measuring pain: not a trivial task (2017)

Measuring pain: not a trivial taskPeter KamermanUNIVERSITY OF THE WITWATERSRAND

www.painblogr.org @painblogR

Johannesburg Pain Academy, 25 February 2017

www.painsa.org.za @painsouthafrica #JHBPainAcademy2017

• Information gathering

• Decision making

Why do we measure pain?


Domains of pain

Pain

Sensory

AffectiveCognitive


What do you want to know: Unidimensional

What do you want to know?

Intensity

RiskQuality

InterferenceVisual analogue

scale (VAS)

Numeric rating scales (NRS)

Faces Pain Scales (FPS)Actigraphy

Verbal rating scales (VRS)

Tampa Scale of Kinesiophobia

(TSK)

Brief Pain Inventory: Interference Scale (BPI-I)

McGill Pain Questionnaire (MPQ)

Neuropathic Pain Symptom Inventory (NPS)

Tampa Scale of Kinesiophobia (TSK)

Pain CatastrophizingScale (PCS)

Coping StrategiesQuestionnaire (CSQ)


What do you want to know: Multidimensional

What do you want to

know?

Intensity

Risk

Quality

Interfer-ence

Brief Pain Inventory (BPI)

Universal Pain Scale

Multidimensional Pain Inventory (MPI)

McGill Pain Questionnaire

(MPQ)

Neuropathic Pain Symptom

Inventory (NPS)


Whatever you use, know your instrument

PainScale

Validity

Reliability

Utility

Scale


Validity

Validity cannot be assumed

• Face validity, construct validity

• Pain type

• Age

• Educational level / mental status

• Culture


Validity

Yasbek M, Stewart A, Becker P

Conclusion: From the statistical analysis of the results, it became apparent that the subjects tested did not have an understanding of any of the three pain scales.


Validity

In conclusion, we show significant similarity in the terms used to describe neuropathic pain in isiZulu compared to non-African languages, thus indicating that translation of existing neuropathic pain screening tools into this, and possibly other Bantu languages, is a viable option. However, the usefulness of English-language screening tools in this non-native English speaking population may be limited.


Validity

“…men are not allowed to show their pain (physical or emotional). Expressing pain in any manner is strictly taboo as it is indicative of being weak. [Women] on the other hand, should express her level of discomfort in any way possible as it will ensure she receives help”.

“…when you have pain there is high possibility that you are being bewitched…”


Utility

Clinical vs Research

Focussed vs General


Linearity and ratio-scaling

• Are the distances between points on the

scale equal?

• Does the scale have a true zero?


He said, she said…

Subjective vs Objective

measures


Physical activity: an objective measurement?



Dysmenorrhoea

No dysmenorrhoea

Menstruation

Least pain Intermediate pain

Worst painLatefollicular

Phys

ical

act

ivity

(%)

5

10

25

15

20

0

Chantler et al. J Pain 10: 38-46, 2009a



Menstruation

Placebo DiclofenacLatefollicular

Tim

e to

com

plet

e ta

sk (s

)

70

60

50

80

Chantler et al. J Pain 10: 191-200, 2009b



Chantler et al. J Pain 10: 191-200, 2009bMenstruation

Placebo DiclofenacLatefollicular

Hea

rt ra

te(b

eats

/min

)

180

160

200

140

Dur

atio

n of

Ex

erci

se (m

in)

8

6

10

4

12



Wadley et al., PeerJ 4: e2464, DOI 10.7717/peerj.2464, 2016

Employed Unemployed

No chronic pain Chronic pain No chronic pain Chronic pain

0

100

200

300

Tim

e sp

ent a

ctive

per

day

(min

utes

)


• Choose your assessment method according to your requirements.

• Be aware of the limitations of your assessment method.

Summary

TL;DR

“Science that jumps to measurement too soon is as unsound as science that ignore measurement too long.”

John Rodgers(US Naval Officer)

measuring pain: not a trivial task (2017)

Health & Medicine