Accountable Care Organizations in California: Market Forces at Work?

Area of Science:

• Health Services Research
• Health Economics
• Healthcare Management

Background:

• Accountable Care Organizations (ACOs) are an innovative healthcare delivery model focused on care coordination.
• ACOs aim to reduce costs and improve resource utilization.
• Concerns exist regarding the potential for ACOs to increase provider market power.

Purpose of the Study:

• To examine market-level competition factors influencing ACO participation and the number of ACOs.
• To understand how managed care, hospital concentration, and physician market power affect ACOs.

Main Methods:

• Analysis of data from California.
• Examination of the relationship between market competition factors and ACO entry/enrollment.

Main Results:

• Higher preexisting managed care levels correlate with increased ACO entry and enrollment.
• Increased hospital concentration is associated with fewer ACOs and lower enrollment.
• Concentrated physician markets show a smaller share of individuals in commercial ACOs but a higher number of commercial ACO organizations, implying smaller ACOs.

Conclusions:

• Market competition dynamics significantly influence ACO development and structure.
• Managed care environments foster ACO growth, while hospital consolidation may hinder it.
• Physician market power affects ACO size and distribution, potentially leading to market fragmentation.