohort all treated

Good responders defined as at least 50% improvement on Oswestry

Characteristics of those who so improved

Then RCT

Clinical prediction rules

Clinical prediction rules SMT

Duration of symptoms < 16 days

One hip with > 35ᵒ MR Lumbar hypomobility No symptoms distal to

knee FABQ work score <19

SE

+tive prone instability test

Aberrant motion (painful arc, Gower sign, catch, reversal of rhythm)

SLR >90ᵒ Age <40 years

Following on from derivation these need several stages of validation

SE CPR has not been validated

SMT CPR has been validated in one study but not in another population

Clinical prediction rules

Directional preference

312 patients – mechanical evaluation (Long et al 2004)

230 (74%) DP◦ Ext 191 (83%), flex 16 (7%), lateral 23 (10%)

Randomised to matched or opposite exercise or EBM guideline group (nearly 70 each group)

Benefits of sub-grouping

• 312 patients assessed – 230 (74%) with DP

• 230 randomised to matched / opposite / non-specific guideline approach

• RMDQ

(Long et al 2004) 0

2

4

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14

16

18

20

0 2w*

match

opp

control

Self-rated improvement at 2 weeks (Long et al 2004)

0

10

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30

40

50

60

match opposite control

resolved

better

no change

worse

Secondary analysis - Long et al 2008

At 2 weeks those who were 'worse' 'unchanged' or wanted a different exercise were offered cross-over T

96 initially unmatched patients then got matched DP

Long et al 2008

2

2.5

3

3.5

4

4.5

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5.5

6

6.5

baseline 2 weeks* 4 weeks*

Opposite Non-directional

0.5

1

1.5

2

2.5

3

3.5

4

Baseline 2 weeks 4 weeks*

Opposite Non-directional

Back Pain Leg Pain

Directional preference In those with DP – DP exercises significantly

better outcomes than other exercises

In initial trial and when swopped over from non-specific to DP exercises

74% of assessed patients had DP◦ Acute to chronic◦ LBP with / without leg pain

STarT Back - classification by risk Hill et al (2008, 2009, 2010, 2011)

developed and validated a 9-question tool for determining those at prognostic risk◦ leg pain◦ comorbid pain◦ disability (items)◦ bothersomeness◦ catastrophising ◦ fear ◦ anxiety◦ depression (psychosocial subscale)

STarT Back 0-3 = low risk Advice session

4 or 5 on psychosocial subscale = high riskpsychologically informed

physiotherapy

rest = medium risk Standardised physiotherapy

STarT Back RCT 851 patients randomly assigned to risk-

informed Tx or control

Control = initial advice session, with option referral for further physiotherapy

469 assessed at 12 months (76%), but ITT analysis used

STarT Back RCT 26% / 46% / 28% were low / medium / high

risk

In control group >1/3rd medium and high risk not referred; half of low risk were referred

Mean number of Tx sessions same

Changes in RMDQ: All / Low risk

p=0.0001 / 0.0095 p=0.22 / 0.846

base-line

4m 8m 12m0

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base-line

4m 8m 12m0

0.51

1.52

2.53

3.54

4.55

12

Changes in RMDQ: Medium / High

p=0.0012 / 0.0253 p=0.0024 / 0.1547

base-line

4m 8m 12m0

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base-line

4m 8m 12m0

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Baseline scores

function, LBP, catastrophing leg pain, below knee

RMDQ

pain pcs0

5

10

15

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25

30

lowmediumhigh

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80

low mediumhigh

Appears to be a useful tool to help identify patients with risk of prognosis

Relates to previously known prognostic factors

Can help to direct scarce resources to those most in need of more involved interventions

STarT Back

In the past non-specific LBP led to failure to select

Patients randomised to Tx regardless of whether appropriate

Mean differences hid responders / non-responders

Some Tx appeared superior

Conclusions

But overall differences between groups were minimal

Is there a way forward to improve outcomes?

Sub-classification based on clinical presentations

Conclusions

TBC - DP, SMT, SE - based on clinical factors

DP / centralisation - based on repeated movements

Prognostic risk factors - based on questionnaire

Conclusions

All have shown significant and improved outcomes in different study designs

But still using RCT-methodology, which is the only way to determine Tx superiority

Conclusions