Low Rates of Testing and Diagnostic Codes Usage in a Commercial Clinical Laboratory

Abstract
Improving outcomes for chronic kidney disease (CKD) requires early identification and recognition by physicians. There are few data on rates of testing or use of diagnostic codes for CKD. A cross-sectional analysis was performed of patients who were older than 40 yr and had one or more laboratory tests between April 1, 2002, and March 31, 2003, at a Laboratory Corporation of America regional laboratory. Objectives were to determine the frequency of testing for serum creatinine; prevalence of CKD, defined as estimated GFR 60 yr were more likely to be tested for serum creatinine with odds ratio (OR; 95% confidence interval) of 2.09 (2.05 to 2.14), 1.22 (1.19 to 1.25), and 1.24 (1.22 to 1.27) respectively. Among patients tested, 30% had CKD. Sensitivity and specificity of kidney disease diagnostic codes compared with CKD defined by estimated GFR 60 years, and CVD, rates of testing and sensitivity of diagnostic codes were 53 and 14%, respectively. Low rates of testing for serum creatinine and insensitivity of diagnostic codes for CKD, even in high-risk patients, suggests inadequate physician awareness of CKD and limited utility of administrative databases for identification of patients with CKD.