The quality of creatinine measurement in Thai clinical chemistry laboratories, 2021-2022

Abstract

             Chronic kidney disease is a public health problem at the national level. Only 1.9% of Thai people know that they have kidney disease. Therefore, the detection and treatment of chronic kidney disease at an early stage could prevent or delay the occurrence of late-stage renal disease. Furthermore, it could reduce the rate of illness or premature death. Estimated glomerular filtration rate is the most useful indicator of kidney function and kidney disease progression using serum creatinine and individual features calculated in the formulas. The accuracy of creatinine test results will lead to the more effective diagnosis. This study was based on data from the results of the quality assessment reports for creatinine analysis of clinical chemistry laboratories during the fiscal year 2021-2022 and the level of quality of the analysis was presented with a z-score to indicate the level of quality and competency of creatinine testing from participant laboratories in Thailand.

             The study results were obtained from External Quality Assessment or Proficiency testing program, fiscal year 2021, 772 laboratories, and fiscal year 2022, 797 laboratories. A study of the quality level of creatinine analysis using an interlaboratory comparison of analytical results of laboratories in both public and private sectors throughout Thailand.  It was found that 96.89 percent of total laboratories were capable to analyze creatinine accurately (Accuracy) with a score of “Between laboratories z-score” less than 3 in the test subjects with a normal concentration, and 93.48 percent from total laboratories passed the same criteria by analyzing the sample with a higher concentration of creatinine than normal concentration. For analytical precision (Precision) indicated by within laboratories z-score less than 3, the number of laboratories analyzing the proficiency test item for creatinine at normal concentrations passed the criteria of 90.28 percent, and creatinine concentration higher than normal passed the criteria of 92.97 percent. Although, more than 90 percent of laboratories passed the quality assessment criteria for analytical testing. However, 3.11 to 6.52 percent of laboratories did not meet the criteria for the creatinine assay on the accuracy of the analysis results.  Whilst laboratories 7.03 to 9.72 percent that the results of the creatinine analysis did not pass the criteria on the precision of the analysis results.  The number of laboratories failing the criteria was significantly higher with testing based on Jaffe reaction than the other method (P<0.05).

             Therefore, it is necessary to establish a good internal control system and promote the development of quality systems urgently. This will lead to an effective quality assurance system for the laboratory which will truly be of the utmost benefit to service users.