ade qu ate ▁in cent ive ▁to ▁rest rain ▁health ▁care ▁prices ▁or ▁over use . ▁This ▁drives ▁pay ers , ▁such ▁as ▁national ▁health ▁ins urance ▁systems ▁or ▁the ▁U . S . ▁Cent ers ▁for ▁Medic are ▁and ▁Med ica id ▁Services , ▁to ▁focus ▁on ▁medical ▁necessity ▁as ▁a ▁condition ▁for ▁payment . ▁However , ▁the ▁threshold ▁between ▁necessity ▁and ▁lack ▁there of ▁can ▁often ▁be ▁subject ive . ▁ ▁O vert re at ment , ▁in ▁the ▁strict ▁sense , ▁may ▁refer ▁to ▁unnecessary ▁medical ▁inter vent ions , ▁including ▁treatment ▁of ▁a ▁self - limited ▁condition ▁( over di agn osis ) ▁or ▁to ▁extensive ▁treatment ▁for ▁a ▁condition ▁that ▁requires ▁only ▁limited ▁treatment . ▁ ▁It ▁is ▁econom ically ▁linked ▁with ▁over med ical ization . ▁ ▁Definition ▁ ▁A ▁for er un ner ▁of ▁the ▁term ▁was ▁what ▁Jack ▁W enn berg ▁called ▁unw arr anted ▁variation , ▁different ▁rates ▁of ▁treat ments ▁based ▁upon ▁where ▁people ▁lived , ▁not ▁clin ical ▁r ationale . ▁He ▁had ▁discovered ▁that ▁in ▁studies ▁that ▁began ▁in ▁ 1 9 6 7 ▁and ▁were ▁published ▁in ▁the ▁ 1 9 7 0 s ▁and ▁the ▁ 1 9 8 0 s : ▁" The ▁basic ▁prem ise ▁- ▁that ▁medicine ▁was ▁driven ▁by ▁science ▁and ▁by ▁phys icians ▁capable ▁of ▁making ▁clin ical ▁dec isions ▁based ▁on ▁well - est ab lished ▁fact ▁and ▁theory ▁- ▁was ▁simply ▁in compatible ▁with ▁the ▁data ▁we ▁saw . ▁It ▁was ▁immediately