PHODA findings - chronic low back pain and people with high and low kinesiophobia
Posted Jan 22 2009 5:14pm
I’ve written quite a few times about the PHODA - photographs of activities of daily living - and I’m in the process of developing a New Zealand contextual version of it for use in the Pain Management Centre in which I work. Today I’m briefly discussing another paper in press about the use of a modified PHODA in people with low and high kinesiophobia (fear of movement with subsequent avoidance behaviour). Many of the papers on the PHODA are from Maastricht University, so it’s nice to see a paper written by researchers in Ohio, USA conducting this piece of research - the more this model of ongoing disability associated with pain is tested in different populations, the more the model can be said to be representative.
Trost, France and Thomas have previously demonstrated that people with chronic low back pain with high kinesiophobia predict higher pain, experience greater pain and are more fearful of harm while undertaking graded reaching tasks than those with lower kinesiophobia (Trost, France & Thomas, 2007). This new study was developed to examine the relationship between PHODA responses to pain and harm concerns reported during the standardised reaching movements previously reported.
Just as an aside, pain-related fear and avoidance is only one pathway through which people experience ongoing disability associated with pain. What is promising about this model is that already established treatment approaches used in other phobia’s have been successfully translated to treat it. What isn’t certain yet is how quickly kinesiophobia occurs after pain onset, and whether it can be prevented with good information and expectations about recovery as part of public health and primary care strategies. It is generally accepted that high levels of pain-related fear are likely to predict future episodes of disability associated with pain, which is particularly important in the case of low back pain which often recurs.
Participants in this study were recruited from the local community, and had low back pain for around 7 years. Only 33 participants took part in the study, limiting its generalisability considerably, and they differed from those referred to our service in that they were younger (these people were 32.1 years SD=10 years). The authors of the study don’t describe any other features of their pain and function apart from using the following scales:
Tampa Scale for Kinesiophobia (17 item version), rated on a four-point scale anchored ’strongly disagree’ to ’strongly agree’. This scale has a two-factor structure of somatic focus (believing that pain is a sign of serious pathology or underlying damage), and activity avoidance (believing that activity will either increase pain or produce more damage).
Visual analogue scales were used for predicted and experienced pain and harm. Each scale was a 10 cm horizontal line with no numbers, marks, or descriptive vocabulary with anchors at each end of ‘no pain’ and ‘worst imaginable pain’ (for the pain VAS), and ‘not at all concerned’ to ‘extremely concerned’ for the harm VAS.
The PHODA - modified version was used. This was a 20-item set of photographs (instead of the 100 originals). They were administered in the same way as the original PHODA, with two vertical rating scales, one of harm and one of pain. Each scale was numbered 0 - 100, with ‘not at all painful’ to ‘worst possible pain’ on one, and ‘not at all concerned’ and ‘extremely concerned’ on the other.
The Roland Morris Disability Questionnaire was also used to establish functional/disability status. This measure has 24 items scored yes or no to functional activities the person may encounter and limit as a result of their back pain.
The Short form McGill Pain Questionnaire was used to indicate the quality of pain the participants had prior to the commencement of the measures. This consists of 15 words that are drawn from the original McGill Pain Questionnaire, ranked on a four point scale of 0 (none) to 3 (severe). The SF McGill also has a 10cm VAS and a present pain intensity rating of 0 - 5.
There were four groups of movement the participants were asked to complete. These are well-illustrated in the paper, so I won’t review them here. They do involve various positions of back flexion, adjusted for the individual, and various speeds of movement and load weight. The tasks were completed after participants completed the questionnaire battery identified above with the exception of the PHODA. The PHODA was administered after the task, and again instructions as to how this was presented are well-described in the paper.
Cutting to the chase - what did they find?
The mean score for participants was 40.8 (SD=8.2), with the mean score on the Pain Rating Index 13.7 (SD=9.2). Disability as measured on the RMDQ was 8.9 (SD=6.4). The group were divided into high or low kinesiophobia based on the TSK median score (42), with 14 participants identified as ‘high kinesiophobia’ and 19 as ‘low kinesiophobia’. No differences between the two groups in terms of age, duration of pain, but pain intensity and disability were markedly different with kinesiophobic participants scoring much more highly.
People with high kinesiophobia both predicted and experienced greater pain intensities during the tasks than people with low kinesiophobia scores. The same finding was obtained with regard to harm ratings. This same relationship didn’t hold for people identified with low kinesiophobia ratings.
This suggests that in people with high kinesiophobia, part of the problem is their anticipation and prediction of harm and pain before they do activities that bother them - and then as a result, they experience greater pain which serves to confirm their fears. This doesn’t appear to be as strong a link in people with lower levels of kinesiophobia.
Some interesting conclusions, although the study size is still quite small. Something I found particularly interesting is that they conclude that clinic-based assessments and exposure sessions do appear to have ‘ecological validity’. What this means is that what occurs in the clinic seems to translate to limitations in the real world. I’m not sure that I totally agree with their conclusion that if a person can confront a fear in a clinic they will go on to confront it in real life. I rather think that people may limit themselves in a clinic and in real life (as measured both by functional tasks and disability questionnaires), they may participate in exposure in the clinic - but then fail to show improvement in disability in the real world. So for me, the movement may go one way only. I also think there is a difference between reviewing photographs in a clinic and performance in a clinic, versus reviewing photographs in a clinic and actual performance in the real world. It is something to look at further.
The authors do note that there are limitations to their study, particularly that the tasks used were not selected by the individuals and may not have challenged them enough, nor perhaps represent the most relevant activities for the individuals. They also note that the PHODA was rated after the task, which in itself is an exposure session - it would be interesting to look at PHODA scores prior to the activity. They note the photographs used in this study don’t represent the clinical tools available, and they altered the procedure for administering the PHODA. And finally, they do acknowledge that self-report tools of any kind may have quite limited predictive validity within the real world - so it would be interesting to look at this in an ecologically valid situation, perhaps using AMPS or similar in the person’s own home environment, or perhaps work environment.
Z TROST, C FRANCE, J THOMAS (2009). Examination of the photograph series of daily activities (PHODA) scale in chronic low back pain patients with high and low kinesiophobia Pain DOI: 10.1016/j.pain.2008.11.016
Trost Z, France CR, Thomas JS. Exposure to movement in chronic back pain: evidence of successful generalization across a reaching task. Pain 2007