We found that a program of professional interpreter services can increase delivery of health care to limited–English-speaking patients in a large staff model HMO. Patients who used the new interpreter services had a significantly greater increase in office visits, prescription writing, prescription filling, and rectal exams compared to a control group. Disparities in rates of fecal occult blood testing, rectal exams, and flu immunization between Portuguese- and Spanish-speaking patients and a comparison group were significantly reduced after the implementation of professional interpreter services. These findings support our hypothesis that interpreter services enhance LEP patients access to care.
To our knowledge this is the first study to report the effectiveness of an intervention to improve the delivery of health care to a population of limited–English-speaking patients. Multiple studies have revealed the significance of being a limited–English speaker on health3,7,16,17,20
and utilization of physician services.7–10
Other studies have shown that use of interpreters whether trained or untrained can improve patient satisfaction, perceived understanding of disease, and compliance with care and follow-up appointments.21,22
Our study indicates that in an ambulatory care setting a program of professional interpreter services can increase the delivery of therapeutic and preventive care.
There are several mechanisms through which provision of interpreter services could have increased provision of clinical, prescription, and preventive services. The first is through enhanced patient and physician understanding. The services in which there were significant differences between the ISG and the CG may be considered communication sensitive services. Visits may have increased in the ISG because patients are more likely to make and keep an appointment when they are able to adequately communicate with clerical and clinical staff and they understand the importance of the visit. Prescription use may have increased as a result of an improvement in the physician's ability to take an adequate history and answer the patient's questions, increasing the physician's confidence in the diagnosis and the patient's understanding of the risks and benefits of a medication. Patients may have been more likely to fill and refill prescriptions because they understood their purpose and the instructions for taking the medication. Rectal examinations may have increased at such a great rate because adequate communication is essential for consent to and performance of this exam.
Enhanced physician–patient trust and patient satisfaction are two other mechanisms by which provision of professional interpreter services could have increased clinical, prescription, and preventive service use. Increased trust has been correlated with both increased patient adherence and satisfaction,24
and communication is essential to the establishment of trust in the physician-patient relationship. Trust has been shown to be related to communication-dependent physician characteristics such as understanding, caring, clear and complete communication, partnership building, and question answering.24–26
Patient satisfaction among LEP patients may also be communication-dependent. Spanish-speaking Latinos have been found to have lower patient satisfaction scores than both Latino and non-Latino English-speakers,11
and provision of interpreter services have been shown to increase satisfaction among Spanish-speakers.13
While it has not been documented empirically, greater patient satisfaction likely increases patient proclivity to visit their health center and follow health care provider recommendations to return for visits, take medication, and undergo screening.
Several limitations should be considered when interpreting our study's findings. Some of the measures may be difficult to interpret. The interpretation of the need for the increased clinical service and prescription use is limited by the information we have about the health status of the HMO members in the study and the need for those visits or prescriptions. The increase in preventive service delivery could be interpreted as the result of targeted interventions or programs, but no physician or patient programs within or outside of the HMO could be identified during the study timeframe. It could also be argued that the significant increase in rectal examinations is not important because of this screening's questionable value. However, it reflects the provision of appropriate care within the HMO studied because physicians were reminded to do this examination on men of the appropriate age each year.
The study design was constrained by the available data. The sample size of the ISG was small due to the restrictive sampling of continuous enrollment over two years and may not have provided us with sufficient power to detect some effects. The data was abstracted only one year after the implementation of the new interpreter services. One year may have been too short a time to fully assess the impact of the new services. We were also unable to eliminate LEP patients who did not speak Spanish or Portuguese from the CG because data on need of interpreter services or use of ad hoc interpreters in other languages was not consistently collected. However, it was known that the overwhelming majority of patients in need of interpreter services at the four health centers studied were Spanish and Portuguese speaking.
The study may have limited generalizability. It was conducted at a well-established staff model HMO with a highly sophisticated system of interpreter services and care and among enrollees who were continuously insured for an average of more than three years. These services may have had a different impact on a patient population in a different health system or with less familiarity with or less access to a health care system. In addition, the only interpreter services studied were for one group of Portuguese- and Spanish-speaking patients. The results may be different for a group with a different level of acculturation, or other limited–English-speaking or cultural groups.
Finally, the study did not address the questions of improvement in quality of care and health outcomes or cost-effectiveness. Our findings suggest that provision of interpreter services may improve the quality of care delivered to LEP patients, but increased delivery of services alone does not necessarily result in quality improvement or better health outcomes. Given current concerns about cost containment and quality of care in health care, these are important areas for future research.
This is just one of the areas in which more research is warranted. Our findings suggest that current disparities in delivery of care to limited–English-speaking minority groups may be partially explained by communication barriers and that interventions focusing on those barriers can have a direct effect on delivery of care, but this relationship needs to be better elucidated. Important areas for future research include studies in different health care settings with different patient populations that are longer in duration, involve larger populations and examine the impact of interpreter services on delivery of specific services or outcomes. Identifying the mechanisms by which interpreter services impact care and enhance understanding, trust, and satisfaction (or all three) would also allow design of services that maximize their impact.
The physician–patient relationship is dependent on effective communication. Limited–English-speaking patients need to be able communicate adequately with their health care providers if we are to improve access to health care for this large and growing U.S. population. Cultural, educational, and economic barriers still exist for many limited–English-speaking patients, and should be addressed, but providing these patients with the means to inform us about their symptoms and concerns and to navigate health care delivery systems is a necessary first step to improving their health.