A 53-year-old woman on Medicaid in Washington state who has never had a mammogram elects to get one in return for a $15 gift card.

A 35-year-old woman in Florida chooses to get her first mammogram because her insurer, Aetna, offers a $50 payroll check.

In Iowa, a 46-year-old woman who has been getting mammograms every other year opts to get them annually because Wellmark Blue Cross Blue Shield will pay her $50 to do so.

All three of these women have average risk profiles, and none have family members with breast cancer. Who made the right choice?

It’s a trick question. The real question is whether employers and health plans should really be offering incentives to women to get frequent mammograms.

Women hear all the time that “mammography saves lives,” a message the American College of Radiology and various breast cancer charities have been repeating for years. But the advice does not apply to all women — at least it shouldn’t.

The U.S. Preventive Services Task Force recommends that women at average risk for breast cancer begin getting regular mammograms at age 50, and then every other year until age 74. The American Cancer Society recommends yearly mammography from ages 45 to 54, then screenings every other year afterward.

Other groups hew to still other positions. The diversity of opinions is entirely understandable. The data is anything but clear, and that raises tough questions about whether incentives to get screened are appropriate.

We do know that regular screening reduces the chances of dying from breast cancer, but the reduction seems to be small. For all deaths averted, according to the task force, at least twice as many women will have received entirely unnecessary treatment and the anxiety that comes with it.

In truth, estimates of the benefits and harms of screening are all over the map; researchers themselves do not agree on the facts.

In choosing among competing guidelines, women are being asked to strike a delicate balance. The trade-offs are complex and dependent on personal values. Employer and health plan incentives suggest that mammograms are inherently worthwhile and risk glossing over these nuances.

This complicated weighing of pros and cons should not be sidestepped by simply paying women to have mammograms. Instead, employers and health plans should offer incentives that reward the use of evidence-based decision aids.

In short: Don’t pay women to get mammograms — pay them to use a tool to decide whether they should get mammograms. Such a tool might well have suggested that two of our hypothetical women reconsider the choice to be screened: the two younger ones.

Financial incentives for getting mammograms are doubtless well intended. But it would be far more ethical to use incentives to encourage women to make decisions informed by evidence.

Harald Schmidt is an assistant professor of medical ethics and health policy at the University of Pennsylvania.