Worth W. Everett

Spiritual healing as a therapy of chronic pain

We read with great interest the randomized clinical trial by Abbot et al. (2001) that sought to assess the efficacy of spiritual healing in chronic pain. Measuring and treating chronic pain presents a true clinical challenge. The authors are to be commended for applying a rigorous scientific framework to the investigation of an alternative/complementary therapy of healing. In this study the primary outcome measure of efficacy was the McGill Pain Questionnaire (MPQ). Since its introduction as a novel and innovative instrument to quantify pain (Melzack, 1975), the MPQ has been used to measure pain for many conditions both acute and chronic. The responsiveness of the MPQ, specifically its ability to accurately detect change when it has occurred, has not been subjected to formal responsiveness studies. In the context of using the MPQ as a primary outcome measure in randomized controlled trials on pain treatment modalities the question is raised as to what constitutes a clinically meaningful change. Farrar et al. (2000) and Rowbotham (2001) have underscored this issue pointing out that determining and defining a clinically important change in level of pain is challenging and understudied. Abbot et al. defined an eightunit change in PRIT score as the level for analyzing significant change. We are interested in knowing how the authors chose this specific value and under what terms it was found to be clinically relevant. Pain is a multi-dimensional, complex, and subjective experience which makes evaluating it extremely challenging. The MPQ is based on three qualities of pain, namely sensory, affective, and evaluative dimensions. Formal studies on the validity of the MPQ, including factor analysis, have shown sensory and affective dimensions to be consistently demonstrated but have varied in their results suggesting between two and seven dimensions (Bailey and Davidson, 1976; Leavitt et al., 1978). This suggests that the dimensions of pain presented by the MPQ are not always clearly evident and raises the question of whether there are other dimensions of pain not considered in the construct/content of the MPQ. It is possible that a therapeutic modality such as spiritual healing affects a different aspect of the pain experience that is not assessed by the MPQ. Using this argument, one needs to find a suitable measurement tool for the modality being tested or else suffer the consequences of lacking construct validity. In other words, if the effects of spiritual healing change pain in ways other than in the sensory, affective, or evaluative aspects, then it will not likely be detected except by chance. A third concern relates to the practice of comparing grouped mean pain scores. By combining the scores of those who improved after the intervention with those who did not or with those who worsened, it is possible that an effect among a significant proportion of responders could be missed (Farrar et al., 2000). Although the authors did note (Part I) that eight subjects in the treatment group and five in the control group experienced a greater than 50% reduction in pain, the statistical significance of this difference was not determined. Finally, in future studies we would suggest coupling other clinically relevant measures, such as use of analgesics and/ or pain-related physician visits, with the complementary scales used by the authors. We recognize the inherent difficulties in undertaking comprehensive evaluations of chronic pain, and look forward to future investigations on this interesting therapy.

Spiritual healing as a therapy of chronic pain: Randomized, clinical trial [3] (multiple letters)

We read with great interest the randomized clinical trial by Abbot et al. (2001) that sought to assess the efficacy of spiritual healing in chronic pain. Measuring and treating chronic pain presents a true clinical challenge. The authors are to be commended for applying a rigorous scientific framework to the investigation of an alternative/complementary therapy of healing. In this study the primary outcome measure of efficacy was the McGill Pain Questionnaire (MPQ). Since its introduction as a novel and innovative instrument to quantify pain (Melzack, 1975), the MPQ has been used to measure pain for many conditions both acute and chronic. The responsiveness of the MPQ, specifically its ability to accurately detect change when it has occurred, has not been subjected to formal responsiveness studies. In the context of using the MPQ as a primary outcome measure in randomized controlled trials on pain treatment modalities the question is raised as to what constitutes a clinically meaningful change. Farrar et al. (2000) and Rowbotham (2001) have underscored this issue pointing out that determining and defining a clinically important change in level of pain is challenging and understudied. Abbot et al. defined an eightunit change in PRIT score as the level for analyzing significant change. We are interested in knowing how the authors chose this specific value and under what terms it was found to be clinically relevant. Pain is a multi-dimensional, complex, and subjective experience which makes evaluating it extremely challenging. The MPQ is based on three qualities of pain, namely sensory, affective, and evaluative dimensions. Formal studies on the validity of the MPQ, including factor analysis, have shown sensory and affective dimensions to be consistently demonstrated but have varied in their results suggesting between two and seven dimensions (Bailey and Davidson, 1976; Leavitt et al., 1978). This suggests that the dimensions of pain presented by the MPQ are not always clearly evident and raises the question of whether there are other dimensions of pain not considered in the construct/content of the MPQ. It is possible that a therapeutic modality such as spiritual healing affects a different aspect of the pain experience that is not assessed by the MPQ. Using this argument, one needs to find a suitable measurement tool for the modality being tested or else suffer the consequences of lacking construct validity. In other words, if the effects of spiritual healing change pain in ways other than in the sensory, affective, or evaluative aspects, then it will not likely be detected except by chance. A third concern relates to the practice of comparing grouped mean pain scores. By combining the scores of those who improved after the intervention with those who did not or with those who worsened, it is possible that an effect among a significant proportion of responders could be missed (Farrar et al., 2000). Although the authors did note (Part I) that eight subjects in the treatment group and five in the control group experienced a greater than 50% reduction in pain, the statistical significance of this difference was not determined. Finally, in future studies we would suggest coupling other clinically relevant measures, such as use of analgesics and/ or pain-related physician visits, with the complementary scales used by the authors. We recognize the inherent difficulties in undertaking comprehensive evaluations of chronic pain, and look forward to future investigations on this interesting therapy.