***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background Diarrhea-predominant irritable bowel syndrome ( IBS-d ) significantly diminishes the health-related quality of life ( HRQOL ) of patients . Psychological and social impacts are common with many IBS-d patients reporting comorbid depression , anxiety , decreased intimacy , and lost working days . The Irritable Bowel Syndrome Quality of Life ( IBS-QOL ) question naire is a 34-item instrument developed and vali date d for measurement of HRQOL in non-subtyped IBS patients . The current paper assesses this previously-vali date d instrument employing data collected from 754 patients who participated in a r and omized clinical trial of a novel treatment , eluxadoline , for IBS-d . Methods Psychometric methods common to HRQOL research were employed to evaluate the IBS-QOL . Many of the historical analyses of the IBS-QOL validations were used . Other techniques that extended the original methods were applied where more appropriate for the current data set . In IBS-d patients , we analyzed the items and substructure of the IBS-QOL via item reduction , factor structure , internal consistency , reproducibility , construct validity , and ability to detect change . Results This study supports the IBS-QOL as a psychometrically valid measure . Factor analyses suggested that IBS-specific QOL as measured by the IBS-QOL is a unidimensional construct . Construct validity was further buttressed by significant correlations between IBS-QOL total scores and related measures of IBS-d severity including the historically-relevant Irritable Bowel Syndrome Adequate Relief ( IBS-AR ) item and the FDA ’s Clinical Responder definition . The IBS-QOL also showed a significant ability to detect change as evidence d by analysis of treatment effects . A minority of the items , unrelated to the IBS-d , performed less well by the st and ards set by the original authors . Conclusions We established that the IBS-QOL total score is a psychometrically valid measure of  HRQOL  in IBS-d patients enrolled in this study . Our analyses suggest that the IBS-QOL items demonstrate very good construct validity and ability to detect changes due to treatment effects . Furthermore , our analyses suggest that the IBS-QOL items measure a univariate construct and we believe further modeling of the IBS-QOL from an item response theory ( IRT ) approach under both non-treatment and treatment conditions would greatly further our underst and ing as item-based methods could be used to develop a short form Objectives For the measurement of  patient-reported outcomes , such as ( health-related ) quality of life , often many measurement instruments exist that intend to measure the same construct . To facilitate instrument selection , our aim was to develop a highly sensitive search filter for finding studies on measurement properties of measurement instruments in PubMed and a more precise search filter that needs less abstract s to be screened , but at a higher risk of missing relevant studies . Methods A r and om sample of 10,000 PubMed records ( 01 - 01 - 1990 to 31 - 12 - 2006 ) was used as a gold st and ard . Studies on measurement properties were identified using an exclusion filter and h and search ing . Search terms were selected from the relevant records in the gold st and ard as well as from 100 systematic review s of measurement properties and combined based on sensitivity and precision . The performance of the filters was tested in the gold st and ard as well as in two validation sets , by calculating sensitivity , precision , specificity , and number needed to read . Results We identified 116 studies on measurement properties in the gold st and ard . The sensitive search filter was able to retrieve 113 of these 116 studies ( sensitivity 97.4 % , precision 4.4 % ) . The precise search filter had a sensitivity of 93.1 % and a precision of 9.4 % . Both filters performed very well in the validation sets . Conclusion The use of these search filters will contribute to evidence -based selection of measurement instruments in all medical fields BACKGROUND Dyspepsia and irritable bowel syndrome are suitable conditions for assessment of quality of life . Their similarities justify the elaboration of a single specific question naire for the two conditions . AIMS To examine the process leading to the validation of the psychometric properties of the functional digestive disorders  quality of life question naire ( FDDQL ) . METHODS Initially , the question naire was given to 154 patients , to assess its acceptability and reproducibility , analyse its content , and reduce the number of items . Its responsiveness was tested during two therapeutic trials which included 428 patients . The question naire has been translated into French , English , and German . The psychometric validation study was conducted in France , United Kingdom , and Germany by 187 practitioners . A total of 401 patients with dyspepsia or irritable bowel syndrome , defined by the Rome criteria , filled in the FDDQL and generic SF-36 question naires . RESULTS The structure of the FDDQL scales was checked by factorial analysis . Its reliability was expressed by a Cronbach ’s α coefficient of 0.94 . Assessment of its discriminant validity showed that the more severe the functional digestive disorders , the more impaired the quality of life ( p<0.05 ) . Concurrent validity was supported by the correlation found between the FDDQL and SF-36 question naire scales . The final version of the question naire contains 43 items belonging to eight domains . CONCLUSIONS The properties of the FDDQL question naire , available in French , English , and German , make it appropriate for use in clinical trials design ed to evaluate its responsiveness to treatment among patients with dyspepsia and irritable bowel syndrome There is a growing interest of clinical and epidemiological research es in the field of functional gastrointestinal disorders in our society . Accordingly , vali date d and culturally adapted instruments are required for appropriate measurement of variables specially the quality of life . The aim of our study was the linguistic validation of the Irritable Bowel Syndrome- Quality of Life question naire ( IBS-QOL ) for Iranian IBS patients with Persian language . Following the st and ard forward-backward translation method , the IBS-QOL was translated into the Persian language and completed by 141 IBS patients . Patients also completed the  IBS Symptom Severity Scale ( IBS-SSS ) and Hospital Anxiety and Depression Scale ( HADS ) .  One-week retest was performed on 30 r and omly selected patients .  Internal consistency and test-retest reliability were assessed using Cronbach 's alpha and intraclass correlation coefficient ( ICC ) , respectively . To analyze the discriminant validity , the IBS-QOL scores was correlated to the IBS-SSS and HADS scores . According to the results , reliability analyses were acceptable for all of the IBS-QOL domains ( Cronbach 's alpha=0.68 to 0.90 and ICCs=0.77 to 0.91 ) . Discriminant validity was supported by the presence of correlations of the IBS-QOL scores with disease severity ( r = -0.628 ) , depression ( r = -0.692 ) , and anxiety ( r = -0.711 ) scores ; P < 0.001 . These results indicate that the Persian version of the IBS-QOL is a reliable instrument with sufficient psychometric requirements to assess quality of life in Iranian IBS patients with Persian language 
    Output:
    
The IBS-QOL demonstrated moderate positive evidence for internal consistency and reliability and is the best instrument based on the currently available evidence .
Conclusions Even though the IBS-QOL is currently the best instrument , there is conflicting evidence for its underlying structural validity .