Boredom in practical English language classes: a longitudinal confirmatory factor analysis-curve of factors model

The study aimed to examine temporal change of boredom in English classes (BPELC) and test the longitudinal validity of the boredom in practical English classes-revised (BPELC-R) scale via longitudinal confirmatory factor analysis-curve of factors model (LCFA-CFM) approach. This approach ensures measurement invariance of BPELC over time, deals with its second-order latent variables, and considers the assessment of inter-individual differences while experiencing the emotion. Data were collected from 412 EFL adult learners on four measurements using BPELC-R and were analyzed by Mplus with LCFA-CFM. The model fit was accepted, which indicates invariance of BPELC-R as well as the factor structure of the instrument including the factor loadings of its subscales over time. Without the consideration of LCFA of BPELC-R, as addressed in this study, any observed change of the construct in the course of language learning could be misinterpreted. Also, though the rate of change in boredom differed across individual L2 learners, they all experienced a decreasing trend over time. Furthermore, the negative association between the intercept and slope suggested that learners with higher initial levels of boredom experienced a steeper decrease over time. The decreasing pattern of boredom is discussed in light of the main theories of this construct.

Validation of a derived version of the IPF-specific Saint George’s Respiratory Questionnaire

Background Health-related quality of life (HRQL) is impaired in patients with idiopathic pulmonary fibrosis (IPF). HRQL is often measured using the St. George’s Respiratory Questionnaire (SGRQ) despite the development of an IPF-specific version (SGRQ-I). Using data from a real-world cohort of patients with IPF, we aimed to transform SGRQ into a derived version of SGRQ-I, SGRQ-Ider, to examine the cross-sectional and longitudinal validity of SGRQ-Ider and to compare SGRQ-Ider to SGRQ-I. Methods Based on results from SGRQ, SGRQ-Ider was derived applying the algorithm used to develop SGRQ-I. Of the 50 items in SGRQ, 34 items were retained in SGRQ-Ider. Response options for seven items were collapsed and minor adjustments were made to the weights of two items after correspondence with the developers of SGRQ-I. Cross-sectional validation, responsiveness and minimal clinically important difference (MCID) were assessed by comparison to other HRQL instruments, pulmonary function tests and 6-min walk test performed at baseline, 6 and 12 months. Furthermore, the association between SGRQ-Ider scores and mortality was examined. Results A total of 150 IPF patients participated and 124 completed follow-up at 12 months. SGRQ-Ider performed comparably to SGRQ-I with a high concurrent validity, good test–retest reliability and high known-groups validity. SGRQ-Ider was responsive to change in HRQL and physiological anchors. MCID of SGRQ-Ider for improvement and deterioration was 3.5 and 5.7, respectively. SGRQ-Ider scores were associated with mortality in both univariate (HR 1.82, 95% CI 1.42–2.34 per 20-point increase) and multivariate analyses (HR 1.57, 95% CI 1.20–2.05 per 20-point increase). Conclusions The SGRQ-Ider is a valid, reliable and responsive HRQL instrument in patients with IPF and has psychometric properties comparable to SGRQ-I. Thus, SGRQ results can reliably be transformed into the SGRQ-Ider. The MCID estimates were calculated for improvement and deterioration separately. Increasing SGRQ-Ider score was associated with increased mortality.

Longitudinal predictive ability of mapping algorithms: Secondary analysis of NRG Oncology/RTOG 0415.

