Introduction The construct validity of the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH) has previously been questioned. The purpose of this study was to evaluate the measurement properties of the Finnish version of the DASH for assessing disability in patients with hand complaints using Rasch Measurement Theory. Methods A cohort of 193 patients with typical hand and wrist complaints were recruited at a surgery outpatient clinic. The DASH scores were analysed using the Rasch model for differential item functioning, unidimensionality, fit statistics, item residual correlation, coverage/targeting and reliability. Results In the original DASH questionnaire, the item response thresholds were disordered for 2 of 30 of the items. The item fit was poor for 9 of 30 of the items. Unidimensionality was not supported. There was substantial residual correlation between 87 pairs of items. Item reduction (chi square 95, degrees of freedom 50, p < 0.001) and constructing two testlets led to unidimensionality (chi square 0.64, degrees of freedom 4, p = 0.96). Person separation index was 0.95. The testlets had good fit with no differential item functioning towards age or gender. Conclusion Unidimensionality of the original Finnish version of the DASH was not supported, meaning the questionnaire seems to gauge traits other than disability alone. Hence, the clinician must be careful when trying to measure change in patients’ scores. Item reduction or the creation of testlets did not lead to good alternatives for the original Finnish DASH. Differential item functioning showed that the original Finnish scale exhibits minor response bias by age in one item. The original Finnish DASH covers different levels of ability well among typical hand surgery patients.

Introduction Previously, it has been noted that there is no predictive value of MRI findings of degenerative changes of the lumbar spine in asymptomatic individuals in the development of first time episodes of low back pain (LBP). In a population-based cohort, this study addressed if radiographic findings on MRI in asymptomatic individuals are predictive in the development of first-time episodes of LBP and pain severity. Materials and Methods A prospective, radiographic and clinical study was performed in 248 asymptomatic individuals of Southern Chinese origin with no previous history of LBP. All subjects underwent sagittal MRI assessment of the lumbar spine. Assessment of disk degeneration was based on the Schneiderman et al radiographic criteria to determine the presence, extent, and severity of disk degeneration. A summated degenerative disk disease (DDD) score of the lumbar spine was obtained, representing the global severity of disk degeneration. The presence of disk bulge/extrusion, Schmorl's nodes (SN), and Modic changes were also noted. At 2 years minimum follow-up, clinical assessment was performed and subject demographics were noted to identify the development of LBP and functional outcome status (e.g., Oswestry disability index). Results There were 93 males and 155 females with a mean age at MRI of 42.9 years ( ± SD = 7.6, range: 21.1 to 54.6 years). Overall presence of disk degeneration, disk space narrowing, and disk bulge/extrusion was noted in 60.5, 19.0, and 34.3% of individuals, respectively. The mean DDD score was 2.2 ( ± SD = 2.9; range: 0 to 12). SN and Modic changes were noted in 10.5 and 1.2%, respectively. Clinical follow-up was performed at a mean of 4.3 years ( ± SD = 1.9, range: 2.2 to 10.0 years). The incidence rate of first-time LBP episodes on clinical follow-up was 34.7%. The mean age of first-time LBP episode was 44.8 years ( ± SD = 8.5; range: 22 to 57 years). Regression modeling noted that the presence of disk bulge/extrusion (OR: 2.37; 95% CI, 1.30–4.32) and increasing DDD score (>7 score OR: 6.90; 95% CI, 1.86–25.52), in particular if segments involved the mid lumbar region, demonstrated significant predictive utility for developing first-time LBP episode. DDD score and disk bulge/extrusion were found predictive to the severity of LBP, greater functional disability, and increased frequency of future LBP episodes (p < 0.05). Conclusion This large-scale prospective study substantiates that spinal changes are found in asymptomatic subjects on MRI; however, the “global severity” of disk degeneration on initial MRI may be predictive in the development of first-time LBP episodes. I confirm having declared any potential conflict of interest for all authors listed on this abstract No Disclosure of Interest None declared

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