How the use of rapid diagnostic tests influences clinicians' decision to prescribe ACTs from ACT Consortium on Vimeo.

Scientific title: Social and economic evaluations of the introduction of rapid diagnostic tests for Malaria alongside a randomised controlled trial in rural health facilities in Ghana

What did we know before this research?
Evidence shows that in many African regions, including Ghana, malaria is massively over-diagnosed. This means that patients who are not diagnosed with malaria by tests that identify malaria parasites in the blood are still considered to have the disease and therefore receive anti-malarial treatment.

Microscopy is an accurate method of diagnosing malaria, but the resources it requires including a skilled microscopist make it difficult to sustain. Also, Ghana is one of the countries where many patients are diagnosed with malaria based on their symptoms, when in some cases they may be suffering from a different bacterial or viral disease.

Rapid diagnostic tests (RDT) are an effective tool to identify malaria parasites in the blood, and are recommended to avoid expensive ACT drugs being wasted when patients are suffering from something other than malaria. However, the cost-effectiveness of this strategy is reduced if health workers ignore the results of the test.

Each country has a different perspective on the use of rapid diagnostic tests. Implementing this tool also depends on how accessible microscopy is, as well as ACT medication. Previous research has found that a number of social, clinical and logistical factors shape the behaviour of clinicians in diagnosing malaria. There is little research on the potential for the new technology of rapid diagnostic tests to change clinical practice in the face of these existing dynamics.

What does this study add?
This study builds on a randomised controlled trial in four health facilities across two settings, one with laboratory services to carry out microscopy and one clinical setting without those facilities. The trial aimed to test the impact that using rapid diagnostic tests can have on clinician behaviour: whether they prescribe ACT drugs in response to test results.

The research team undertook two additional evaluations to explore the reasons behind this behaviour and its cost-effectiveness in practice. The first was a social evaluation which included in-depth interviews with health workers and key stakeholders involved in the trial, as well as focus group discussions with patients who had been tested with RDT during the trial. This evaluation provides a useful insight into the reasons for clinicians’ behaviour as well as the perceptions and expectations that patients have of the tests.

The second was an economic evaluation and involved the development of incremental cost-effectiveness analyses based on data from rural health facilities in Ghana, both with and without microscopy. Introducing rapid diagnostic tests into health facilities where diagnosis was based on symptoms alone increased the proportion of patients who were appropriately treated, while health facilities where microscopy was available there was no advantage to replacing them with RDT.

The research team
Principal Investigator

Dr Evelyn Korkor Ansah, Deputy Director and Head of Research Department, Research and Development Division, Ghana Health Service, Ghana
Email: Ansahekdr@yahoo.co.uk

Other Investigators

Prof Christopher Whitty, London School of Hygiene & Tropical Medicine
Dr. Clare Chandler, London School of Hygiene & Tropical Medicine
Dr. Kristian Hansen, London School of Hygiene & Tropical Medicine
Dr. Shunmay Yeung, London School of Hygiene & Tropical Medicine
Solomon Narh-Bana

Latest on this research
The randomised controlled trial found that in areas where rapid diagnostic tests (RDTs) were introduced and microscopy testing was unavailable, there was a significant reduction in the number of patients being prescribed a malaria drug without having malaria, and there was no evidence that this had caused any clinical harm. However, where microscopy was established already, introducing RDTs did not improve the prescribing practice. In all settings, over 50% patients with a negative test result received an antimalarial.

A social evaluation was conducted after the trial. The practice of health workers appeared to be shaped by experiences with the tests themselves as well as by interactions with colleagues, patients and the research team. For some health workers, these experiences led to a change in practice. For others, existing practice was reinforced. Many of the characteristics of RDTs seemed conducive to change. However, the analysis showed that there was limited support from managers and lack of readiness in the system to change.

The focus group discussions with patients who had been tested with RDTs during the trial showed they had high expectations of the tests. They welcomed the tests as tools that supported the diagnostic process, but they also believed the tests could identify any cause of illness, beyond malaria. Patients therefore expected to be told what was wrong with them after a test, and felt excluded from the diagnostic process where rapid diagnostic tests were adopted, and that clinicians’ authority was still greater than the test results.

The economic evaluation found that in health facilities where diagnosis was mainly presumptive (based on symptoms), the introduction of RDTs increased the proportion of patients who were appropriately treated with antimalarials, from 42% to 65%. This occurred at a societal cost of US$8.3 per additional patient that was treated appropriately. If clinicians improve their adherence to negative results and prescribe fewer antimalarials to patients who do not test positive for an RDT, and the price of the test continues to fall, then the relative cost-effectiveness of diagnosis based on RDT will improve.

 

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