To Screen or Not To Screen? Primary care physicians routinely face the complicated decision of when to offer preventive services and to whom. Some preventive services, like screening tests, may not help everyone and may even harm some. Conflicting guidelines complicate decision-making further.

"I'm a primary care physician," says Dr. Richard Hoffman, professor at the University of New Mexico School of Medicine and staff physician at the Albuquerque VA Medical Center. "We're the ones to actually implement screening guidelines."

In a recently published article in the "Annals of Family Medicine," Hoffman and his co-authors suggest using trustworthy clinical practice guidelines and decision aids to sort through screening decisions. They offer the example of prostate cancer screening.

The United States Preventive Services Task Force gave prostate cancer screening a D rating in their May 2012 recommendations. The Task Force consists of independent non-Federal primary care providers who are experts in prevention and evidence-based medicine. The D rating means that the Task Force recommends against prostate cancer screening because its harms, like over diagnosis and surgical complications, outweigh its benefits. Among other things, they report that while 5 in 1,000 men who didn't have the screening died of prostate cancer, between 4 and 5 in 1,000 men who got the screening died of prostate cancer. These data suggest that the screening prevented few, if any, deaths.

But the American Urological Association released guidelines developed by its multidisciplinary panel of specialists in 2009. "Urologists see men dying from prostate cancer," says Hoffman. "It's a terrible death." The AUA guidelines recommend prostate cancer screening for all men 40 years and older.

So which recommendation should primary care physicians follow? Deciding in favor of one recommendation over the other possibly forces them into an untenable legal situation. "Too much prevention can do more harm and expend resources we don't have," said Hoffman. Providing the preventive services strongly recommended by the Task Force can cost physicians over seven hours a day according to a study published in the "American Journal of Public Health" in 2003. "When you add that onto taking care of people with chronic and acute illnesses," added Hoffman, "you have to draw the line somewhere and be realistic. That's why we think there needs to be a balance."

Then there's section 2713 of the Patient Protection and Affordable Care Act of 2010 that describes mandatory coverage for health services. It specifies "evidence-based items or services that have in effect a rating of ‘A' or ‘B' in the current recommendations of the United States Preventive Services Task Force." The Affordable Care Act doesn't cover prostate cancer screening. The Act also forges a link between the Task Force and financial and political interests, a link that Congress didn't make in 1984 when it created the Task Force.

Primary care physicians need to realistically balance these myriad considerations while making the tradeoff between over diagnosis and catching disease in its early, more treatable stages. Hoffman and his co-authors suggest the use of decision aids and a standardized process to develop guidelines.

Trustworthy guidelines help primary care physicians decide who to offer screening to and when. In their article, Hoffman and his co-authors propose standards to develop trustworthy clinical practice guidelines so that physicians can plan their conversations about the benefits and risks of preventive services with their patients. "The guideline development process should be free of conflicts of interest and focus on the evidence," he explains.

Decision aids help physicians to help patients to make informed decisions. "If a man is really worried about dying from prostate cancer and wants to get screened and he understands the risks," Hoffman says, "that's fine. We want to preserve the patient's voice in their own healthcare."