We're only a few short years into hospitals' movement toward treating the health of patient populations, but already some key challenges and lessons learned are starting to emerge.

A new report from the American Hospital Association and consulting firm Leavitt Partners, released last week, takes a closer look at some of the high-level revelations across the field. Titled "The Impact of Accountable Care: Hospital Involvement with Accountable Care Organizations," the easily digestible guide is broken into five sections, including case studies from three different types of hospitals working in ACOs, and includes a breakdown of different types of payment models.

The guide is one in a series produced by Leavitt exploring the ACO transition from different perspectives — payer, provider, consumer and now hospital. One key takeaway for hospital leaders is that organizations of all shapes and sizes are struggling with the shift to value-based care, but the savvy ones are embracing the chance to reinvent themselves, says co-author and Leavitt Senior Analyst Tom Merrill.

"Even the most advanced organizations are coming up against some real challenges, but an equal variety of organizations are seeing a lot of opportunity here," he says. "The ACO movement for them presents one of the first opportunities to really practice care the way they've always wanted to, aligning with physicians, for example, which also presents challenges. Not every physician group wants to align with the hospital."

The guide details some of those common hurdles hospitals face as they move toward population health. Along with the difficulty of physician alignment, typical barriers include seeking the proper mix of payers, figuring out how to distribute shared savings, pegging the right doc leadership and integrating with physician practices.

Retooling a hospital's culture toward this new mindset is also a big challenge, according to the guide. The ACO model doesn't fit squarely into how hospitals have operated for years, and that's why it's critical to have strong leadership in place to drive continuous quality improvement, with incentives that avoid pitting departments against one another, as well as sufficient investment and commitment to the transition.

Momentum seems to be building in the population health movement, and the ACO is one model to help shepherd hospitals into this new world, says Heather Jorna, another co-author of the guide and vice president of health care innovation at the AHA.

"There is definitely a movement toward population health management, and this is one of the models that's emerging," she says. "And so, in order to successfully manage a population, there's going to need to be pretty strong leadership, and a willingness to work with physicians and data to understand your population. This guide is kind of a primer in terms of some of the considerations, and there are some promising results."