Using life expectancy and prognosis to support shared decision-making

- Kenny Lin, MD, MPH

Due to competing causes of mortality, the benefits of most screening tests decline with increasing age; for example, screening for breast and colorectal cancers is not recommended in persons with a life expectancy of less than 10 years. However, estimating an individual patient's life expectancy and incorporating that estimate into shared decision-making with patients is challenging. A 2014 U.S. population-based survey found that 31% to 55% of participants with a greater than 75% risk of death in the next 9 years were still receiving breast, colorectal, or prostate cancer screenings.

There are multiple reasons why physicians provide so many unnecessary and potentially harmful screening tests to older persons with limited life expectancies. In an editorial in the September 1 issue of AFP, Dr. Emma Wallace and Norah Murphy observed that "barriers to discussing life expectancy include uncertainty in prognostic estimates, limited time to broach this sensitive topic, and concerns about upsetting the patient or getting negative reactions."

A systematic review of the prognostic value of the "Surprise Question" approach (which asks clinicians, "would you be surprised if this patient died in the next 12 months?") found that the answer has varying degrees of accuracy at identifying patients in their last year of life. The QMortality tool, in contrast, generates a more precise estimate of one-year mortality in persons age 65 to 99 years utilizing multiple clinical and demographic variables, and was found to have good predictive accuracy in 500,000 family practice patients in England.

Some patients may feel uncomfortable about stopping nonbeneficial screening tests even if they are objectively unlikely to benefit from them. In a mailed survey of patients age 50 years or older in the Veterans Affairs health system, nearly 30 percent reported being "not at all comfortable" with discontinuing screening colonoscopy in a hypothetical patient scenario where a colorectal cancer-specific risk calculator predicted a low likelihood of benefit. To help family physicians sensitively incorporate prognostic information into screening discussions, the University of California San Francisco's ePrognosis website provides risk calculators and video examples demonstrating key patient communication skills.