Luis Ascanio, 61, works as a medical interpreter at La Clinica del Pueblo, a D.C.-based clinic geared toward providing health care to the surrounding Latino community.

Fluent in Spanish and French, he helps doctors talk with patients with limited English skills about health care issues that range from highly technical to deeply emotional. “You are sort of a bridge,” he said. “And it is very important that you do not obscure the context of the conversation.”

But according to an analysis published Monday in Health Affairs, more than a third of the nation’s hospitals in 2013 did not offer patients similar language assistance. In areas with the greatest need, about 25 percent of facilities failed to provide such services.

The researchers examined survey data collected from 4,514 hospitals nationwide by the American Hospital Association. In addition, they categorized the hospitals as to whether they offered language services and by their ownership status — private not-for-profit, private for-profit or government-owned. The researchers also calculated the number of residents with low English proficiency in the facilities’ service areas using census data collected from 2009 to 2013.

They concluded that about 69 percent of hospitals offered language services. Hospitals serving areas with moderate needs provided proportionately more assistance than facilities located in low- or high-need areas.

“And I think we can do better,” said Melody Schiaffino, lead author and associate professor in the Graduate School of Public Health at San Diego State University.

Private not-for-profit hospitals were the facilities most likely to offer language services. Yet, in areas with the greatest need, about 36 percent did not have systems in place. In areas with low need, seven out of ten facilities had the capability.

Government-owned and private for-profit hospitals were far less likely to provide such help. Less than a fifth of private facilities offered language aid. Government hospitals had similar rates.

Researchers found no pattern to explain which facilities provided language assistance. This inconsistency suggests patients go to hospitals that may be outside their official service area based on language services, Schiaffino said, resulting in higher costs for the facility and longer waiting periods for patients.

Further research is needed, the authors wrote, because immigration patterns are leading to new areas of language-diverse communities. Models need to be developed to predict where these pockets will emerge and what the level of need for assistance might become.

“A lot of hospitals probably are not aware of the change in diversity and the scale of diversity in their community as they think,” said Schiaffino.

According to the study, 60 million people claim a primary language other than English. Spanish speakers alone account for more than 10 percent of the American population in 2011, according to the Census Bureau.

Based on civil rights law, any hospital receiving federal funds must have language services available for its patients. However, many patients do not know their right to access language services, the study noted, which could become more challenging as private for-profit hospitals — the kind least likely to offer this kind of help — continue to grow in market share.

But the challenge also provides an opportunity for hospitals to empower their customers to be informed patients.

“To receive a diagnosis in the language that you prefer is not an unreasonable request,” Schiaffino said.