Electronic health records may not have the cost-saving benefit experts have long agreed upon. Savings, estimated by RAND Corp. to be as high as $80 billion a year, has been the justification for billions in federal spending to encourage doctors to go digital. But a study published Monday in the journal Health Affairs found doctors with access to computerized records ordered tests on 18 percent of patient visits, while doctors relying on paper records ordered tests on 12.9 percent of patient visits. Proponents for digital records were critical of the study for using data from the National Ambulatory Medical Care Survey, which is intended mainly to assess how medical care is practiced. The study in Health Affairs did not explore why doctors using computerized records would order more tests.