Validation of the Brief Pain Inventory in Patients With Low Back Pain.

STUDY DESIGN: Cross-sectional psychometric testing in a sample of patients with low back pain (LBP). OBJECTIVE: The aim of this study was to examine the construct, convergent, and discriminative validity of the Brief Pain Inventory (BPI) in patients with LBP. SUMMARY OF BACKGROUND DATA: The BPI was originally developed to assess cancer pain. Currently, it is commonly used to measure pain intensity and pain interference in patients with malignant or nonmalignant pain. However, the two-factor construct of the BPI has not been confirmed in an LBP population. METHODS: A total of 271 patients with LBP completed the BPI and Oswestry Disability Index (ODI) questionnaires. The construct validity (i.e., the two-factor structure: intensity scale and interference scale) of the BPI was determined by confirmatory factor analysis. The convergent validity was investigated by examining the relationships between the BPI scales and the ODI scores. The discriminative validity of the BPI was examined by testing if the BPI scale scores differed among groups of patients with different levels of disability. RESULTS: Confirmatory factor analysis partially confirmed the two-factor structure of the BPI for use in patients with LBP. The convergent validity of the BPI was supported by its moderate correlation between the interference scale and the ODI score (ρ = 0.66, P < 0.001), and by its low correlation between the intensity scale and the ODI score (ρ = 0.39, P < 0.001). Finally, both the intensity scale and the interference scale discriminated among patients with varying levels of disability (both P < 0.001). CONCLUSION: The two-factor structure of the BPI as a measure of pain intensity and interference in patients with LBP was partially confirmed. Furthermore, our results lend some supports to the convergent validity and discriminative validity of the BPI. LEVEL OF EVIDENCE: N/A.

The Effects of Extracorporeal Shock Wave Therapy in Patients with Coccydynia: A Randomized Controlled Trial.

UNLABELLED: Coccydynia is pain in the coccygeal region, and usually treated conservatively. Extracorporeal shock wave therapy (ESWT) was incorporated as non-invasive treatment of many musculoskeletal conditions. However, the effects of ESWT on coccydynia are less discussed. The purpose of this study is to evaluate the effects of ESWT on the outcomes of coccydynia. Patients were allocated to ESWT (n = 20) or physical modality (SIT) group (n = 21) randomly, and received total treatment duration of 4 weeks. The visual analog scale (VAS), Oswestry disability index (ODI), and self-reported satisfaction score were used to assess treatment effects. The VAS and ODI scores were significantly decreased after treatment in both groups, and the decrease in the VAS score was significantly greater in the ESWT group. The mean proportional changes in the ODI scores were greater in the ESWT group than in the SIT group, but the between-group difference was not statistically significant. The patients in the ESWT group had significantly higher subjective satisfaction scores than SIT group. We concluded that ESWT is more effective and satisfactory in reducing discomfort and disability caused by coccydynia than the use of physical modalities. Thus, ESWT is recommended as an alternative treatment option for patients with coccydynia. TRIAL REGISTRATION: ClinicalTrials.gov NCT02313324.

Comparison of the test-retest reliability of the balance computerized adaptive test and a computerized posturography instrument in patients with stroke.

OBJECTIVE: To compare the test-retest reliabilities of the scores of the Balance Computerized Adaptive Test (CAT) and the Biodex Balance System in patients with stroke. DESIGN: A repeated-measures design (at a 1-wk interval) was used to examine the test-retest reliabilities of the scores of the Balance CAT and the Biodex Balance System. SETTING: One rehabilitation unit in a local hospital. PARTICIPANTS: Patients (N=50) with stroke for more than 6 months and undergoing outpatient rehabilitation completed the Balance CAT and the eyes open (EO)/closed (EC) tests, but only 17 patients finished the Limit of Stability (LOS) test because they were unable to reach all the targets. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The Balance CAT and 2 computerized tests of the Biodex Balance System, namely the EO/EC test and the LOS, were used to evaluate balance function. RESULTS: The test-retest reliabilities of the scores of the Balance CAT (Pearson r=.92, minimal detectable change [MDC] percent=12.8%) was excellent. Those of the EO/EC and LOS tests were poor to good (Pearson r=.56-.85, MDC%=50.8%-126.9%). CONCLUSIONS: The test-retest reliabilities of the scores of the Balance CAT were sufficient for assessing balance function in patients with stroke. Moreover, the test-retest reliabilities of the scores of the Balance CAT, one of the functional balance measures, were superior to those of the Biodex Balance System, 1 type of computerized posturography instrument. Therefore, the Balance CAT may be a more reliable measure for clinicians and researchers to use in assessing the balance function of patients with stroke for more than 6 months.