Trading in options and futures comparison between editions
The main sources of errors are: deficient quality in patient record files, errors in diagnostic coding and in recoding from ICPC-2 to ICD-9-MC. Our source of information for prescription cost was the patient electronic files, which records information of printed prescriptions. This is an overestimation of real cost invoiced to the health system for several reasons: a prescription might be printed several times because of technical problems.
Also, not all patients with a prescription go to the pharmacy store to get the drug. As a result of this, the real pharmacy cost invoiced to the health system is not as high as that obtained from the patient electronic file.