Doctors giving regular checkups will get the most bang for their buck if they advise adults to quit smoking, convince teens to never start, and keep children up to date with immunizations, according to an influential report released Monday by the Bloomington-based HealthPartners Institute.

The research findings, sponsored in part by the U.S. Centers for Disease Control and Prevention, could influence how doctors across the country conduct thousands of regular patient visits each year.

Comparing 28 recommended preventive services, HealthPartners researchers found that tobacco counseling and pediatric immunizations outranked the others in cost-effectiveness and the potential to save lives.

While all the preventive services are valuable, the reality is that doctors can't do them all in a standard 15-minute office visit, said Dr. George Isham, a senior fellow with the institute.

"In an imperfect world, we don't always get the chance to do everything we should. It's a matter of attending to those things that are most important first," Isham said.

National health care leaders encouraged doctors to use the findings to set their own priorities; a prior study found that doctors would spend 7.4 hours per day if they tried to provide all recommended preventive services to all patients.

The study found a particularly strong impact if 90 percent of youth received tobacco prevention counseling — a huge increase from the 20 percent that actually receive it today. "Tobacco use has certainly come down over time, both among adults and youth," said Michael Maciosek, the study's lead author. "Nevertheless, it remains a huge problem compared to other health threats."

HealthPartners' first ranking of preventive services received wide notice when it came out in 2006 — at a time when rising deductibles and copays made patients more sensitive to medical bills and which services they were paying for out of pocket.

Today, preventive services are fully covered by insurers — a requirement of the 2010 Affordable Care Act. But pledges by President-elect Donald Trump and Republican lawmakers to repeal the act could make patients more sensitive to costs again.

"These are all valuable kinds of things, but this research tells us some things are more valuable than others," said Isham, who wrote an editorial that accompanied the research in the Annals of Family Medicine.

Even with preventive services fully covered, the report provides important information to doctors and to health plans in terms of the incentives they provide to doctors, Maciosek said, especially when doctors face time constraints.

For many of the preventive services, the researchers used computer modeling to predict the consequence if they were never offered vs. the costs and years of life saved if they were always offered to patients. (The models accounted for the fact that some patients would refuse services.)

The ranking has limitations, including that it gives equal weight to cost effectiveness and clinical benefit. For example, the ranking found obesity counseling to be among the least cost effective — dropping it in the overall ranking. But it is one of the most effective services in preventing costly diseases over time, the study found.

"The rankings should help guide us as a nation," said Dr. Eduardo Sanchez, chief medical officer for prevention at the American Heart Association. "It can be hard to know where to begin with competing priorities."