Disability and coping are two of the most important targets in persistent pain management, along with distress and pain intensity (the latter perhaps being the most difficult to influence). A question, however, is whether existing measures of disability truly capture the activities or occupations that people most value. For example, if house cleaning is just not my thing, even if my functioning improved over the course of a programme, would I choose to spend that new capability on vacuum-cleaning or out there in the garden?!
The Westhaven-Yale Multidimensional Pain Inventory (MPI)(Kerns, Turk & Rudy, 1985) is a true workhorse of pain management measurement: It’s a measure that provides, via the subscales, an estimate of the complex inter-relationships involved in pain-related disability and distress. Three profiles of coping approach have been derived from the MPI indicating “Adaptive Coping” – the person is likely to continue to improve and engage in living well if they carry on as they are; “Interpersonally Distressed” – the person is experiencing difficulties with relationships and is feeling unsupported by others around them; and “Dysfunctional” – the person is struggling with their pain, and both disability and distress can feel overwhelming.
But the disability components of the MPI don’t really indicate the kinds of activities that people might be passionate about – or those that are relevant to their lives. The items are about general activities people “typically” do – in a North American setting. I know they’ve been validated in many different populations but they still represent a general idea of activity and function rather than the unique and idiosyncratic occupations that people do.
(What's the difference? An occupation is the unique way I perform the important tasks of my day - the way I dash around the house while simultaneously cleaning my teeth, getting the dogs outside, making sure the curtains are opened and the appliances off just before I head out the door! We could call this "getting ready for work" but the way I do it, and the way you do it is probably very different!)
Why is that important? Well, because people value different occupations differently, and because values drive motivation, a broad measure of disability may not capture the true value of a pain management programme. And this is why the Canadian Occupational Performance Measure (COPM) (Law, Baptiste, McColl, Opzoomer, Polatajko & Pollock, 1990) is often used by occupational therapists to establish exactly what it is a person wants to be able to do. Goal Attainment Scaling is another option.
In this study by Persson, Eklund, Lexell & Rivano-Fischer (2017), the aims were to assess longterm changes in MPI profiles over the course of a year; to look at associations between “Adaptive Coper” profiles at follow-up and improvements in occupational performance; and to look at factors at baseline that might be used to predict changes over time. Participants were, as usual, attending a tertiary pain management centre at a University hospital. They took part in a 21 day programme (oh the luxury of time!), and were seen by a team working together (oh the luxury of a co-located team!) including a psychologist, physician, physiotherapist, occupational therapist and social worker (oh for interprofessional teamwork!). The measures taken at pre and post were the MPI, COPM, and background demographic details.
Now here’s where the analysis gets pretty technical: dropout rates and pre-treatment differences amongst the MPI profiles were analysed using Matt-Whitney U, Kruskal-Wallis, chi-squared and independent t-test. Cross-tabs were used to describe the distribution of the MPI profiles. McNemar’s test was used to assess changes over time on each of the four profiles, and ultimately the participants were grouped into four profiles: never AC (Adaptive coper); losing AC; gaining AC, and stable AC, and these groupings were used to analyse associations between changes in MPI profile and changes on COPM from baseline to follow-up. And this, folks, is why occupational therapists NEED to learn statistical analyses! Because they went on to use univariate and multivariate logistic regressions to see whether demographic factors would predict these profiles at follow-up, incorporating satisfaction and performance scores on COPM.
What did they find?
More participants started the programme with a profile of dsyfunctional or interpersonally distressed than adaptive coper – and at both discharge and follow-up the adaptive coping group increased to be the largest subgroup. 20% of the participants ended up in the “gaining AC” group, 11% the “stable AC” group, 6% formed the “losing AC” group, and 63% were never in the adaptive coping group at all. Not so terrific in terms of broad outcome measures, but pretty consistent with other programmes around the world.
On the more individualised outcome measure of the COPM, people in the never AC group showed least clinically relevant improvement, both the stable AC and gaining AC groups showed more improvement on occupational performance and satisfaction with performance than the never AC group, while the stable AC group improved more than the losing AC group in terms of occupational performance changes.
Long-term changes showed those who started as AC were more likely to stay that way over time, and baseline scores for occupational performance were significantly associated with being AC at follow-up – in other words, people who felt OK about what they could do in terms of occupation, tended to become more capable and less disabled over time as measured by the MPI. More importantly, those people who had higher baseline scores on occupational satisfaction were 1.3 times more likely to shift to the AC group over time. “Clinically relevant improvements on performance and satisfaction with performance at 1-year follow-up, in occupations prioritized by the participants, were associated with having an AC profile at follow-up.” (p. 6).
Confidence in doing important occupations breeds confidence in other parts of living with persistent pain.
What does this all mean anyway?
Well, importantly, people who shifted from one of the other profiles to adaptive coping over a year showed clinically relevant improvements in occupational performance and satisfaction with performance – the authors suggest these findings show improvements on and satisfaction with “doing and performing” important occupations. Not being classified into adaptive coping at any time was associated with least improvement in occupational performance and satisfaction. There is an association between “doing/performing” and “coping/adapting” that hasn’t really been studied. Perhaps starting with things people enjoy instead of beating them over the head with things they’ve never been interested in could improve pain management outcomes. Pain management programmes DO influence doing in real life – if real life doing is used as therapy!
The authors also point out that “30–47% of participants who did not show an AC profile at follow-up still showed clinically relevant improvements on occupational performance and on
satisfaction with occupational performance.” (p. 8) This suggests that the MPI coping profiles only represent one part of the outcomes that are important to individuals: occupation being the individualised daily doings that people value very highly, and pointing to the need to explore individualised outcome measurement in more studies. Given that patient-centred pain management is based on individual goals, using only generic measures is likely to give misleading outcomes about treatment efficacy.
Kerns IVRD,TurkDC, Rudy TE. (1985) West Haven-Yale Multidimensional Pain Inventory (WHYMPI). Pain. 23:345–56
Law M, Baptiste S, McColl M, Opzoomer A, Polatajko H, Pollock N. (1990). The Canadian Occupational Performance Measure: an outcome measure for occupational therapy. Canadian Journal of Occupational Therapy. 57(2), pp82–7.
Persson, E., Eklund, M., Lexell, J., & Rivano-Fischer, M. (2017). Psychosocial coping profiles after pain rehabilitation: Associations with occupational performance and patient characteristics. Disability and Rehabilitation: An International, Multidisciplinary Journal, 39(3), 251-260.