National Survey on Delta Check Practices in Clinical Laboratories Across Pakistan.

Background: Delta check is a quality control tool in clinical laboratory that compares a patient's current test results with previous ones. It is often considered to be a useful tool to identify pre-analytical errors. Delta check procedures vary across labs. A survey was conducted to determine national delta check practices. Method: An online survey was sent to pathologists. Data was analyzed by Microsoft excel and figures were generated via R statistical software. Results: The survey was sent out to 84 participants. There were 30 (35.7%) final responses, after exclusion of duplicates and incomplete entries. Respondents varied in their designations from Professor 2(6.7%) to Assistant Professor 10(33.3%). Most respondents 25 (83.3%) were Fellows of College of Physicians and Surgeons, while there were 3(10%) PhDs. Work experience varied from less than 3 years, 5(16.7%) to more than 10 years, 17(56.7%). 25 labs surveyed were from tertiary care hospitals. Most laboratories were in Sindh Province, 13 (43.3%). Delta check procedures were used by 19(63.3%) labs, of which 6(31.6%) used automated checks, 12(63.2%) had defined delta limits for different tests, 15(78.9%) had defined time limits to check delta results, 17(89.5%) had a checklist for its investigation and 10(52.6%) had a Laboratory Information System or middleware to block failed delta results. Most of the respondents considered the smallest available option as the ideal delta difference value for blocking results. Conclusion: Delta check procedures vary among surveyed labs and efforts are required for the formulation of national guidelines to synchronise and standardize delta check practices.