Clinimetric Validation of the Assessment of Spondyloarthritis International Society Health Index in Patients With Radiographic Axial Spondyloarthritis in Ixekizumab Trials.

OBJECTIVE: To assess test-retest reliability, construct validity, known groups discrimination, and responsiveness of the Assessment of the SpondyloArthritis international Society Health Index (ASAS HI) to evaluate functioning, disability, and health in patients with radiographic axial spondyloarthritis (r-axSpA). METHODS: Data were generated from 2 randomized, placebo-controlled, active-controlled phase III ixekizumab studies (COAST-V, N = 341; COAST-W, N = 316). Assessments included the following: test-retest reliability (ie, intraclass correlation coefficients [ICCs] between ASAS HI scores at screening and baseline), construct validity (ie, Spearman correlation with standard r-axSpA outcome measures), known groups discrimination (ie, 1-way ANOVA comparing the ASAS HI with different disease activity categories, measured by the Ankylosing Spondylitis Disease Activity Score [ASDAS]), and responsiveness (ie, Spearman correlation between changes in the ASAS HI and changes in the Bath Ankylosing Spondylitis Functional Index [BASFI], the Bath Ankylosing Spondylitis Disease Activity Index [BASDAI], the ASDAS, and the Patient Global Assessment [PtGA] as well as ANOVA comparing changes in the ASAS HI with various responder categories). RESULTS: The ICC for test-retest reliability was 0.78 for COAST-V and 0.76 for COAST-W, indicating adequate agreement. Moderate-to-large correlations (r = 0.40-0.61) were observed between the ASAS HI and the BASDAI. Statistically significant differences (all P < 0.001) between mean ASAS HI scores were observed for subgroups based on ASDAS-defined disease activity categories at baseline and week 16. Moderate-to-large correlations existed between changes in the ASAS HI and the BASFI, BASDAI, ASDAS, and PtGA from baseline to week 16. The ASAS HI differentiated statistically (P < 0.001) between ASAS, BASDAI, and ASDAS response groups. CONCLUSION: The ASAS HI demonstrated reliability, construct validity, known groups discrimination, and responsiveness in adults with r-axSpA in 2 clinical trials.

Development of one general and six country-specific algorithms to assess societal health utilities based on ASAS HI.

Objective: Health utilities represent preference values that persons attach to health states. This study aims to develop one general and six country-specific algorithms to calculate societal preference values for health of patients with spondyloarthritis (SpA), as assessed by the disease-specific Assessment of SpondyloArthritis international Society Health Index (ASAS HI). Methods: A survey was performed in random population samples from six European countries. In a best-worst choice experiment, subjects were asked to indicate repeatedly which of 4 random aspects of the 17-item ASAS HI was were most and least important. Bayesian analysis provided the relative importance of each of the 17 items. To rescale the relative importance scores on the absolute utility scale between 0 and 1, participants additionally completed two lead time trade-off experiments, one for 'severe SpA' and one for 'best health' without SpA. Six country-specific algorithms and one general algorithm were derived. The general algorithm was tested in 199 patients with axial SpA (axSpA). Results: 3039 subjects, mean age 47 years (SD 15) and 52% female completed the experiments. The population's health utility value for SpA varied between - 0.24 for 'worst' SpA (country range -0.35 to 0.03), and 0.88 for 'best' health (country range 0.81 to 0.90). Among 199 patients with axSpA, the mean utility was 0.36 (SD 0.30, range -0.24 to 0.88) and discriminated well between patients having high (Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) ≥ 4) or low (BASDAI < 4) disease activity (0.18 (SD 0.24) vs 0.51(SD 0.27), p<0.01). Conclusion: One general and six country-specific algorithms are available to convert scores from the ASAS HI into disease-specific societal utility values.

Electronic assessment of disease activity and functioning in patients with axial spondyloarthritis: challenges and unmet needs.

The dynamic clinical course of rheumatic conditions indicates a need for regular collection of information on health status to monitor disease activity and functional status. Patient-reported outcomes measures (PROMs) are playing a key role in the evaluation of symptoms and functioning and health, and are crucial in the initiation of treatment in those patients. In recent years, electronic assessments of PROMs (so called ePROMs) have been introduced. This report summarises some of the rationale, opportunities, and results using ePROMs in patients with spondyloarthritis (SpA).

Field assessment of guar gum stabilized microscale zerovalent iron particles for in-situ remediation of 1,1,1-trichloroethane.

A pilot injection test with guar gum stabilized microscale zerovalent iron (mZVI) particles was performed at test site V (Belgium) where different chlorinated aliphatic hydrocarbons (CAHs) were present as pollutants in the subsurface. One hundred kilograms of 56µm-diameter mZVI (~70gL(-1)) was suspended in 1.5m(3) of guar gum (~7gL(-1)) solution and injected into the test area. In order to deliver the guar gum stabilized mZVI slurry, one direct push bottom-up injection (Geoprobe) was performed with injections at 5 depths between 10.5 and 8.5m bgs. The direct push technique was preferred above others (e.g. injection at low flow rate via screened wells) because of the limited hydraulic conductivity of the aquifer, and to the large size of the mZVI particles. A final heterogeneous distribution of the mZVI in the porous medium was observed explicable by preferential flow paths created during the high pressure injection. The maximum observed delivery distance was 2.5m. A significant decrease in 1,1,1-TCA concentrations was observed in close vicinity of spots where the highest concentration of mZVI was observed. Carbon stable isotope analysis (CSIA) yielded information on the success of the abiotic degradation of 1,1,1-TCA and indicated a heterogeneous spatio-temporal pattern of degradation. Finally, the obtained results show that mZVI slurries stabilized by guar gum can be prepared at pilot scale and directly injected into low permeable aquifers, indicating a significant removal of 1,1,1-TCA.

Developing and validating an index for measuring health in patients with ankylosing spondylitis.

OBJECTIVES: The impact of disease on functioning is the essential information for clinicians when reporting on health problems of individuals. The International Classification of Functioning, Disability and Health (ICF) is a comprehensive and universally accepted model to classify and describe functioning, disability and health in a systematic way. The objective of this article is to outline the development and validation of a health index for patients with AS based on the ICF as a use case. METHODS: The project is a combined effort of the Assessment of SpondyloArthritis International Society, the ICF Research Branch of the World Health Organization (WHO) Collaboration Centre of the Family of International Classifications and the WHO. There are five steps in the development and validation of the health index for patients with AS: (i) development of an item pool; (ii) identification of candidate items; (iii) item selection; (iv) item reduction; and (v) creation of a final version. Consensus about items that have to be part will be reached in a final consensus conference. RESULTS: During a meeting in February 2009, we coordinated the development process of the health index for patients with AS. The results of this investigation will be the health index for patients with AS. CONCLUSION: The goal of developing a health index for patients with AS based on the ICF is very much in line with the broader goal of the WHO to define health indices to ensure the comparability of them within the framework of the ICF.