Self assessment of pre, intra and post analytical errors of urine analysis in Clinical Chemistry Laboratory of Alexandria Main University Hospital

Abstract

Background: Analysis performed in the laboratory is subjected to variance; hence, every clinical laboratory must have adequate procedures to assure quality of the medical results reported. The definition of a total testing process incorporates the three classical phases of performance in laboratory testing: (1) pre analytical, (2) analytical, and (3) post analytical. Each phase when carried out properly plays an important role in preventing laboratory errors. Aim of the Work: The present study aimed at evaluating the performance of the Clinical Chemistry Unit of Alexandria Main University Hospital regarding urinalysis, through identification of the problems related to the total testing process. Materials and Methods: The study was conducted on 514 consecutive urine specimens that were received at the clinical chemistry laboratory of Alexandria Main University Hospital, during 3 months period from March to June, 2013. Inspection sheets were based upon the integration of the CLSI approved guidelines for urinalysis collection, transportation and preservation, inspection checklist of the CAP, and the review of the literature for similar studies. Results: Regarding the 514 studied request forms for urine analysis, they were found missing some data essential for interpretation of patient test results as recording time of specimen collection and time the specimen received by the lab (11.85%), followed by 462 missing requests and preliminary diagnosis or relevant clinical information (380 requests), which accounted for11.02 and 9.06% errors respectively. The request form was missing other important data as patients' identification, in 29 requests (0.69%), sex in 239 requests (5.7%), age in 208 requests (4.96%), date of specimen collection in 178 (4.24%), tests requested in 30 (0.72%), and authorized physicians' signature in 185 (4.41%). As regards request forms being authorized by a physicians' name or signature, our study showed that almost one third (185) of the request forms of the studied samples, lacked any indication for ordering physician, which accounts for 4.41% of the TTP errors. Also a comparative study was done between the pre analytical errors in the authorized request form and the unauthorized forms, which revealed that there was a high statistical significance difference (P < 0.0001) between the two forms, with errors being much lower in the authorized request forms. In this study the analytical phase showed the least number of errors, 23 errors done in 1970 activities for 514 specimens studied and 0.55% TTP errors. The high frequency in the analytical phase was for error of analysis 0.31% (13 specimens), followed by 6 specimens lost (0.14%), and 4 specimens mixed up (0.10%) out of 514 specimens study sample. Post analytical phase ranks the second in the error frequency in the present study, 487 errors in 1461 activities done for 514 specimens, which account for 11.61% of the TTP errors. As regards studying the post analytical phase, there was no results loss, but also there was no result verification procedure nor age and sex reference ranges in the results report.