Interpreting the Chinese version of quality of life questionnaire for functional digestive disorders.

BACKGROUND AND AIM: The Chinese version quality of life questionnaire for functional digestive disorders (Chin-FDDQL) is a useful health assessment instrument for functional dyspepsia. This study aims to identify its score interpretation for clinical practice. METHODS: Data of Chin-FDDQL from the functional dyspepsia patients (≥ 18 years) between November 2009 and April 2013 were enrolled in the 1st and 14th day. After baseline and responsiveness analysis, the single score interpretation and percentile ranks were established. The statistically reliable change was defined with effect size, standardized response mean, minimal detectable change, and others. Then the receiver operating characteristic curve analysis for health improvement was performed to define the clinically important change. RESULTS: Two hundred two functional dyspepsia patients, 150 healthy participants, and 25 missing data were enrolled for analysis. Compared with the intake patients, the discharged and healthy persons have significant better health status in all domains (P < 0.001, expect discomfort in discharged people, P = 0.142), totally contrast to missing data. The reliability for single total intake and discharge were both ± 1. Based on score distribution, the 25th, 50th, and 75th percentile ranks were 49, 58, and 66 for intake scores and 59, 65, and 72 for discharge scores, respectively. The minimal detectable change and Reliable Change Index were 6 and 11 for total score. Receiver operating characteristic analyses supported that total score changes 4 or more represented minimal clinically important improvement. CONCLUSIONS: The score interpretation system of the Chin-FDDQL could assist clinician's decision making during the therapy practice.

[Development and Evaluation of GS-SF for Gastric Stuffiness (Wei PI) Patients Based on Item Response Theory, Computerized Adaptive Testing, and Data Simiuation].

OBJECTIVE: To develop and evaluate the short version of patient reported outcomes (PROs) questionnaire for gastric stuffiness (Wei Pi) patients with modern test theory and technologies, hoping to provide testing tools for related clinical practice and scientific researches with higher quality and less administrative and response burdens. METHODS: Using descriptive study design, clinical data were collected with sociological questionnaire and previous developed full items version of PROs instrument for gastric stuffiness (Wei Pi) patients via field and online surveys between Sep 2011 and Mar 2012. The statistical analysis group identified the termination parameters firstly, and then selected items with discrimination, fitting residual, item information curve (IIC) , item characteristic curve (ICC), and the rank of computerized adaptive testing (CAT) select proportion, etc. After assumption evaluation of item response theory (IRT), IIC, ICC, difficulty coefficient distribution, items-response relation and thresholds, etc. were used for psychometric evaluation of instrument. RESULTS: A total of 331 patients [Ages: 31.99 +/- 10.29 yrs; Male: 186 (56.3%)] were enrolled in statistical analysis. The test termination criterion was Max SE = 0.2 or Max items number =16. After items selection, a 15-item short version of instrument, which contains symptoms facet (8 items) and impact facet (7 items) was generated. With good unidimensionality, local independence, and monotonicity, the IC and ICC in IRT analysis showed good working capability of the questionnaire. The difficulty coefficient distribution and items-response relation were also rational, as well as response thresholds. CONCLUSIONS: The short version of PROs instrument for adult gastric stuffiness (Wei Pi) patients was successfully developed and assessed. The instrument with good methodological and reporting quality could be used in clinical and scientific evaluating their symptoms and impact.