60 Background: Mapping algorithms informing economic evaluations are often derived using baseline data from clinical trials. It is unclear if these algorithms can predict health utilities accurately in post-intervention data. Thus, this study examines the longitudinal predictive ability of mapping algorithms derived from baseline trial data and explores the factors associated with prediction errors. Methods: This methodological study utilized data from an international, multicenter, randomized controlled trial of patients with low-risk prostate cancer (PC), conducted by NRG Oncology (NCT00331773). In addition to patient demographic and clinical data, this study utilized PRO data collected at baseline and 6, 12 and 24 months post-intervention. The Expanded Prostate Cancer Index Composite (EPIC) questionnaire measures health-related quality-of-life (HRQoL) and has four domains (urinary, sexual, hormonal, and bowel) and two subdomains per domain (function and bother); EuroQOL-5D-3L (EQ5D) captures health utilities. Ordinary Least Squares (OLS) regression models were used to map EPIC scores to EQ5D utilities in the baseline data through 5-fold cross-validation. Predictive performance was tested in the post-intervention data; predicted and reported utilities were compared using t-tests, and the absolute prediction error was modeled using fixed effects, as a function of baseline demographic and clinical covariates, as well as observed and predicted EQ5D utilities. Results: A total of 267 (199) patients had complete EQ5D and EPIC domain (or subdomain) data at baseline and all subsequent assessments. In the EPIC domain sample, mean ± standard deviation observed EQ5D utility was 0.90±0.13 at baseline, 0.92±0.11 at 6 months, 0.90±0.13 at 12 months and 0.89±0.14 at 24 months. Mean absolute differences (MDs) between reported and predicted were lower for models using EPIC subdomain data compared to EPIC domain data, and generally decreased as the time of assessment increased. The mapping functions over-predicted utilities for patients in perfect health while the prediction errors were increasingly negative for lower reported EQ5D scores. According to the fixed effects model for EPIC domain data, lower observed and predicted baseline EQ5D scores, and time of assessment were significant predictors of the absolute prediction error; for EPIC subdomain data, lower observed and predicted baseline EQ5D scores, hormonal bother and function, and bowel function significantly predicted the absolute prediction error. Conclusions: This study is the first to demonstrate the longitudinal validity of EPIC questionnaire, and builds upon existing research on longitudinal validity of mapping functions. The low MDs in prediction errors in post-intervention data indicate that the mapping functions are sensitive to treatment effect, thereby increasing confidence in their use in economic evaluations in PC.

Responsiveness and longitudinal validity of the Persian version of COMI to physiotherapy in patients with non-specific chronic low back pain

Background and aimsThe Core Outcome Measures Index (COMI) is a short, self-reported questionnaire for assessing important outcomes in patients with low back pain (LBP). The present study was conducted to explore the responsiveness and longitudinal validity of the Persian COMI (COMI-P) in patients with non-specific chronic LBP.MethodsIn this prospective cohort study of patients with non-specific chronic LBP receiving physiotherapy, patients completed a booklet containing the COMI-P, Persian Functional Rating Index (FRI-P), and a visual analogue scale (VAS) for pain before and after the end of ten-sessions of physiotherapy. Patients also completed a global rating of change scale (GRCS) at the end of the physiotherapy. Responsiveness was examined by means of internal responsiveness methods [t-test, standard effect size (SES); standardized response mean (SRM), and Guyatt responsiveness index (GRI)] and external responsiveness methods [correlation with external criteria and receiver operating characteristics (ROC) curve].ResultsFifty patients with a mean age of 50.62 ± 13.8 years participated. The paired t-test showed significant changes in COMI-P scores (p < 0.001). The effect sizes for COMI-P were large (range 0.96–1.23). The score changes for the COMI-P revealed significant correlations with FRI-P (r = 0.67, p < 0.001), the VAS (r = 0.65, p < 0.001), and the GRCS (r = 0.34, p = 0.02). The COMI-P change scores showed excellent correlation with the dichotomized smallest detectable change (SDC) criterion (r = 0.83, p < 0.001). The ROC area under the curve for the COMI-P based on the dichotomized SDC criterion was perfect. The minimal clinically important change was estimated 2.15 points (sensitivity 94% and specificity 100%).ConclusionsThe COMI-P appears to have responsiveness and longitudinal validity in detecting changes after physiotherapy for non-specific chronic LBP. An improvement of 2.15 points in COMI-P total score is required to be interpreted as minimally clinically important change in individual patients.