In the early 1990s, guidelines on screening for prostate cancer were in sharp conflict. The American Urological Association, American Cancer Society, and other groups advocated screening, while conservative organizations such as the U.S. Preventive Services Task Force and the Canadian Task Force on the Periodic Health Examination maintained that the evidence was insufficient to make a recommendation.

In the decade that followed, the once-embattled organizations converged around the notion of shared decision making. Proponents of screening came to recognize that patients were entitled to know about the scientific uncertainty surrounding the benefits of screening and the potential harms induced by false-positive results and treatment complications. Whether treatments are necessary or effective remains unclear as described in the review by Bhatnagar and Kaplan¹ in this issue of American Family Physician. Critics of screening came to recognize that the absence of evidence of effectiveness did not prove ineffectiveness and that patients had a right to know about the possibility of benefits.

In 1997, the American College of Physicians² recommended that the physician “describe the potential benefits and known harms of [prostate] screening…, listen to the patient's concerns, and then individualize the decision to screen.”

In 1998, the American Academy of Family Physicians³ advised physicians to “counsel [men] regarding the known risks and uncertain benefits of screening for prostate cancer.”

In 2000, the American Urological Association⁴ stated that “the decision to use prostate-specific antigen (PSA) testing for the early detection of prostate cancer should be individualized. Patients should be informed of the known risks and the potential benefits.”

In 2001, the American Cancer Society⁵ stated that “prior to testing, men should have an opportunity to learn about the benefits and limitations of testing for early prostate cancer detection and treatment.”

In 2002, the U.S. Preventive Services Task Force⁶ concluded that “clinicians should not order the PSA test without first discussing with the patient the potential but uncertain benefits and the possible harms….”

Despite the consensus on the appropriateness of shared decision making, there is limited evidence about the frequency with which it occurs in practice. Audio recordings of clinical encounters conducted a decade ago revealed that patients received complete information on 9 percent of decisions.⁷ In a survey⁸ published in 2001, just 17 percent of physicians reported that they would decide whether to order a PSA test based on patient preferences. Only two thirds of men who are screened even know that they have been tested.⁹ These data suggest that little shared decision making is occurring.

Physicians encounter a variety of disincentives to engaging in shared decision making. There is limited time and reimbursement for long discussions. Many physicians have inadequate support to review the benefits, risks, and scientific uncertainties surrounding options, and some question whether it is the best way to make decisions.¹⁰ Many patients have difficulty processing the information. Physicians and patients who believe intuitively in the benefits of screening find little motivation to engage in shared decision making. Many patients arrive at the encounter with the expectation that they will be tested or that the physician will recommend which tests are appropriate.

Perhaps the starkest disincentive to shared decision making is medicolegal concerns. Physicians worry that not performing screening, regardless of a patient's preference, puts them at risk if the patient develops invasive prostate cancer in the future. This dilemma was expressed poignantly in an essay by Merenstein,¹¹ a family physician whose residency program was sued because it had taught him to engage in shared decision making. He described the trauma of the experience, which caused him to see patients as possible plaintiffs: “I no longer discussed the risks and benefits of prostate cancer screening. I ordered more laboratory and radiologic tests and simply referred more.”¹¹

From the physician's perspective, eschewing shared decision making brings potential benefits: it saves time, obviates the reimbursement and logistic challenges of shared decision making, and minimizes liability for failure to screen. Abandoning shared decision making also has a downside. It conflicts with the professional ethos to “do the right thing” and support informed choice. It introduces medicolegal vulnerabilities if the patient sues for complications that result from screening. The effectiveness of shared decision making, much like prostate cancer screening, is uncertain. Scientific evidence is inadequate to determine whether benefits outweigh harms for patients or physicians.

Circumstances that call for shared decision making in patients' choices about screening—an uncertain balance between benefits and harms that is best determined by personal preferences—also apply to the physician deciding to refrain from shared decision making. Just as the patient must decide, based on personal values, whether the benefits outweigh the risks, the physician must decide whether what is gained by circumventing the challenges of shared decision making is offset by its harms to the patient and physician. It is a personal choice that only conscience, not guidelines, can dictate.