Reliability and validation of the joint dysfunction index as a new assessment instrument for therapeutic efficacy for Kashin-Beck disease.

The objective of this study was to evaluate the reliability and validity of the joint dysfunction index (JDI) for assessment of therapeutic efficacy for Kashin-Beck disease (KBD). In an initial survey, completed questionnaires were obtained from 276 of 281 patients (98.2 %). A follow-up survey was completed with 64 KBD patients among 276 cases. A third survey selected 60 KBD patients who underwent intra-articular injection of sodium hyaluronate in the knees ascertained from the findings of the second questionnaire. Reliability was assessed using test-retest, "split-half" reliability and Cronbach's alpha coefficient. Factor analysis and item-to-domain correlation were used to analyze validity. The coefficient of variation (CV) was used to measure the sensitivity of scale. Feasibility assessment included consideration of completion time, rate of recovery, and time of completion. Reliability analysis comprised a test-retest correlation coefficient of 0.404-0.546 and a kappa test of 0.404-0.546. Internal consistency analysis comprised a Cronbach alpha coefficient of 0.689 and a split-half coefficient of 0.677. Principal component factor analysis for validity testing extracted a common factor with a cumulative variance contribution of 45.44 %. The JDI score from 276 KBD cases revealed no significant difference associated with age, gender, education, or the body mass index. Sensitivity analysis showed that there was no significant difference between pre-treatment and post-treatment values, with a CV of 96.55-172.06 %. In conclusion, the JDI can be used to evaluate the efficacy of agents used to treat KBD.

Coronary In-Stent Restenosis: Assessment with Corrected Coronary Opacification Difference across Coronary Stents Measured with CT Angiography.

PURPOSE: To determine whether changes in coronary opacification normalized to the aorta (corrected coronary opacification [CCO]) across stents can help identify in-stent restenosis (ISR) severity with use of invasive coronary angiography as the standard of reference. MATERIALS AND METHODS: This study was approved by the institutional review board, and the requirement to obtain informed consent was waived. The authors retrospectively analyzed 106 patients (88 men, 18 women; mean age, 59.6 years ± 10.4; age range, 36-84 years) who had previously undergone stent implantation within 3 months of coronary computed tomographic (CT) angiography. Attenuation values in the coronary lumen were measured proximal and distal to the stents and normalized to the descending aorta. The CCO difference across the stent was compared with the severity of ISR. One-way analysis of variance least significant difference was used for comparison. RESULTS: A total of 141 stents were assessed. Seventy-six stents were normally patent, 18 had ISR of less than 50%, 28 had ISR of 50%-99%, and 19 were fully occluded. The median CCO differences in the four groups were 0.078, 0.163, 0.346, and 0.606, respectively. There was no significant difference between stents with an ISR of at least 50% and those with total occlusion (P = .056), although the other groups had significant differences at pairwise comparison (P < .01 for all). For stents smaller than 3 mm in diameter, the median CCO differences in the four groups were 0.086, 0.136, 0.390, and 0.471, respectively. The CCO differences across normal stents and stents with ISR of less than 50% were significantly less than those across stents with an ISR of at least 50% and those with total occlusion (P < .01 for all). There were no significant differences between stents with no ISR and those with an ISR of less than 50% (P = .821) and between stents with an ISR of at least 50% and those with an ISR of 100% (P = .836). CONCLUSION: The CCO difference across coronary stents is related to ISR severity in obstructive ISR in stents smaller than 3 mm in diameter.