28th October 2022, Dr Chee L Khoo
Point-of-Care Testing (POCT) is defined as laboratory testing conducted close to the site of patient care, typically by clinical personnel whose primary training is not in the clinical laboratory sciences, or by patients (self-testing). In theory, POCT which produce results within minutes can assist in management of a number of chronic diseases. It could be useful in patients whose adherence to appointments is often an issue or in patients who are time poor and would prefer to attend the practice as infrequently as possible. There are possible cost issues too as POCT in general, cost the health system less compared with the traditional laboratory testing. With those considerations in mind, I thought I might venture into utilising POCT in my practice.
Before we embark on the plan to incorporate POCT into the practice, there are a few questions that need to be addressed:
Effectiveness – accuracy, reliability and reproducibility
Imrit, C. et al conducted an evaluation of the precision and accuracy of the cobas b 101 (1). 2 control samples were analysed 11 times and over 11 days and compared with laboratory machines (Tosoh and Seimens machines). They found “good correlation with the laboratory method and acceptable precision.” The accuracy and precision for values between 4-14%. Similarly, Tirimacco, R. et al found the cobas b 101 to have “with good precision, correlation, and user satisfaction results”(2).
When the Australian Department of Health and Aging conducted the “The Point of Care Testing in General Practice Trial” in 2009, it compared the POCT results with pathology laboratory tests results (3). For HbA1c, POCT results were 0.0504% below the corresponding pathology laboratory test results. On average, POCT results were 0.2645mmol/L below the corresponding pathology laboratory test results for total cholesterol and 0.0694mmol/L below the corresponding pathology laboratory test result for HDL-C. For triglycerides, POCT results were 0.2014mmol/L above the corresponding pathology laboratory test result on average.
Cost
Medicare now has an item number for performing a POCT for HbA1c but there are only for patients with diabetes and you can do them only 3 times per year. The rebate for HbA1c pretty much equates to the cost of the cartridge to perform the test. The Medicare rebate for Item 73812 = $11.80 and the cost per cartridge is $10.65. There is no re imbursements for lipid testing.
Cost-effectiveness
In the DOHA trial, a societal perspective was applied to the calculation for comparative costs between POCT and pathology laboratory testing. HbA1c and lipids did not generate a statistically significant difference in the direct costs per patient to the health care sector over the duration of the trial. For all PoCT strategies, there was a small reduction in patient travel costs and in indirect costs. Lipid testing led to a higher costs per patient of pharmaceuticals.
Cost-effectiveness was determined using the Incremental Cost Effectiveness Ratio (ICER). Both the lipid and HbA1c testing, there were health gains but there were extra costs. For HbA1c, this was $40 per additional patient within the therapeutic range and for lipids, this was $10,082 per additional patient within the therapeutic range.
Clinical Effectiveness
Does the availability of POCT at the practice improve clinical care? In theory, by providing instant results to the patient during the one consultation and then make adjustments to treatment, it can improve adherence and reduce treatment lag and possibly treatment inertia. It is supposed to save the patient and doctor time by condensing everything into one day. In practice, does it translate to improvement in clinical care?
Bubner et al compared POCT with laboratory testing 53 Australian general practices in urban, rural and remote areas across three Australian states, September 2005 to February 2007 (4). 4968 patients with established type 1 or type 2 diabetes, established hyperlipidaemia, or taking anticoagulant therapy were randomised to either the intervention group (3010 patients in 30 practices) and had blood and urine samples tested by PoCT devices in their general practices or the control group (1958 patients in 23 practices) and had samples tested by their usual pathology laboratories. For all tests except INR and HDL cholesterol, the PoCT approach demonstrated the same or better clinical effectiveness than pathology laboratory testing. Not terribly exciting study, is it?
Gialamas et al explored 9 papers from 6 randomised control trials where POCT were compared to pathology laboratory testing (5). They found that POCT were cost-effective compared to usual care or that patients. Health professionals found PoCT satisfactory. However, there was no robust evidence that PoCT in general practice improves patient health outcomes.
That was what was planned at the practice from day one. We arranged for patients to come about 15 minutes earlier, see the nurse to have the POCT testing done, then pop over to see me after that to discuss the results and adjust treatment accordingly. It happened in a few patients but then there were some issues with machine playing up. It would do the lipids but not the HbA1c which is more crucial in day-to-day adjustments of treatment. We also have to separately test the fasting glucose on a glucometer and send the urine away for urinary albumin-creatinine ratio.
There was a further issue with Medicare billing. When patients come in, they may be due for a feet check, an ABI, an ECG and a retinal scan. This is in addition to the usual BP and weight check. Naturally, these are all done by the practice nurse before they see me. When appropriate, we can claim an annual cycle of care item because all has been done. However, if I were to see them in a consult to discuss treatment changes based on their POCT tests, I will not be able to claim a consultation item even though it is different from the annual cycle of care item. Ordinarily, I could absorb the cost of the lipid testing into the consultation but without the consult item, I will be actually losing money.
There is a further issue of needing to check the biochemical parameters. We need to check on EUCSs, LFTs, iron studies and a blood count at least once if not twice a year. This will necessitate a full blood test anyway. All in all, it was challenging to check who needs a full blood test and who needs a POCT.
Thus, did the availability of a POCT analyser at the practice improve glycaemic and lipid control? The use of POCT was so hap hazard that we really couldn’t see any changes in care for the better or worse. We ended up having to get the patient to come in to see the practice one day to have all the bloods and investigations done and come back another day to see me to discuss all the results which was exactly what it used to be.
Perhaps, if we target the use of POCT in select patients, we may get better results. Back to the drawing board for now.
References:
- Imrit, Chetanand BSc*; Neergheen-Bhujun, Vidushi S. PhD†; Joonas, Noorjehan PhD*. Evaluation of the Roche Cobas b 101 Glycosylated Hemoglobin Point-of-Care Analyzer. Point of Care: The Journal of Near-Patient Testing & Technology: September 2017 – Volume 16 – Issue 3 – p 135-137 doi: 10.1097/POC.0000000000000142
- Tirimacco, Rosy BSc*†; Cowley, Penelope J. BLabMed*; Simpson, Paul A. BLabMed*; Siew, Limei BMdSc*; St John, Andrew PhD, MAACB, FFSc (RCPA)‡; Tideman, Philip A. MBBS, FRACP*. Point of Care Testing for HbA1c in Primary Care—cobas b 101 Instrument Evaluation. Point of Care: The Journal of Near-Patient Testing & Technology: December 2016 – Volume 15 – Issue 4 – p 129-131 doi: 10.1097/POC.0000000000000106
- POINT OF CARE TESTING IN GENERAL PRACTICE TRIAL FINAL REPORT January 2009. https://www.appn.net.au/Data/Sites/1/SharedFiles/Publications/200901-poctfinalreport27jan09amended5feb09.pdf Accessed 27/10/2022
- Bubner et al. Effectiveness of point-of-care testing for therapeutic control of chronic conditions: results from the PoCT in General Practice Trial. MJA June 2009. https://doi.org/10.5694/j.1326-5377.2009.tb02590.x
- Gialamas A, St John A, Laurence CO, Bubner TK; PoCT Management Committee. Point-of-care testing for patients with diabetes, hyperlipidaemia or coagulation disorders in the general practice setting: a systematic review. Fam Pract. 2010 Feb;27(1):17-24. doi: 10.1093/fampra/cmp084. Epub 2009 Dec 6. PMID: 19969524.