Absolute MCID was strongly associated with baseline pain , explaining approximately two-thirds of the variation , and to a lesser degree with the operational definition of minimum pain relief and clinical condition .
MCID  for chronic pain relief vary considerably .
Baseline pain is strongly associated with absolute , but not relative , measures .
To a much lesser degree , MCID is also influenced by the operational definition of relevant pain relief and possibly by clinical condition .
BACKGROUND The minimum clinical ly important difference ( MCID ) is used to interpret the relevance of treatment effects , e.g. , when developing clinical guidelines , evaluating trial results or planning sample sizes .
There is currently no agreement on an appropriate MCID in chronic pain and little is known about which context ual factors cause variation .
METHODS This is a systematic review .
Should study subjects see their previous responses: data from a randomized control trial.
To test the relative merits of administering question naires with previous responses available ( the informed condition ) or unavailable ( the blind condition ) , we administered blind and informed versions of a quality of life question naire ( the Chronic Respiratory Disease Question naire , or CRQ ) in a r and omized , double-blind trial of bronchodilators in chronic airflow limitation . The responsiveness of the two methods , as reflected in the p-values associated with salbutamol and theophylline effects were comparable for three of the four dimensions of the CRQ . The data suggested possible increased responsiveness of the informed method for the emotional function dimension of the question naire . Changes in the informed CRQ dyspnea and fatigue dimensions showed stronger correlations with changes in spirometry , 6 minute walk distance , and rating of dyspnea after the walk test than did blind administration . Further , changes in all four CRQ dimensions showed stronger correlations with corresponding global ratings using the informed question naire . These results suggest that by letting study subjects see their previous responses the validity of subjective measures of health status in clinical trials can be improved
Absolute MCID was strongly associated with baseline pain , explaining approximately two-thirds of the variation , and to a lesser degree with the operational definition of minimum pain relief and clinical condition .
MCID  for chronic pain relief vary considerably .
Baseline pain is strongly associated with absolute , but not relative , measures .
To a much lesser degree , MCID is also influenced by the operational definition of relevant pain relief and possibly by clinical condition .
BACKGROUND The minimum clinical ly important difference ( MCID ) is used to interpret the relevance of treatment effects , e.g. , when developing clinical guidelines , evaluating trial results or planning sample sizes .
There is currently no agreement on an appropriate MCID in chronic pain and little is known about which context ual factors cause variation .
METHODS This is a systematic review .