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 .
Usefulness of minimum clinically important difference for assessing patients with subaxial degenerative cervical spine disease: statistical versus substantial clinical benefit
Background The measurement of the therapeutic outcome of cervical spine surgeries commonly relies on four main patient reported outcomes ( PROs ) : Neck Disability Index ( NDI ) , Visual Analog Scale ( VAS ) for pain , and Short Form-36 ( SF-36 ) Physical ( PCS ) and Mental ( MCS ) Component Summary . However , the clinical impact of such scores and how they could effectively measure therapeutic efficacy remains unclear . In this context , the concept of minimum clinical ly important difference ( MCID ) is developing into the st and ard by which to evaluate treatments , patient satisfaction and cost-effectiveness . Methods Eighty-eight consecutive patients undergoing surgery for subaxial degenerative cervical spine disease were selected from a prospect i ve blinded data base . PROs ( NDI , PCS , MCS and VAS ) were collected preoperatively , and together with blinded Surgeon Ratings ( SR ) at 3 months and 6 months post-surgery . Four anchor-based approaches were used to calculate different MCIDs . Three anchors ( VAS , HTI ( Health Transition Item of the SF-36 ) and SR ) were used to evaluate surgery outcome . The best clinical ly and statistically relevant MCID was chosen . Results On average , all patients presented with a statistically significant improvement ( p < 0.001 ) postoperatively for NDI ( 27.42 to 19.42 ) , PCS ( 33.02 to 42.03 ) , MCS ( 44 to 50.74 ) and VAS ( 2.85 to 1.93 ) . The four MCID anchor-based approaches yielded a range of values for each PRO : 2.23–16.59 for PCS , 0.11–16.27 for MCS and 2.72–12.08 for NDI . When compared to the VAS and HTI anchors , the area under the ROC curve was greater for SR . This finding suggests that SR may be a more reliable anchor for MCID calculation . Conclusion The MDC ( minimum detectable change ) approach together with the SR anchor appears to be the most appropriate MCID method . It offers the greatest area under the ROC curve ( threshold above the 95 % CI ) , and the choice of the anchor did not significantly affect this result . MCID values for this data set were 5.6 for PCS , 5.12 for MCS and 2.41 for NDI
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 .