Cross-cultural adaptation and validation of the Slovenian version of the Core outcome measures index for low back pain.

BACKGROUND: To conduct a cross-cultural adaptation and validation of the Core Outcome Measures Index (COMI) in the Slovenian language, for use in patients with low back pain. METHODS: The English version of COMI was translated into Slovene following established guidelines. Three hundred fifty-three patients with chronic low back pain were recruited from the Orthopedic clinic department of a tertiary care teaching institution. Data quality, construct validity, responsiveness, and test-retest reliability of the COMI were assessed. RESULTS: The questionnaire was generally well accepted with no missing values. The majority of items exhibited only mild ceiling effects (below 20.0%) and somewhat more prominent floor effects, which were similar to previous studies (4.5-78.8%). Correlations with Oswestry Disability Index (ODI) were high (ρ = 0.76 between overall COMI and ODI scores), suggesting that the Slovene version of COMI had high construct validity. Additionally, the Slovene version of COMI successfully captured surgical patients' improvement in their low back problem after surgery (overall COMI score change: Z = - 9.34, p < .001, r = - 0.53) and showed acceptable test-retest reliability (ICC = 0.86). CONCLUSIONS: The Slovene version of COMI showed good psychometric properties, comparable to those of previously tested language versions. It represents a valuable instrument for the use in future domestic and multicenter clinical studies.

Cross-cultural adaptation, reliability, and validity of the German version of the Pain Catastrophizing Scale.

OBJECTIVE: In patients with chronic pain, catastrophizing is a significant determinant of self-rated pain intensity and disability. The Pain Catastrophizing Scale (PCS) was developed to assist with both treatment planning and outcome assessment; to date, no German version has been validated. METHODS: A cross-cultural adaptation of the PCS into German was carried out, strictly according to recommended methods. A questionnaire booklet containing the PCS, visual analogue scales (numeric rating scale) for pain intensity and general health, the ZUNG self-rating depression scale, the Modified Somatic Perception Questionnaire (MSPQ), the Fear Avoidance Beliefs Questionnaire (FABQ), and the Roland-Morris (RM) disability questionnaire was completed by 111 patients with chronic low back pain (mean age, 49 years), 100 of which also completed it again 7 days later. RESULTS: Cronbach's alpha (internal reliability) for the three subsections of the PCS--helplessness, magnification, rumination--and for the whole questionnaire (PCSwhole) were .89, .67, .88, and .92, respectively. The intraclass correlation coefficients of agreement for the reproducibility were .81, .67, .78, and .80, respectively. The PCSwhole scores correlated with the other scores as follows: pain intensity r=.26, general health r=-.29, ZUNG r=.52, MSPQ r=.53, FABQactivity r=.51, FABQwork r=.61 and RM r=.57. Factor analysis revealed three factors, with an almost identical factor structure to that reported in previous studies. CONCLUSION: The psychometric properties of our German version of the PCS were comparable to those reported in previous studies for the original English version. It represents a valuable tool in the assessment of German-speaking chronic low back pain patients.

Association between catastrophizing and self-rated pain and disability in patients with chronic low back pain.

BACKGROUND: Catastrophizing plays an important role in models of pain chronicity, showing a consistent correlation with both pain intensity and disability. It is conceivable that these associations are mediated or confounded by other psychological attributes. OBJECTIVE: To examine the relative influence of catastrophizing and other psychological variables on pain and disability in patients with chronic low back pain. METHODS: Seventy-eight patients completed the Pain Catastrophizing Scale, Roland Morris Disability Questionnaire, Fear-Avoidance Beliefs Questionnaire (work/activity), Modified Somatic Perception Questionnaire, Modified Zung Depression Scale, and Pain Intensity scale. RESULTS: Catastrophizing was significantly correlated with both Pain intensity and Roland and Morris Disability, and with all other psychological variables (all p < 0.001). However, multiple regression analyses showed that Catastrophizing explained no significant variance in Pain intensity beyond that explained by the unique contributions of Modified Somatic Perception and Fear-Avoidance Beliefs (work) and explained no further variance in Disability beyond that explained by the unique contributions of Fear-Avoidance Beliefs (work) and Depression. CONCLUSION: These findings are consistent with previous models proposing that negative psychological attributes are associated with greater perceptions of pain and disability. Nonetheless, our study indicates that measures of catastrophizing show notable measurement overlap in multivariate models.