After WWII, what led insurers to place limitations on outpatient medical care?

The limitation that insurers placed on outpatient medical care after WWII was primarily driven by the challenge of managing indefinite treatment periods combined with subjective evaluations of care necessity. This scenario created a situation where it was difficult for insurers to effectively control costs and assess the appropriateness of the care being provided. The variability in treatment lengths and the lack of standardized measures to evaluate treatment effectiveness posed significant risks for insurers.

Long, open-ended outpatient treatments could lead to escalating costs without a clear endpoint or measurable outcomes, making it tricky for insurers to budget and manage their claims. By implementing limitations, insurers sought to establish clearer criteria around outpatient care, enhancing their ability to predict costs and maintain financial stability within their risk pools. Thus, while other factors also influenced policy decisions, the subjective nature of outpatient care evaluation was a particularly compelling reason for insurers to impose restrictions in that era.