The evidence supports the WPAI as having test-retest reliability ( reproducibility ) over time ; convergent validity , as indicated by moderate correlations with measures of quality of life and moderate-to-strong correlations with measures of disease activity ; known-groups validity , as indicated by differences in WPAI scores between patients with active and inactive disease ; ability ( sensitivity ) to detect change , as indicated by substantial improvement in scores for patients who achieve remission , accompanied by substantial worsening of scores for patients who relapse ; and , responsiveness to treatment , with improvements in scores following treatments that reduce disease activity .
Patients with ulcerative colitis , a type of inflammatory bowel disease , report negative impacts of disease symptoms on work-related outcomes , including absenteeism and presenteeism .
As a way to better underst and the impact of this disease and its treatment on work-related outcomes , the current review examines the use of the Work Productivity and Activity Impairment Question naire ( WPAI ) , a patient-reported outcomes measure of absenteeism , presenteeism , and impairment in other activities , in studies of patients with ulcerative colitis .
This review assesses the measurement properties of the WPAI in this patient population : its reliability , construct validity , ability to detect change , and responsiveness to effective treatments .
Measurement of health status. Ascertaining the minimal clinically important difference.
In recent years quality of life instruments have been featured as primary outcomes in many r and omized trials . One of the challenges facing the investigator using such measures is determining the significance of any differences observed , and communicating that significance to clinicians who will be applying the trial results . We have developed an approach to elucidating the significance of changes in score in quality of life instruments by comparing them to global ratings of change . Using this approach we have established a plausible range within which the minimal clinical ly important difference ( MCID ) falls . In three studies in which instruments measuring  dyspnea , fatigue , and emotional function in patients with chronic heart and lung disease were applied the MCID was represented by mean change in score of approximately 0.5 per item , when responses were presented on a seven point Likert scale . Furthermore , we have established ranges for changes in question naire scores that correspond to moderate and large changes in the domains of interest . This information will be useful in interpreting question naire scores , both in individuals and in groups of patients participating in controlled trials , and in the planning of new trials
The evidence supports the WPAI as having test-retest reliability ( reproducibility ) over time ; convergent validity , as indicated by moderate correlations with measures of quality of life and moderate-to-strong correlations with measures of disease activity ; known-groups validity , as indicated by differences in WPAI scores between patients with active and inactive disease ; ability ( sensitivity ) to detect change , as indicated by substantial improvement in scores for patients who achieve remission , accompanied by substantial worsening of scores for patients who relapse ; and , responsiveness to treatment , with improvements in scores following treatments that reduce disease activity .
Patients with ulcerative colitis , a type of inflammatory bowel disease , report negative impacts of disease symptoms on work-related outcomes , including absenteeism and presenteeism .
As a way to better underst and the impact of this disease and its treatment on work-related outcomes , the current review examines the use of the Work Productivity and Activity Impairment Question naire ( WPAI ) , a patient-reported outcomes measure of absenteeism , presenteeism , and impairment in other activities , in studies of patients with ulcerative colitis .
This review assesses the measurement properties of the WPAI in this patient population : its reliability , construct validity , ability to detect change , and responsiveness to effective treatments .