=====Minimum cost effective difference=====
Minimum cost effective difference (MCED) serves as the smallest [[improvement]] in an [[outcome]] instrument that is associated with a cost-effective response to surgery. With the use of cost-effective anchor of < $50 000/[[quality-adjusted life year]] (QALY), MCED after [[transforaminal lumbar interbody fusion]] was 4 points for [[visual analog scale]] for [[low back pain]], 3 points for visual analog scale for [[leg]] [[pain]], 22 points for [[Oswestry Disability Index]], and 0.31 QALYs for [[EuroQol 5D]]
((Parker SL, McGirt MJ. Determination of the minimum improvement in pain,
disability, and health state associated with cost-effectiveness: introduction of 
the concept of minimum cost-effective difference. Neurosurgery. 2015 Mar;76 Suppl
1:S64-70. doi: 10.1227/01.neu.0000462079.96571.dc. PubMed PMID: 25692370.
))