Roughly half of all Medicare patients who are referred to a specialist for treatment by their primary care doctor do not receive that treatment, often because the appointment is never made, new research shows. According to researchers, this is the most frequent error in medicine.

The Indiana University School of Medicine reviewed 6,785 patients aged 65 or older—with a mean age of 72. Investigators discovered that 29% of the time a referral appointment with a specialist was not even made. Of the 71% of appointments that are made, researchers discovered that only 70% of patients actually show up for the appointment, meaning that only 50% of the entire eligible group visited a specialist at all. Results vary from institution to institution but the trend is similar across the country, researchers noted.

Though it is difficult to ensure a patient arrives at an appointment, researchers say there are a number of ways to ensure the appointment is made, including use of healthcare IT and electronic medical records. At the urban medical institution where the study was conducted, researchers used healthcare IT solutions to cut the referral follow through fail rate from 50% to 20%. The study appears in the February issue of the Journal of Evaluation in Clinical Practice.