How Is Pain Measured?

[Iamme]

Another standard pain stimulus used is a bucket of ice water. Submerge your arm in it up beyond the elbow and keep it there as long as possible.

Never seemed that painful to me, but I have had students who could not go half a minute.

A test like this would not prove anything. All it would prove is how much of a "man", a person was. And I guess you really wouldn't know that either, since, for one person, if they really didn't get bothered by cold ice...and another person really would...you wouldn't know. I feel intense pain from cold rain water just hitting my skin. Seriously. I mean it really hurts. but nobody else would know this as I obviosly keep this to myself so I don't seem like a total woos.

 

[Iamme]

You ever see football players train? We had the Giants training on campus about ten years ago. They train by running into these big padded skids as hard as they can. The college players do it too. They get used to it. And there's the "take it like a man" thing.
"Oh, Boomer broke his collarbone. Shake it off Boomer."

I think you are onto something there. So you are saying that pain felt is relative to one's familiarity with it?

 

[Iamme]

Another standard pain stimulus used is a bucket of ice water. Submerge your arm in it up beyond the elbow and keep it there as long as possible.

Never seemed that painful to me, but I have had students who could not go half a minute.

Maybe the best one can do is ask each person how it feels. Not whether or not someone leaves their arm in there longer.

 

[Jeff Corey]

I think you are onto something there. So you are saying that pain felt is relative to one's familiarity with it?

More like the amount of pain endured is increased with training to endure it. Or experience with it.
I've seen kids fall down and get up and keep on running. Other kids fall down and a parent comes over and says "Omygawd! Are you OK? Let mommy see it. kiss it and make it better."
You can train people to be hypochondriacs. "Mumsy, I don't wanna go to school, I have a tummy ache." "Oh, Chesley, fer sure, stay home."
Pain is two things. What you feel and what you express to others. What you express to others can be radically modified by what it gets you.

 

[Iamme]

I had as next door neighbor friend when growing up who had to have his mother wash out every wound with mecurichrome, methialate, and all that stuff. And when he had a tooth pulled he scared the be-Jesus out of me with his tale of horror, because *I* had to go in and have 4 pulled out...at once! Do you know I asked the dentist when he was going to pull them, after I felt my head yanking back and forth?...and he said they were all out already? Either my friend was a total woos, or had a bad dentist.

 

[TobiasTheViking]

i'm currently at 4 on a 10 scale(logarithmic).

It is a migraine that has been building for about a week. it started at 2 last week, came and went a few times and slowly increased to 3. Today it is at 4.

Now, it hasn't be constant pain for the last week, coming and going, sometimes a day or two between the pain. But.. today i'm at 4.

*sigh*

time to pop pills.

 

[bpesta22]

One could use signal detection theory to separate the "macho; take it like a man tendancy" from actual sensitivity to pain (beta versus d prime).

It would be the individual or group differences in d' that would let you say one person/group is more sensitive to pain.

From Coren and Ward: Women are generally more sensitive to pain produced by electric shock, and women's pain thresholds also seem to vary over the menstrual cycle. These differences are not due simply to some macho denial of pain sensations on the part of men because subtle autonomic measures of pain responses that are not under voluntary control, such as the change in the diameter of the pupil of the eye, show less male sensitivity to painful stimulation.

 

[Jeff Corey]

That exemplifies the problem with nonexperimental research. How do we know whether these gender differences you cite are not due to differential treatment during infancy , childhood and young adulthood?

 

[This Guy]

More like the amount of pain endured is increased with training to endure it. Or experience with it.
I've seen kids fall down and get up and keep on running. Other kids fall down and a parent comes over and says "Omygawd! Are you OK? Let mommy see it. kiss it and make it better."
You can train people to be hypochondriacs. "Mumsy, I don't wanna go to school, I have a tummy ache." "Oh, Chesley, fer sure, stay home."
Pain is two things. What you feel and what you express to others. What you express to others can be radically modified by what it gets you.

How many times have you seen kids fall, or bump themselves, and show no sign of discomfort, until Mommy runs over in shock asking if Mommy's baby is OK, at which point the child starts bawling?

I think part of our perception of pain depends on our mindset (for lack of a better term). If I'm busy, and distracted, and bump my knee for example, I'll likely give an oww, and move on with what I'm doing, not noticing the pain much. But if I'm just messing around, say getting up from the table to get a book to read (or whatever mindless activity) and bump my knee, I may well spend more of my attention on the pain, and perceive the same amount of pain as being a lot worse. Yea, not a lot of science behind that statement, but hopefully it makes sense

On the other hand, I have my own pain scale. It's based on what I say when I get hurt. It goes roughly like this (from minor to major pain)-

1= Oww!
2= Dang!
3= Crap!
4= Damnit!
5= $hit!!
6= Son of a B****!!
7= God D*** it!!!
8= Mother F*****!!!
9= G** D*** Son of a Mother F****** B****!!!!!

You don't want to see what comes out for a 10!

I call it my Sailor's Scale of Pain (Pat. Pending;-)

 

[bpesta22]

That exemplifies the problem with nonexperimental research. How do we know whether these gender differences you cite are not due to differential treatment during infancy , childhood and young adulthood?

It's possible, but why would they then vary with the cycle?

Could differential treatment affect pupil size changes in responses to different magnitudes of electric shock?

 

[Jeff Corey]

It could through stimulus generalization as an aftereffect of pavlovian (respondent) conditioning.
"Does your dogga bite?"

 

[TruthSeeker]

A few comments:

The first thing we need to consider is the type of pain being assessed. What Pesta (Aside to Pesta: SDT really isn't appropriate for pain. See Rollman in the mid 1980s. Exact ref available when I get home) Mercutio and possibly others are describing is experimentally applied painful stimulation - usually (but not always) applied to healthy volunteers. Interesting stuff, but the question remains as to whether or not the results found are applicable to clinically relevant pain (In fact, I just accepted an invitation to write a paper on exactly this topic).

