To the Editor:

H. Gilbert Welch is right to be concerned that patients will forgo diagnostic mammograms, colonoscopies and other kinds of care for serious conditions if they aren’t free, as “prevention” is under the Affordable Care Act (“The Problem With Free Health Care,” Op-Ed, May 1).

Studies show that even patients who need emergency care for a potentially serious problem will go without it if they are in a high-deductible health plan (although this increases their risk of subsequent hospitalization). And therein lies the problem. While cost sharing discourages overuse of medical care, it worsens a greater problem, that of underuse.

In an 11-nation survey by the Commonwealth Fund, more than a third (37 percent) of Americans reported not going to the doctor when sick or not filling a prescription because of cost, compared with a small percentage of people in Britain, Sweden and Norway. The difference: They have single-payer systems in which care is generally free at the point of service.

IDA HELLANDER

Chicago, May 2, 2014

The writer is director of health policy and programs for Physicians for a National Health Program.