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 .
Microvascular decompression for classic trigeminal neuralgia: determination of minimum clinically important difference in pain improvement for patient reported outcomes.
BACKGROUND Outcomes studies use patient-reported outcome ( PRO ) measurements to assess treatment effectiveness , but can lack direct clinical meaning . Minimum clinical ly important difference ( MCID ) calculation provides a point estimate of the critical threshold needed to achieve clinical ly relevant treatment effectiveness . MCID remains uninvestigated for microvascular decompression ( MVD ) , a common surgical procedure for trigeminal neuralgia . OBJECTIVE We aim ed to determine MCID for the most commonly used PRO measures of pain after MVD : Visual Analog Scale ( VAS ) and Barrow Neurological Institute Pain Scale ( BNI-PS ) . METHODS Sixty consecutive patients with classic trigeminal neuralgia who decided to undergo MVD by a single surgeon were prospect ively assessed with  VAS  and BNI-PS preoperatively and 2 years postoperatively . Three anchors were used to assign each patient 's outcome . We then used 3 well-established , anchor-based methods to calculate MCID . RESULTS Patients experienced significant improvement in both VAS ( 9.9 vs. 2.0 , P < .001 ) and BNI-PS ( 5.0 vs. 1.9 , P < .001 ) after MVD . The area under the receiver-operating characteristic curve was greater for BNI-PS than for VAS for all 3 anchors , indicating that BNI-PS is probably better suited for calculating MCID . The 3 MCID calculation methods generated a range of  MCID values for each of the PROs ( VAS : 1.40 - 8.87 , BNI-PS : 0.95 - 3.26 ) . CONCLUSION MVD-specific MCID is highly variable based on calculation technique . Some of these calculations appear to either overestimate or underestimate the patients ' preoperative expectations . When the different MCID methods are averaged , the results are clinical ly appropriate and consistent with preoperative expectations . The average MCID for VAS is 6.25 and for BNI-PS is 2.44
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 .