2014, Article / Letter to editor (Journal of Occupational Rehabilitation, vol. 24, iss. 3, (2014), pp. 419-424)PURPOSE: Patients with chronic Whiplash Associated Disorders (WAD) report symptoms and disability. Neither the relationship between self-reported disability and functional capacity, nor its predictors have been investigated in patients with WAD. This was the purpose of this study. METHOD: This was a cross-sectional study. Participants were patients with WAD on sick leave. Self-reported disability was assessed with the Neck Disability Index (NDI). Functional capacity was assessed with a six-item neck functional capacity evaluation (FCE). Correlation coefficients were used to express the relationship between NDI (total and items) and FCE. Multivariate linear regression analyses were performed to identify independent predictors of NDI and FCE. RESULTS: Forty patients were measured, of whom 18 (45 %) were male. Mean age was 33 years, median duration of complaints was 12 months, and 75 % had a pending insurance claim. Correlations between NDI and FCE tests varied from -0.39 to -0.70. Independent predictors of NDI were pain intensity and a pending claim, explaining 43 % of the variance. independent predictors of fce were ndi, gender, and pain intensity, explaining 20-55 % of the variance. CONCLUSIONS: Self-reported disability and functional capacity are related but different. Both can part be predicted by pain intensity. A pending claim can predict higher self-reported disability. Both constructs are complementary and are recommended to determine disability in patients with WAD comprehensively.
2013, Article / Letter to editor (Spine, vol. 38, iss. 25, (2013), pp. E1608-15)STUDY DESIGN: Systematic review. OBJECTIVE: To evaluate the validity of instruments that claim to detect submaximal capacity when maximal capacity is requested in patients with chronic nonspecific musculoskeletal pain. SUMMARY OF BACKGROUND DATA: Several instruments have been developed to measure capacity in patients with chronic pain. The detection of submaximal capacity can have major implications for patients. The validity of these instruments has never been systematically reviewed. METHODS: A systematic literature search was performed including the following databases: Web of Knowledge (including PubMed and Cinahl), Scopus, and Cochrane. Two reviewers independently selected the articles based on the title and abstract according to the study selection criteria. Studies were included when they contained original data and when they objectified submaximal physical or functional capacity when maximal physical or functional capacity was requested. Two authors independently extracted data and rated the quality of the articles. The included studies were scored according to the subscales "Criterion Validity" and "Hypothesis Testing" of the COSMIN checklist. A Best Evidence Synthesis was performed. RESULTS: Seven studies were included, 5 of which used a reference standard for submaximal capacity. Three studies were of good methodological quality and validly detected submaximal capacity with specificity rates between 75% and 100%. CONCLUSION: There is strong evidence that submaximal capacity can be detected in patients with chronic low back pain with a lumbar motion monitor or visual observations accompanying a functional capacity evaluation lifting test.
2013, Article / Letter to editor (Spine, vol. 38, iss. 25, (2013), pp. E1608-15)STUDY DESIGN: Systematic review. OBJECTIVE: To evaluate the validity of instruments that claim to detect submaximal capacity when maximal capacity is requested in patients with chronic nonspecific musculoskeletal pain. SUMMARY OF BACKGROUND DATA: Several instruments have been developed to measure capacity in patients with chronic pain. The detection of submaximal capacity can have major implications for patients. The validity of these instruments has never been systematically reviewed. METHODS: A systematic literature search was performed including the following databases: Web of Knowledge (including PubMed and Cinahl), Scopus, and Cochrane. Two reviewers independently selected the articles based on the title and abstract according to the study selection criteria. Studies were included when they contained original data and when they objectified submaximal physical or functional capacity when maximal physical or functional capacity was requested. Two authors independently extracted data and rated the quality of the articles. The included studies were scored according to the subscales "Criterion Validity" and "Hypothesis Testing" of the COSMIN checklist. A Best Evidence Synthesis was performed. RESULTS: Seven studies were included, 5 of which used a reference standard for submaximal capacity. Three studies were of good methodological quality and validly detected submaximal capacity with specificity rates between 75% and 100%. CONCLUSION: There is strong evidence that submaximal capacity can be detected in patients with chronic low back pain with a lumbar motion monitor or visual observations accompanying a functional capacity evaluation lifting test.