We observed a lack of consistency in the application of methods for computing MID or MCID for generic and disease-specific HRQoL measures .
The anchor-based method yields conservative estimates of MID or MCID , compared to the distribution-based method .
OBJECTIVES The objective of the study was to assess the usability of minimal important difference ( MID ) and minimal clinical ly important difference ( MCID ) for measuring meaningful changes in disease-specific and generic health-related quality -of-life ( HRQoL ) outcomes in patient-centered care .
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
We observed a lack of consistency in the application of methods for computing MID or MCID for generic and disease-specific HRQoL measures .
The anchor-based method yields conservative estimates of MID or MCID , compared to the distribution-based method .
OBJECTIVES The objective of the study was to assess the usability of minimal important difference ( MID ) and minimal clinical ly important difference ( MCID ) for measuring meaningful changes in disease-specific and generic health-related quality -of-life ( HRQoL ) outcomes in patient-centered care .