The introduction of electronic medical records (EMRs) reduced visits to primary and specialist outpatient care in two regions covered by the US health maintenance organisation Kaiser Permanente, according to a new study.

Both regions – Colorado with 367,795 Kaiser Permanente members and Northwest with 449,728 – experienced significant decreases in use of services over the two year period in which the EMRs were introduced.

The age adjusted number of total office visits per member in the second year decreased by 9% compared with the first year, and age adjusted primary care visits decreased by 11%. Age adjusted specialty care visits decreased by 5% in Colorado and 6% in the Northwest.

The study, published in the British Medical Journal looked at other possible reasons for the reductions in visits, such as increased use of emergency departments or inadvertent reductions in access to services, but found no concomitant changes that would account for the decrease in visits.

In the Northwest an increase was found in scheduled telephone contact between patients and clinicians; contact rose from a baseline figure of 1.26 contacts per patient per year to 2.09 contacts after two years. The study found that electronic records made telephone contacts more effective.

Use of laboratory and radiology services did not change conclusively. Selected measures of quality remained unchanged or improved slightly.

The study authors conclude: “Readily available, comprehensive, integrated clinical information reduced use of ambulatory care while maintaining quality and allowed doctors to replace some office visits with telephone contacts. Shifting patterns of use suggest reduced numbers of ambulatory care visits that are inappropriate or marginally productive.