An initial application of computerized adaptive testing (CAT) for measuring disability in patients with low back pain

<p>Abstract</p> <p>Background</p> <p>Recent approaches to outcome measurement involving Computerized Adaptive Testing (CAT) offer an approach for measuring disability in low back pain (LBP) in a way that can reduce the burden upon patient and professional. The aim of this study was to explore the potential of CAT in LBP for measuring disability as defined in the International Classification of Functioning, Disability and Health (ICF) which includes impairments, activity limitation, and participation restriction.</p> <p>Methods</p> <p>266 patients with low back pain answered questions from a range of widely used questionnaires. An exploratory factor analysis (EFA) was used to identify disability dimensions which were then subjected to Rasch analysis. Reliability was tested by internal consistency and person separation index (PSI). Discriminant validity of disability levels were evaluated by Spearman correlation coefficient (r), intraclass correlation coefficient [ICC(2,1)] and the Bland-Altman approach. A CAT was developed for each dimension, and the results checked against simulated and real applications from a further 133 patients.</p> <p>Results</p> <p>Factor analytic techniques identified two dimensions named "body functions" and "activity-participation". After deletion of some items for failure to fit the Rasch model, the remaining items were mostly free of Differential Item Functioning (DIF) for age and gender. Reliability exceeded 0.90 for both dimensions. The disability levels generated using all items and those obtained from the real CAT application were highly correlated (i.e. > 0.97 for both dimensions). On average, 19 and 14 items were needed to estimate the precise disability levels using the initial CAT for the first and second dimension. However, a marginal increase in the standard error of the estimate across successive iterations substantially reduced the number of items required to make an estimate.</p> <p>Conclusion</p> <p>Using a combination approach of EFA and Rasch analysis this study has shown that it is possible to calibrate items onto a single metric in a way that can be used to provide the basis of a CAT application. Thus there is an opportunity to obtain a wide variety of information to evaluate the biopsychosocial model in its more complex forms, without necessarily increasing the burden of information collection for patients.</p

?2 adrenoceptor (ADRB2) pharmacogenetics and cardiovascular phenotypes during laryngoscopy and tracheal intubation

PubMed: 17132602Pharmacogenetics is the study of genetic variations that cause a variable drug response characterized by alteration in drug metabolism or in pharmacodynamics. The polymorphisms in genes encoding receptors relevant to treatment cause variation in sensitivity to many drugs. ?2 Adrenoceptor genetic variation contributes to regulation of blood pressure and hemodynamic changes by mediating peripheral vasodilatation. Laryngoscopy and tracheal intubation associated with hemodynamic changes. Although there are four nonsynomic single-nucleotide polymorphisms (SNPs) of ?2 adrenoceptor gene, codon 16 (Arg16Gly) and codon 27 (Gln27Glu) SNPs are both common and functionally important. In this paper, the authors investigated the ?2 adrenoceptor Gly16 and Glu27 SNPs in response to drugs relevant to anesthesia and how these SNPs impacted upon the cardiovascular phenotypes. The authors measured arterial systolic and diastolic blood pressure, heart rate, and rate-pressure product before induction of anesthesia and 1 min following laryngoscopy and tracheal intubation. Genomic DNA was amplified and genotyped using allele-specific polymerase chain reaction (ASPCR) and restriction fragment length polymorphism (RFLP) assays, respectively. When the authors compared hemodynamic results according to genotypes, the patients with Gln homozygote allele at codon 27 exhibited significant increase of heart rate than patients with Glu allele after laryngoscope and tracheal intubation. Copyright © American College of Toxicology

Quality-of-life in insect venom allergy: validation of the Turkish version of the “Vespid Allergy Quality of Life Questionnaire” (VQLQ-T)

Purpose: “Vespid Allergy Quality of Life Questionnaire (VQLQ)” has been used to assess psychological burden of disease. The aim of this study was to evaluate validity, reliability and responsiveness to interventions of the Turkish version. Methods: The Turkish language Questionnaire (VQLQ-T) was administered to 81 patients with bee allergy and 65 patients with vespid allergy from different groups to achieve cross-sectional validation. To establish longitudinal validity, the questionnaire was administered to 36 patients treated with venom immunotherapy. Results: The cross-sectional validation in patients with vespid venom allergy showed a correlation coefficient of 0.97 (Cronbach ?). Spearman’s correlation coefficient of the pretreatment VQLQ-T score with Expectation of Outcome (EoO) questionnaire score was 0.55 (p < 0.001). After treatment, correlation between VQLQ-T score and EoO score was 0.64 (p = 0.003) in these patients. The cross-sectional instrument validation for non-beekeepers with bee venom allergy yielded a correlation coefficient of 0.96 (Cronbach ?). Spearman’s correlation coefficient between pretreatment VQLQ-T score and EoO score was 0.47 (p < 0.001) and after treatment, correlation between VQLQ-T score and EoO score was 0.78 (p = 0.008) in these patients. These findings indicate cross-sectional validity of VQLQ-T. In the longitudinal validation, there was a positive correlation between EoO and VQLQ-T with a correlation coefficient of 0.562 (p < 0.001). While mean (±SD) VQLQ-T score was 5.27 (±1.29) in pretreatment, it was 2.78 (±1.01) after treatment (p < 0.001). The correlation between the mean change in VQLQ-T score and the mean change in EoO score was 0.42 (p = 0.011). Conclusions: The Turkish version of VQLQ-T enables measurement of Quality of Life (QoL) in patients with either vespid or bee venom allergy. Furthermore, responsiveness of this instrument demonstrates the questionnaire’s ability to detect changes over time. © 2016, The Author(s)