The clinical benefit of point-of-care testing

Despite the fact that self-monitoring of blood glucose (SMBG) apparently accounts for an amazing 20 % of the expenses of the total in vitro diagnostic market worldwide (27 % in the US), there remains a woeful lack of evidence that SMBG is actually effective in improving the clinical outcome of diabetic patients. 

In fact there is a paucity of evidence for the benefit of point-of-care testing (POCT) generally, according to the most comprehensive report of the evidence base for POCT yet published. Under the auspices of the US National Academy of Clinical Biochemistry, 13 groups of experts were charged with a systematic review of the literature relating POCT to clinical outcome. 

Each group focused on one area of POCT (diabetes, coagulation, critical care, neonatal jaundice, infectious disease, etc.) and no area of POCT escaped attention. The evidence of benefit for each POCT was graded 1-3. The highest level 1 was awarded if the benefit of POCT was supported by "consistent results from well-designed, well-conducted studies in representative populations". 

Of 103 recommendations relating to the adoption of point-of-care tests, only 18 could be based on level 1 evidence. These included glucose monitoring of the critically ill, HbA1c monitoring of diabetic patients and annual fecal occult blood testing for colorectal cancer screening. 

The point-of-care tests that could not be recommended because there was no evidence of benefit included transcutaneous measurement of bilirubin in neonates, testing for group B streptococcus and magnesium measurement in the critically ill. In an accompanying entertaining editorial, a US laboratory director praises the expert analysis and identifies the report as an essential reference that "summarizes all POCT available today …". 

Clearly disappointed (and surprised?) by the lack of a real evidence base for the benefit of many point-of-care tests, she makes a plea for laboratory professionals to be more proactive in initiating studies that will provide the level 1 evidence needed for confident implementation of POCT.