Firstly, do you understand what "managed care" is?
Doctors are forced to treat their patients along 'managed care' guidelines as set down by the health insurance companies, rather than being free to manage each individual patient according to their own medical wisdom and discretion. Treatment of any patient can have complications, and sometimes, can go terribly wrong. For example, a person being discharged from hospital to free up a bed for another patient, and the person dying within hours of being at home. This might then be regarded with hindsight as caused by too early a discharge forced by the need to follow 'managed care' guidelines (as no further hospital fees would be paid after that date by the insurance company). Such 'horror stories', reported by doctors and publicized in the media, damage the credibility of, and public's faith in, 'managed care' practices. Each of these 'horror stories' is one of the thousand and more anecdotes of medical 'mismanagement' that kills off faith in 'managed care', for the doctors and public alike.