Psychological assessment for implantable therapies

Dr Pete Murphy

Consultant Clinical Psychologist

Dept. of Pain Management Walton Centre

Is psychological assessment necessary for SCS patients?

• YES - 1998 Consensus statement Task Force of the European Federation of IASP Chapters (EFIC) - Gybels et al. (1998)

• YES – 2004 Pain Society Guidelines

“data from the literature shows that a careful psychological screening leads to a significantly better outcome for SCS procedures”

Psychological Assessment of Candidates for Spinal Cord Stimulation for Chronic Pain Management.

Expert Panel Report 2004 (Beltrutti … North, Turk, Melzack & others)

Pain Practice vol. 4 Sept. 2004)Found• Personality per se is not predictive of outcome

• evidence supports psychological assessment, but it’s based on single centre studies, with different methodologies and small numbers therefore meta-analyses difficult

• recommend a brief battery with clinical interview

Why Assess ?Mental health problems common in

Chronic Pain

• Chronic Pain and anxiety 15% to 50% (McCracken et al. 1999)

• Chronic Pain & depression 30% to 100% (Fishbain et al. 1997)

• Chronic Pain and somatoform disorder ?(Bankier et al. 2000)

Psychological factors are associated with poor outcome

• Depression

• Catastrophising

• Anxiety

are strongest predictors of disability at 2 yr follow-up

Significantly better than pain or current level of disability (Sullivan 2001)

psychological factors contd...

• active psychosis• somatisation disorder• severe sleep disturbances• serious drug or alcohol addiction• lack of social support• major cognitive deficits• unresolved compensation• unrealistic outcome expectations(Gureje et al. 1998; Macfarlane et al. 1999)

Current UK practice Survey by ACKROYD et al. 2003

• 69 Consultants involved in SCS implants contacted -

44 responded

• 41 respondents work in MDT setting

• 38 had a Clinical Psychologist in the team

• 24 worked with developed guidelines

MDT Assess Psychologist Physiotherapist Consultant pain nurse

SCS Trial

PMP Individual therapy Psychologist Physio, OT, Medic

Permanent SCS Trial

Permanent Permanent

SCS Trial

Some PMP post implant

So for the MDT…

• The question is not just are they suitable but also are they ready?

Psychologist can be involved at:

Assessment & preparation

During the procedure (trial & implant)

Post trial

Post implant

Initial clinical interview

Psychosocial setting (maintaining factors)Family background, current stressorsSignificant others

• BeliefsCheck for understanding & possible misunderstandings

• ExpectationsDo they have a plan B if SCS doesn’t work?

State vs. Trait factors

Potential for clinicians to: overstate dispositional factors (neuroticism)

and underplay situational factors

Watch for psychopathologising a miserable situation

Poor outcome could be reflection of poor management – not the patient’s fault !

Facilitate patient risk assessment

• Anxious people may lousy statisticians

Do they understand the odds?

How is the information framed ?

• Get them to contemplate their own possible response to various outcomes

black & white or graded ?

Informed consent

• Agreeing or compliance?

demand characteristics/ social desirability

(May account for discrepancy between trial and permanent)

• Dissenting for the right reasons?

• How much do they understand?

Manage distress

• Work on their distress related or unrelated to pain, which if left untreated could interfere with SCS outcome

• Look for strengths in the patient as well as riskbut watch out for Excessive stoicism

Facilitate behavioural change

Breaking the habits of disability

• Goal setting and pacing

• Get them to internalise self-management rather than simply be compliant/ adherent

W ork

E motional

Travel

F unctional Tolerence

Relaxation

S leep

Leisure

C osmetic

Goal Them es

W ork

E motional

Travel

F unctional Tolerence

Relaxation

S leep

Leisure

C osmetic

Goal Them es

No Psychologist ?Psychometric screening & yellow flags

• reports pain being constant, no variability despite a range of interventions ‘nothing eases it’

• frequent visits to GP for pain or other issues >12 per year)

• Multiple complaints

Psychometric questionnaires

• Beck Depression Inventory-II

• Pain Anxiety Symptoms Scale

• Pain Catastrophising Scale

• Pain Self-Efficacy Questionnaire

• Roland & Morris Disability Questionnaire

• Visual Analogue Scale (pain)

What to look for in the questionnaires

Depression (BDI) – has 2 factors

1. Somatic factor - only high on this suggests primarily pain presentation

2. Cognitive-affective factor - high suggests depression

• If BDI >24 then possibly refer on

• If BDI >30 then always refer on

Catastrophising

• Pain Catrastrophising Scale (Sullivan 2001)

Highly associated with ongoing and future disability

Range 0-52

If >35 then possible refer on

Pain Self Efficacy Questionnaire

Assesses the patient’s view of their ability to manage their pain

Range 0 –60 (Higher better)

If <20 then possible refer on to psychologist

Pain Anxiety Symptom Scale

• assesses Fear Avoidance behaviour

• High score can be associated with poor adherence to exercise/rehab in long term

• Range 0-200

• If score >100 consider referring on

Refer to a clinical psychologist and/or PMP ?

• BDI (Depression) >24

• Catastrophising >35

• Pain Anxiety >100

• Self-efficacy < 20

If 2 out of 4 then definite yes

Case example 1

• Pt extremely fearful of procedures, fears paralysis

• History of an operation (yrs earlier) going wrong

• Daughter his source of anxiety & guilt

Involve family & educate

Case example 2

• Pt excellent trial response

• But high anxiety about op for permanent

Turned out source of anxiety was:

social and economic factors, child care & loss of income

and

‘playing her last card’

Case example 3

Significant Psychiatric co-morbid presentation

• Don’t proceed to trial

• Liaise with psychiatric services review following CBT intervention

Breakdown of all MDT Recommendations

23%

3%

6%

3%65%

Pre-trial PMPPost-trial PMPCBTOtherNo additional input

Result of SCS Trial: MDT vs No MDT(success => 50% pain relief)

71

29

62

38

0

10

20

30

40

50

60

70

80

%

MDA NO MDA

SuccessFailure

Permanent implants - 6 month follow-up

• 90% reported ≥ 50% pain relief for both MDA and No-MDA pts

• MDA greatest impact on trial selection

• and allowing more complex patients who may previously have been declined, to be considered for SCS

• Some non-MDA patients have required PMP etc later (observed trend)