Californians are increasingly worried about high health care costs, and more are postponing or skipping medical treatment altogether because of it, according to a new report by the California Health Care Foundation, a nonprofit that researches health care trends.

Fifty-one percent of California residents skipped or delayed seeking physical, mental or dental health care in the last 12 months because of cost concerns, according to the report, which surveyed 1,408 adults living in California in late 2019. That is up from 44% a year earlier.

People skipped recommended tests or treatment, did not fill prescriptions, cut pills in half or skipped a dose. Among those who skipped or delayed care because of costs, 42% said their health condition got worse.

Californians are increasingly worried about costs associated with many parts of the health care system: 69% of respondents said they were worried about unexpected medical bills (up from 63% the previous year), 66% were worried about out-of-pocket health care costs (up from 56%), and 50% were worried about prescription drug costs (up from 42%).

Notably, a higher proportion of Californians are worried about certain types of health care costs than about housing costs, the survey found. Sixty-nine percent of residents were worried about unexpected medical bills and 66% were worried about out-of-pocket costs. Both are higher than the 54% of residents who worried about rent and mortgage.

“In a high-cost state like California, that people are more worried about medical expenses than housing, that is really surprising,” said Kristof Stremikis, director of market analysis and insight at California Health Care Foundation, which conducted the survey with SSRS, a survey and research firm. “I think it says something about what a huge issue health care costs have become in the state. It’s very disturbing.”

The survey respondents had a mix of health insurance plans — some were covered by employer-sponsored plans, some were on Medi-Cal (the joint federal-state health insurance program for low-income residents), some were on Medicare (the federal government insurance program for seniors) and some did not have any insurance.

Uninsured residents were much more likely to struggle with paying for health care services. Forty-five percent of uninsured adults said they struggled to pay medical bills, compared to 33% of Medi-Cal recipients. But even many with commercial insurance struggled: 20% of people with employer-sponsored plans said they had trouble paying medical bills. Respondents who struggled to pay medical bills said they tried reducing spending on necessities like food and clothing, used up most or all of their savings, increased credit card debt, took on an extra job or hours and borrowed money from a friend or family member in order to pay off medical bills.

And many who sought care struggled to pay for it: nearly 1 in 5 Californians said they or someone in their family had problems paying or were unable to pay medical bills in the past 12 months.

“Unfortunately, things are getting worse on a lot of fronts,” Stremikis said. “People are finding it more difficult to pay for health care, having more cost-related access problems, and they’re getting sicker as a result. Health care costs are now a public health issue.”

Catherine Ho is a San Francisco Chronicle staff writer. Email: cho@sfchronicle.com Twitter: @Cat_Ho