As a family physician, preventive care is one of the things I love talking to patients about but I find it tends to be misunderstood by most people. Many people assume that more screening automatically means better health and get frustrated when their annual “exam” is nothing more than their provider looking at their blood pressure and checking if they’ve completed their colonoscopy.
However, preventive care works best when a test meaningfully changes outcomes that matter: living longer, living better, and most importantly avoiding serious harm. Not every screening test meets that standard.
Cancer screening is the clearest example. Some screenings clearly reduce deaths from the target cancer, but their effect on overall lifespan is smaller than most people expect. A large 2023 analysis in JAMA (Journal of the American Medical Association) Internal Medicine found that for five of six common cancer screenings studied, there was no clear increase in all‑cause mortality, even though some individuals do benefit substantially [1]. This doesn’t mean screening is useless—it means benefits are modest, unevenly distributed, and must be weighed against real harms like false positives, invasive follow‑up testing, overdiagnosis, and treatment complications.
That balance matters. It’s the reason that we no longer recommend prostate exams for prostate cancer screening. Screening can prevent cancer or catch it early in a subset of patients who then go on to live longer. Others may undergo biopsies, surgery, or radiation for cancers that would never have affected their health. These unnecessary treatments have real costs, both financially as well as functional effects on their bodies. In the case of prostate cancer, is the possibility of having to wear adult diapers after treatment, worth it when many more men die WITH prostate cancer than OF prostate cancer. That can be a hard question to answer.
Contrast that with cardiovascular prevention. Managing blood pressure, avoiding tobacco, adequate sleep and weight maintenance, and maintaining physical activity consistently outperform most screening tests in terms of lives saved. The CDC estimates that 30–50% of cancers are preventable through risk‑factor modification, vaccination, and appropriate screening—not screening alone [2].
Some commonly requested tests illustrate where preventive care can miss the mark. For example, routine urine dipstick screening for kidney disease in low‑risk adults, produces high false‑positive rates, drives unnecessary follow‑up, and has no strong evidence of improving outcomes, while adding cost and anxiety for patients [3]. That’s not prevention—it’s noise in the medical system.
Emerging areas like genomic screening are promising but still evolving. Large health‑system programs show that actionable genetic findings can change care for a small number of patients, but broad population use remains limited and is not yet routine for primary care [4].
The most effective preventive care I deliver is personalized. It considers age, risk factors, family history, and—critically—what outcomes a patient values. Screening is a tool, not a virtue.
Good prevention isn’t about doing everything. It’s about doing the right things, for the right people, at the right time; and being honest about what the evidence actually shows. That’s what primary care is for, explaining the evidence to regular people in lay-men’s terms so we can make an informed decision together.
Sources:
1. https://jamanetwork.com/
2. https://www.cdc.gov/pcd/
3. http://cjasn.asnjournals.org/
4. https://jamanetwork.com/