The biggest issue is that the experimental situation simply cannot parallel the clinical situation. Pain is a subjective multidimensional experience which is influenced by biological, cognitive, and emotional factors including things like a person's age, gender, previous experience, mood, fear of pain, and most important to this discussion, the meaning of the situation. There is no way that the pain I apply to a subject in a carefully controlled experiment where he/she knows they will not have any permanent damage and can terminate the stimulation at any time can parallel the pain felt by a cancer patient who is afraid that the pain will be unending and may signal disease progression etc. So, many of the experimental methods are not really clinically relevant.

Clinically, the most common pain measure is the numeric rating of 0-10 which has been endorsed for clinical trials and other types of studies and across the lifespan. Although it has some problems psychometrically, our understanding of its properties is continually growing. For instance, there is ongoing work into clinically meaningful differences etc. And, it is easier for more vulnerable people - like children and the elderly - to use than visual analog scales. Of course, it can't be used for people who cannot express their pain verbally. But many groups (mine included) are working to develop methods to assess pain in people who cannot communicate verbally.

Up to this point, we've only talked about the intensity of pain or how much it hurts. Also important are pain qualities, or how the pain feels. The most common measure of this is the McGill Pain Questionnaire which is a list of adjectives describing the sensory, affective and evaluative qualities of pain. So, this measure helps us to discriminate different types of pain: for instance, a tension headache, migraine and a neuropathy might all be rated 7/10 but the tension headache might feel "dull" and "heavy", the migraine "pounding" and the neuropathy "burning" "shocklike". Those words are really helpful with diagnosis and with understanding the effects of different treatments.

Finally, a good pain assessment includes a measure of pain's impact on physical, psychological and social function. Usually, this is measured by asking to what extent the pain intereferes with desired activity, mood etc.

As for comparing across different types of pain. Extremely difficult to do, but has been done with the MPQ. I once posted a chart here of the rankings of different types of pain. I'm not on my computer right now so can't find it at this moment. I'll try to search for it later.

Gender and pain: huge issue. The best answer to this one is that the differences are the final outcome of psychological, social, and biological differences between the sexes. Hormones definitely play a role (and Jeff Mogil has been showing that female rats may have a unique endogenous pain inhibitory system). However, in humans, boys and girls are taught different things about the acceptability of expressing pain, and we know that men and women employ slightly different coping styles and are responded to differently by the medical system. So, the gender differences are multidetermined. None of the gender and pain researchers I work with think there is a unifactorial explanation.

 

[Luciana]

Contact Truthseeker, she's a researcher in that area. Or, rather, run a search for the word "pain" by user Truthseeker in the Search feature. I remember once she posted a diagram with pain levels, and that might answer your question. Just PM her, this is a subject she dedicates her life to and she loves it.

 

[Luciana]

OMG Truthseeker!!!!! You're here!



geez, thank Ed I'm a skeptic, or I'd be freaked out with the coincidence.

 

[TruthSeeker]

OMG Truthseeker!!!!! You're here!



geez, thank Ed I'm a skeptic, or I'd be freaked out with the coincidence.

I think your thoughts were transmitted by your spiritual guide to mine. My spiritual guide then led me to this thread. There can be no other explanation.

 

[bpesta22]

TS

Thanks!

I would be interested in the SDT not being good for pain citation if it's not too much trouble.

Is any of the classic psychophysics stuff relevant to what you do?

I was trying to work out in my mind how SDT might be used to separate pain sensitivity from willingness to report that it hurts.

 

[bpesta22]

TS.

I wonder if you could do a factor analysis on all the pain survey items and see if there's a general factor for pain, or how many factors are needed (and what they are) to explain the variance.

I'm guessing someone's done something like it.

 

[Mercutio]

I was trying to work out in my mind how SDT might be used to separate pain sensitivity from willingness to report that it hurts.

Heh...wouldn't you need multiple trials, to distinguish bias from sensitivity? Rather difficult to do with real-world pain, as opposed to experimental.

Thanks for the info, TS! I guess my own bias as an experimentalist is showing!

 

[bpesta22]

Sorry about the multiple posts here-- TS, found the cite re google (thanks).

Merc, yes I reckon it would. We would need to find some undergrads willing to take one for the team.

 

[TruthSeeker]

TS

Thanks!

I would be interested in the SDT not being good for pain citation if it's not too much trouble.

Is any of the classic psychophysics stuff relevant to what you do?

I was trying to work out in my mind how SDT might be used to separate pain sensitivity from willingness to report that it hurts.

Gary Rollman is the author...If I forget to send it, just remind me.

My work is with cancer patients, so psychophysics isn't really relevant. We do quantitative sensory testing to measure changes in sensitivity throughout treatment. But that is different.

TS.

I wonder if you could do a factor analysis on all the pain survey items and see if there's a general factor for pain, or how many factors are needed (and what they are) to explain the variance.

I'm guessing someone's done something like it.

For intensity measures - one factor. For qualitative measures - 3 -4 factors (sensory, affective, evaluative and a sort of miscellaneous cluster)

Heh...wouldn't you need multiple trials, to distinguish bias from sensitivity? Rather difficult to do with real-world pain, as opposed to experimental.

Thanks for the info, TS! I guess my own bias as an experimentalist is showing!

I don't remember Rollman's criticisms (haven't read the paper since grad school) but yeah, can't do SDT with clinical pain.

You are very welcome, Merc. And, it's good for clinical types like me to talk with experimentalist types like you. Too easy to lose track of each other.