Use of a clinical laboratory computer to warn of possible drug interference with test results

Abstract

Drugs can alter the concentration of important biological substances. This alteration can occur during an actual clinical laboratory test procedure for that substance. The frequent administration of drugs, coupled with the increasing reliance on accurate laboratory data, have led us to develop programs which will automatically warn a physician when test results may be altered due to pharmecuticals. Using a clinical laboratory computer system, software has been developed which checks to determine if the result of any test performed on a patient specimen may be affected by any drug administered to that same patient. If possible interference is detected, a comment is automatically attached to the result on the patient's computer-generated report warning the attending physician the result may be falsely elevated or lowered. These programs are run on a laboratory computer system whose central processing unit is a Control Data Corporation, model 1784, computer with 16-bit words and 256K bytes of central storage. All programs are written in Control Data Corporation FORTRAN IV. There are six related programs ranging in size from 560 to 4400 words requiring a total storage capacity of 12,400 words and three data files requiring a total of 213,600 words of storage. The first three programs provide the user with an alphabetized listing of all laboratory result reporting names and are divided to: 1) collect; 2) sort; 3) and print the data. The next program creates a drug/test interference data file which stores information on the effect of a given drug on a variety of laboratory tests. Since patient/drug information may derive from more than one source using different drug code numbers, a program was developed to create or update a data file which serves as a cross-reference index between the laboratory drug number and the pharmacy drug number(s). The final program allows for entry of patient identification and drug data, checks for drug/test interference and, if interference is detected, automatically attaches an appropriate comment to the result in the patient's file. All of these programs operate in a real-time environment.