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 .
Percutaneous stereotactic radiofrequency lesioning for trigeminal neuralgia: determination of minimum clinically important difference in pain improvement for patient-reported outcomes.
BACKGROUND The Visual Analog Scale ( VAS ) and the Barrow Neurological Institute Pain Scale ( BNI-PS ) are 2 patient-reported outcome ( PRO ) tools frequently used to rate pain from trigeminal neuralgia ( TN ) . Outcomes studies often use these patient-reported outcomes to assess treatment effectiveness , but it is unknown exactly what degree of change in the numerical scores constitutes the minimum clinical ly important difference ( MCID ) . MCID remains uninvestigated for percutaneous stereotactic radiofrequency lesioning ( RFL ) , a common surgical procedure for TN . OBJECTIVE To determine MCID values for the VAS and BNI-PS in patients undergoing RFL . METHODS Forty-three consecutive patients with TN who underwent RFL by a single surgeon were prospect ively assessed with the VAS and BNI-PS preoperatively and 3 years postoperatively . Three anchors were used to assign each patient 's outcome : satisfaction , willingness to have the surgery again , and Health Transition Index . We then used 3 well-established , anchor-based methods to calculate MCID : average change , minimum detectable change , and change difference . RESULTS Patients experienced substantial improvement in both VAS ( 9.81 vs 3.35 ; P < .001 ) and BNI-PS ( 4.95 vs 2.44 ; P < .001 ) after RFL . The 3 MCID calculation methods generated a range of MCID values for each of the PROs ( VAS , 4.13 - 8.20 ; BNI-PS , 1.03 - 3.30 ) . The area under the receiver-operating characteristic curve was greater for BNI-PS compared with VAS for all 3 anchors , indicating that BNI-PS is probably better suited for calculating MCID . CONCLUSION RFL-specific MCID is variable on the basis of the calculation technique . With the use of the minimum detectable change calculation method with the Health Transition Index anchor , the minimum clinical ly important difference is 4.49 for VAS and 1.16 for BNI-PS after RFL for TN . ABBREVIATIONS AUC , area under the receiver-operating characteristic curveBNI-PS , Barrow Neurological Institute Pain ScaleHTI , Health Transition IndexMCID , minimum clinical ly important differenceMDC , minimum detectable changePRO , patient-reported outcome RFL , percutaneous stereotactic radiofrequency lesioningTN , trigeminal neuralgiaVAS , Visual Analog Scale
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 .