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 .
Postsurgical pain outcome assessment
& NA ; Reliable and valid measures of pain are essential for conducting clinical trials of pain treatments . Perhaps the most important aspect of a pain measure 's validity is its sensitivity , or ability to detect changes in pain over time and due to treatment . Several factors may affect a measure 's sensitivity , including the complexity of the rating task for the measure , the number of pain intensity levels assessed by the measure , the dimension of pain assessed ( e.g. pain intensity vs. pain relief ) , and the number of individual ratings ( e.g. single rating vs. composite score ) used to create the measure . The purpose of this study was to compare the relative sensitivity of three measures of outcome and a composite made up of all three measures for detecting analgesic effects in two sample s of persons participating in a r and omized controlled trial . One hundred and twenty‐three patients who had undergone knee surgery and 124 women who had undergone a laparotomy were given one of three medications in the day after their surgery : morphine , ketorolac , or placebo . Two measures of pain intensity ( a visual analog scale ( VAS ) and a 4‐point verbal rating scale ( VRS ) ) were administered at baseline , and these measures plus a 5‐point VRS of pain relief were administered at 16 additional time points up to 24 h following surgery . As predicted , we found variability in the sensitivity of the outcome measures used in these studies , with the 4‐point VRS showing less sensitivity than the VAS or relief ratings . However , contrary to our prediction , a composite measure of outcome made up of all three measures was not consistently superior to the individual measures for detecting treatment effects . Finally , we found that pain relief ratings were related to , but also distinct from , change in pain intensity as measured by changes in pain intensity ratings from baseline to each postmedication assessment point . These findings have important implication s for the assessment of pain in clinical trials
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 .