The reliability of determining “leg dominant pain”

Validity of a single-item measure to assess leg or back pain as the predominant symptom in patients with degenerative disorders of the lumbar spine

“…This may have indicated that in the self-administered versions the clarity of the wording was not optimal and that problems of comprehension may have led to the poor reliability for some instruments. This is also suggested by the finding that their self-administered instrument suffered from a higher proportion of missing data, with up to 25 % patients failing to answer an item or providing an inappropriate response on either the test or retest [1]. In the present study, only one patient out of 45 in the reliability study failed to complete the leg pain scale (and did so on both test and retest, such that we presume the patient simply had no leg pain at all and hence chose not to mark anything), and in one patient the pain scales were not completed pre-operatively (it appeared that the patient had overlooked the whole page containing these items in the questionnaire booklet).…”

“…Wai et al [1] used 8 self-administered instruments to assess the predominant pain location and, depending on the instrument used, found that up to 32 % patients provided a completely opposite response on retest compared with their initial response. When the same instruments were administered by an interviewer, the figure was \10 %.…”

“…as back pain, leg/buttock (sciatic) pain, neurological disturbances] were easier to understand, leading to less missing data and good reliability. In the study of Wai et al [1], cross-validation between different instruments purporting to measure the same phenomenon (dominant pain location) revealed weighted j values of 0.27-0.65. When the results of all the psychometric quality tests were considered together, their ''percent back, percent leg pain'' item appeared to perform best of all, followed by their Numeric Rating Scale (NRS), and a question on the region as to which the patient would assign priority for treatment.…”

“…It has been suggested that, since surgical treatment is only appropriate when the specific pain generator is known [1], determination of the aetiology of the pain is required to dictate both the need (or otherwise) for surgery [2] and the primary surgical procedure to be applied [1]. It has been a long-held belief in clinical practice that leg pain dominant over back pain is an important factor in determining the degree of surgical success, especially in relation to decompression surgery [1,3,4]. However, until recently, this empirical belief had not been formally tested in studies that had actually quantified relative leg pain and back pain intensities.…”

“…Its role in predicting the outcome of degenerative spondylolisthesis remains controversial, with some authors reporting a significant relationship [7] and others failing to observe any significant effect [8]. However, the validity of these findings is threatened somewhat by studies that challenge the reliability and validity of methods used for determining ''leg-dominant pain'' [1]. Cross-validation between different instruments purporting to measure the same phenomenon (i.e., dominant pain location) revealed weighted j values of 0.27-0.65, depending on the instruments compared.…”