The Cost-Effectiveness of PIMA Alere CD4 Analyser for CD4 Counting in HIV Patients
The monitoring of absolute CD4 T-cell levels remains an important prognostic marker in the management of HIV infected individuals. The gold standard for CD4 counting is flow cytometry using a FACSCalibur test, which provides results within 24-48 hours. New point of care testing (POCT) for CD4 cells counts could be useful in streamlining patient pathways, with potential benefits in terms of anxiety, time, prompt antiretroviral treatment and costs. A new POCT, the Pima Alere CD4 Analyser, which provides results within 20 minutes, has been introduced in London in 2012.
Objectives:
Aim of this study is to assess the cost-effectiveness of the new Pima POCT compared to the standard FACSCalibur.
Methods:
Two care pathways for CD4 testing are compared: the current care pathway, where patients are tested with FACSCalibur and then recalled for a consultation in the following weeks and the new pathway incorporating the Pima Alere CD4 Analyser POCT, where results are delivered the same day and a consultation is performed immediately without recall. Newly diagnosed and stable patients were prospectively recruited in two phases: prior to and following the introduction of the PIMA Alere POCT. A self-completed questionnaire was administered to all patients to capture relevant socio-demographic and clinical information, service utilization, anxiety levels, time spent in clinic and private costs. Further information on costs associated with each pathway was collected using available administrative data on staff pay, overhead costs, materials and a work diary to monitor time taken to complete activities. Patients’ private costs were assessed, in terms of productivity loss for time taken off-work to attend the clinic, transport costs and other costs. Transport costs were extrapolated over a year for both PIMA and laboratory testing pathways, using the expected number of planned patient visits both prior to and following the introduction of PIMA testing. Clinical pathway data were compared to assess the impact of POCT in terms of costs and outcomes using STATA 12.
The study has adopted both the NHS organisation and the patients’ perspective. A Markov model was created in Tree Age Pro to evaluate the cost-effectiveness of the new test. Probabilities, costs and outcomes were used to populate the model using cycles of 6 moths testing over the patient’s lifetime.
The incremental cost effectiveness ratio (ICER) per life-year gained is reported and a sensitivity analysis has been performed to assess the robustness of the model.
Results:
The results of the Markov model show that Pima-POCT has an incremental cost-effectiveness ration (ICER) of £12,359.39 per life year gained and is therefore cost-effective compared to FACSCalibur in this setting.
Pima-POC saves £2,662.44 per patient per CD4 test and adds 0.22 life years compared to FACSCalibur.
Conclusions: This is the first study to demonstrate the cost-effectiveness of the Pima POCT compared to FACSCalibur. It contributes to understand not only the economic impact on the NHS, but also the economic and psychological effects on patients, helping decision-makers to reduce the financial burden of HIV at societal level.