Hundreds of health policy studies were released this summer, on everything from California’s integrated delivery systems to how teenagers’ friends influence their health decisions. But research studies sometimes get short shrift in a world where political back-and-forth dominates the headlines.

In an effort to spotlight some of the more influential research, “Road to Reform” is back with the second annual Sidneys. (As detailed last year, the column owes its inspiration to New York Times columnist David Brooks, as well as California’s own Sidney Garfield.) Here are five of the most important, and interesting, studies from this summer’s journals and reviews.

For the second straight year, “Road to Reform” awards the first Sidney to a study with direct implications for the ongoing health reform debate. Writing in the New England Journal of Medicine, researchers found that expanding Medicaid coverage was linked to a 6.1% decline in deaths. There’s an important difference between this new research and a similar study that got attention in 2011; last year’s effort to track the impact of Oregon’s Medicaid expansion relied on a randomized control trial, which may have produced more “pure” data, while this year’s study contrasts state-level expansions. But it’s more evidence that government health insurance appears to offer quality-of-life benefits, as states wrestle with whether to significantly expand Medicaid coverage after the Supreme Court’s ruling on the Affordable Care Act placed the decision in their hands.

Why have U.S. health costs been slowing down? Most observers would say it’s an effect of the recession, but Sidney No. 2 goes to an Altarum Institute study in NEJM that suggests the trend predates the 2008 economic downturn — that “the bend in the spending-growth curve began in mid-2005, continued through the recession, and seems to be holding.” The researchers still aren’t sure exactly why the slowdown began then, or whether the trend will continue as the ACA’s provisions are implemented.

More patients are wrestling with expensive, chronic illness, which adds cost and coordination challenges to the health system. Our third Sidney goes to a study in Health Affairs that drilled down on one major problem: medication adherence. Examining a sample of diabetes patients, researchers found that improving adherence to diabetes medication was linked with a 13% reduction in hospitalization and emergency department visits; they also projected that better adherence could reduce national health spending by almost $5 billion. “Following through on doctor’s orders” may seem like a simple prescription for better health care quality and less spending, but it’s clearly effective.

Is health provider consolidation ultimately a positive or negative for patients? A Sidney-winning review from the Robert Wood Johnson Foundation suggests that the continued trend may bode poorly for the nation’s health system. Researchers found that there’s evidence that competition doesn’t just cut providers’ prices, but boosts quality, too. It’s an important issue to watch as more hospitals attempt to band together or acquire physician practices — and the Federal Trade Commission continues to step in and try to stop them.

A Sidney may not be as sought after as an Olympic gold medal — yet — but today’s final award goes to a series of studies on physical activity in The Lancet that were loosely tied to this summer’s games. And the findings should scare some policymakers into action: Once considered just a U.S. problem, voluntary physical inactivity has spread across the globe and now is responsible for more deaths each year (about 5.3 million) than cigarette smoking (about 5.1 million), Harvard University researchers found. Roughly 31% of adults around the world are considered inactive, according to another study.

That’s it for this year’s Sidneys. See an interesting study that we missed? Pass along your suggestions — we’re always looking for good, wonky reads.