Differentiating sensory and affective-sensory pain descriptions in patients undergoing magnetic resonance imaging for persistent low back pain

The study design is a cross-sectional survey with psychometric analysis. The objective is to determine the validity of a modified version of the Short-Form McGill Pain Questionnaire (SF-MPQ). The SF-MPQ has been widely used to differentiate between reports of sensory and affective pain. The validity of this instrument to reflect independence between these constructs remains unclear. The SF-MPQ, the Roland-Morris Questionnaire (RM) and a measure of current pain intensity were completed by 373 patients undergoing lumbar magnetic resonance imaging (MRI). Four hypothesized factor structures for the SF-MPQ (three 2-factor and one 1-factor solution) were tested using confirmatory factor analysis. A modified 2-factor solution (MSF-MPQ) containing 3 items labeled sensory and 5 items labeled affective-sensory had the best degree of fit. Correlations between factors were substantially lower for the modified 2-factor solution (0.48) than for previously described 2-factor solutions (0.88 and 0.92) indicating a higher degree of independence between these factors. Correlations with measures of pain intensity and the RM were significant, but slightly lower, for the subscales of the modified 2-factor solution (0.26-0.40) than for the subscales of the previously described 2-factor solutions (0.34-0.45). The MSF-MPQ can be used as a brief tool to differentiate the language used to describe pain in patients who are undergoing lumbar MRI. The evidence indicates that this clinical tool can be used to categorize how these patients describe their pain and potentially may be very valuable in determining the optimal course of treatment.     

The use of the McGill Pain Questionnaire in assessing arthritis pain

Responses to the McGill Pain Questionnaire (MPQ) were described in two samples of arthritis patients, an inpatient group (n = 94) and an outpatient group (n = 94). Subjects in both samples used a similar set of sensory words to describe their arthritis pain. The inpatient sample, however, used affective words of higher intensity than the outpatient sample. Because the two samples came from a common population, they were combined and exploratory factor analyses using principal component analysis with first oblique and then orthogonal rotations were performed. The analysis yielded 6 factors that accounted for 58.3% of the variance in the sample. Clear sensory factors, an affective factor and an evaluative factor were identified. The study provides preliminary evidence that a substantial affective dimension underlies the MPQ responses of arthritis patients and confirms the parsimony of a 3-factor solution for the questionnaire.     

Some empirical evidence regarding the validity of the Spanish version of the McGill Pain Questionnaire (MPQ-SV)

Despite the fact that the McGill Pain Questionnaire (MPQ) is a useful pain assessment tool with widespread acceptance, empirical analyses have questioned its validity because they have not consistently supported the three a priori factors that guided its construction. The Spanish version that has followed the most systematic and rigorous reconstruction process (Lázaro C, Bosch F, Torrubia R, Banos JE. The development of a Spanish Questionnaire for assessing pain: preliminary data concerning reliability and validity. Eur J Psychol Assess, 1994;10:145-151) lacks evidence to support its construct validity. In the present study, the internal structure of the Spanish version of the McGill Pain Questionnaire (Lázaro C, Bosch F, Torrubia R, Banos JE. The development of a Spanish Questionnaire for assessing pain: preliminary data concerning reliability and validity. Eur J Psychol Assess, 1994;10:145-151) was examined in a sample of 202 acute pain patients and 207 chronic pain patients. Confirmatory factor analyses were carried out to compare alternative models postulating different internal structures (one-factor model, the classic three-factor model, and the semantic model inspired by the alternative structure found by Donaldson in 1995 (Donaldson GW. The factorial structure and stability of the McGill Pain Questionnaire in patients experiencing oral mucositis following bone marrow transplantation. Pain 1995;62:101-109)). Results from the LISREL CFA analysis indicated that the semantic model fitted better than the other models. On the other hand, intercorrelations between scales were smaller than the reliability indexes. In relation to concurrent evidence, significant correlations (0.001) were found between each subscale and the criteria measurements of every pain dimension. Only the affective subscale presented discriminant validity. Evidence supports the validity of the affective and sensory subscales but not the evaluative scale.     

Finding a solution to the problem of pain: conceptual formulation and the development of the Pain Solutions Questionnaire (PaSol)

We report the development of the Pain Solutions Questionnaire (PaSol), an instrument designed to measure assimilative (efforts at changing or solving pain) and accommodative (accepting that pain cannot be solved, and changing life goals) responses to the problems associated with pain. Data were collected from 476 adults suffering from chronic pain. Exploratory and confirmatory factor analyses resulted in a 14-item instrument with an adequate oblique 4-factor structure: (1) Solving Pain scale (4 items), (2) Meaningfulness of Life Despite Pain scale (5 items), (3) Acceptance of the Insolubility of Pain scale (3 items), and (4) Belief in a Solution scale (2 items). The validity of the PaSol was further tested by its value in explaining disability and affective distress after controlling for the effects of the demographic characteristics and pain severity. The Meaningfulness of Life Despite Pain scale was important in explaining disability and affective distress. The Solving Pain scale had a unique and independent contribution in explaining affective distress. Results are discussed in terms of how a persistence in assimilative coping, even though the pain problem is insoluble, may increase hypervigilance, catastrophizing, distress and disability.     

Factor Structure of the Beck Depression Inventory-II in patients With chronic pain

OBJECTIVES: To examine the factor structure of the Beck Depression Inventory version II (BDI-II) in patients seeking treatment for chronic pain, using exploratory and confirmatory factor analysis and provide comparative data for use with similar patient populations. In addition, to consider the utility of using BDI-II subscale scores to further inform the management of patients with chronic pain. METHODS: Phase I involved analysis of responses to the BDI-II by 1227 patients assessed for a pain management program. The sample data was split into 2 halves. A series of exploratory factor analyses on the first half suggested 2 factors. Confirmatory factor analysis was then used on the second half to confirm goodness-of-fit for this 2-factor solution and compare with a 1-factor solution and factor models presented in the BDI-II handbook derived on student and psychiatric outpatient populations. Comparison was also made of derived factor scores between this pain clinic sample and the normative psychiatric outpatient and student samples. In the second phase, longitudinal data on a further 269 patients who had completed the pain management program was used to examine the amount of variance in pain and disability outcomes accounted for by total BDI-II and 2-factor subscale scores at assessment. RESULTS: Two correlated factors incorporating 18 items from the BDI-II gave good goodness-of-fit (0.916). Factor 1 loaded heavily onto negative cognitions about the self plus mood symptoms, factor 2 onto changes in behavior and activity plus low mood. Summed scores on factor 1 from pain clinic patients were very significantly lower than for psychiatric outpatients, indicating less negative cognitions about the self, and very significantly higher than for a student sample. Pain clinic patient scores on factor 2 were very significantly higher than those for both psychiatric outpatients and students, indicating more reporting of behavior change and affective symptoms. Subscale scores accounted for a small but significant amount of variance in both pain and disability at follow-up, with each scale predicting in opposite directions. Total BDI-II scores predicted similar amounts of variance in disability at follow-up, but were not significantly associated with pain at follow-up. DISCUSSION: Results are consistent with studies using previous versions of the BDI in suggesting that 2-factor scores may be more clinically useful in the assessment of patients referred with chronic pain.