Abstract
Evidence-based medicine is part of the multifaceted process of assuring clinical effectiveness and providing optimal clinical care for the patient. A systematic review of near patient test evaluations in primary care published in the BMJ (1999;
Point of care testing is thought to have many advantages in the provision of patient care with fast turnaround times facilitating improved clinical management, and patient satisfaction. Self-monitoring of blood glucose in people with non-insulin-treated diabetes is thought to improve glycaemic control. But what is the evidence base for this?
These two papers address these issues and the outcomes are significant.
Farmer et al. investigate whether self-monitoring of glucose can improve glycaemic control in non-insulin-treated patients with type 2 diabetes. The participants in this study had reasonably well-controlled diabetes with a mean HbA1c of 7.5%. Three cohorts of independently randomized patients were involved. The control group had the usual measurement of HbA1c every three months and two intervention groups performed blood glucose self-monitoring. One intervention group had interpretative advice from their doctor, while the others were self-monitoring more frequently and were educated in interpretation and application of the results in an attempt to enhance motivation. The study looked at various outcomes after 12 months, primarily the HbA1c concentration, but also blood pressure, lipid concentrations and body mass index. No difference was found in HbA1c concentrations between the groups (P = 0.12), and the only variable which reached significance was total cholesterol (P = 0.010). Therefore, this study provides evidence that the costly self-monitoring of glucose in reasonably well-controlled patients does not provide a significant benefit.
Stone et al. were also unable to confirm actual advantages of near patient testing (NPT) for HbA1c. Their randomized control trial, performed in Leicestershire, used surveys and interviews to assess any differences in patient satisfaction between the NPT group and the laboratory testing cohort. Eight volunteer general practices were involved in both rural and urban locations and the study looked at 344 patient responses.
High levels of patient satisfaction existed for the routine measurement of HbA1c in the laboratory and surprisingly many patients in this study were not opposed to the extra appointments required. No preference was seen for either venepuncture or fingerprick testing. So while the interviews indicated that the NPT was highly acceptable to patients and staff, the high pre-existing levels of satisfaction in the laboratory service negated any significant difference.
This study did not attempt to investigate other possible benefits of HbA1c NPT nor did it consider the cost implications of an NPT service or the associated issues of quality control.
Evidenced-based medicine dictates that clinical practice should follow proven benefits to patient outcome, cost or satisfaction. These papers indicate that point of care testing for HbA1c and glucose in these specific clinical settings did not improve patient satisfaction or clinical outcomes. The cost, effort and time implications for providing such NPT is significant and resources may be better invested elsewhere where an evidence base exists.