Lack of communication between doctors and patients often causes an adverse impact on the outcome of the treatment of diseases, a new study has indicated.

Researchers from Penn State University conducted a research project to understand how this communication gap affects the outcome of medical practice. The study involved 29 primary care physicians and more than 200 patients.

The doctors and patients were asked to fill out a questionnaire that attempted to measure their beliefs about the illness or condition they were being seen for, including the underlying cause for the illness, the extent to which the disease was controllable, how much their behavior was to blame for the illness and the impact of the illness on their life.

On analyzing the responses, the researchers found major differences in the perception of doctors and patients on matters affecting health.

"We found significant differences in what the patients believed about their health and what the doctors thought the patient believed," says study author Richard Street Jr., a professor of communication at Texas A& M University and director of the health decision-making and communication program at Baylor College of Medicine in Houston.

The underlying cause of this disconnect is a lack of communication, researchers said and noted that patients who were able to ask questions, voice opinions and share concerns -- were better understood by their doctors.

"When patients speak up, stating their preferences, their beliefs and their concerns or worries, doctors get firsthand information about what patients think. It's not surprising that doctors would get a better understanding of their patients," says Dr. Street.

A detailed report of the research project has been published in the online issue of the Journal of General Internal Medicine. The study, however, found no association between the number of times a patient had seen a doctor and how well they understood each other.