Quality Control for diagnostic and treatment facilities
Deciding whether to use RDTs or microscopy or a combination of the two for confirmation of a malaria infection is important but an informed decision relies on the assumption that either of the tools will go on to be used in such a way as to ensure the best performance possible.
Quality control of handling
For RDTs, appropriate transport, storage and handling, in-line with the manufacturer’s recommendations, are important to ensure the RDTs remain stable and achieve their reported levels of sensitivity and specificity (rates of false negatives and false positives).
Guidelines for handling and storage of RDTs should be in place and should include recording of the conditions of storage daily. A supervisory structure should be put in place that allows checking of storage facilities at regular intervals.
The FIND manual on storage, handling and transport of RDTs can be accessed here.
Quality control of RDT use and results
- Regular supervisory checks of clinical services should include observation of RDT use to verify that user instructions are being carefully followed. It is advisable to increase supervision if the RDT product is changed as instructions for use vary from product to product.
- Regular quality assurance of results should be conducted. Blood slides should be prepared at the same time as the RDT test for a random sub-set of people tested for malaria. These should be read by a skilled microscopist (either on-site or by a referral laboratory) to confirm alignment with RDT results.
Quality control of microscopy
A random sub-set of blood smears should be sent for cross-checking by an external microscopist, likely to be available in a referral laboratory within the country. The cross-check results should be compared with the on-site results.
Quality control findings should be carefully reviewed each time to identify needs for remedial training of on-site microscopy staff.
The WHO manual on quality control of malaria microscopy can be accessed here. Whilst it is written for an audience of national managers it includes an overview of all the key steps in a quality control process.
Quality control of use of diagnostic results
Whilst a main focus of diagnostic quality control will be to ensure tests are accurate, it is also important to provide quality control for the second step in the diagnostic process which is ensuring the results are used appropriately.
Health clinic record books should require health staff to record details for every person tested for malaria, the means of testing, the result, the actions taken and the staff member responsible.
These records should be regularly checked as part of the quality control process and remedial training undertaken if appropriate.