Value of multiplex nucleic acid amplification tests (NAATs) in the medical management of lower respiratory tract infections - INAHTA Brief

Aim

The objective of this assessment was to determine the value of using multiplex nucleic acid amplification tests (NAATs) in the management of lower respiratory tract infections in the routine care context. The aim was to define the clinical utility of this procedure, the clinical indications, the infectious agent panels to be screened for, and the role of this procedure in the care pathway for patients with lower respiratory tract infections.

Conclusions and results

NAATs are not recommended in the outpatient care context for acute community-acquired pneumonia. However, they are indicated in the hospital setting in specific contexts, such as epidemic periods, immunosuppression or severe pneumonia. Their use is not recommended for severe bronchitis. For acute exacerbations of COPD, these tests are reserved for use in the critical care setting. Finally, NAATs are not routinely recommended for acute bronchiolitis in infants. Three panels are proposed: the quadriplex panel, the multiplex panel on an upper respiratory tract sample, and the multiplex panel on a lower respiratory tract sample. The composition of these panels is detailed in the assessment report. It should be noted that the use of multiplex NAATs for the identification of pathogens must comply with diagnostic performance requirements, as well as implementation conditions.

Recommendations

The HAS points out that:

• like all diagnostic tests, NAATs should be performed following a physical examination of the patient;
• the diagnostic performance of NAATs is intrinsically linked to the quality of the sample taken, and dependent on the detection window of the specific nucleic acids of the agents concerned. If a sample is not taken in optimal conditions, this can impair the analytical sensitivity, thereby increasing the risk of false negatives and compromising clinical interpretation of the results;
• the performance of a NAAT is only recommended when this could result in a change or adjustment in the patient’s clinical management, in order to maximise the diagnostic relevance and avoid unnecessary tests with no impact on the treatment strategy;
• their results must be delivered within a time frame compatible with optimal patient care.

Methods

The HAS’ standard method for the assessment of professional procedures was used to meet these objectives. This method included: i) a systematic literature search performed using PICOTS selection criteria, with a critical analysis of published evidence using the GRADE methodology, ii) the consultation of individual experts (professionals and patients), and iii) collection of the perspective of stakeholders (professional bodies and patient associations) concerned by the subject.

 Further research/reviews required

Impact of syndromic multiplex NAATs on outpatient care

• Reduction of antibiotic resistance: further research is needed to understand how syndromic tests can contribute to the more targeted use of antibiotics and reduce the emergence of resistance. Current data are inadequate in the outpatient setting to draw any definitive conclusions.
• Optimisation of antibiotic prescriptions: studies are required to analyse changes in antibiotic prescribing practices following the introduction of syndromic tests. The real impacts on the management of respiratory infections in outpatients need to be better documented.
• Medico-economic assessment: there is a lack of data concerning the costs and economic benefits of syndromic tests in outpatient care. Further research is needed to assess the potential savings associated with a reduction in unnecessary prescriptions and hospitalisations avoided.
  Delocalisation of diagnostic tests to outside healthcare organisations.

• Improvement in outpatient care: the potential impact of improved outpatient care. It is necessary to study the potential impact of delocalising diagnostic tests (virological, bacteriological, and other tests) to outside the hospital setting on the speed and efficacy of outpatient care, and on the improvement of accessibility and reduction in diagnosis times. Current data are insufficient, and this promising research avenue is worthy of further attention.
• Clinical and medico-economic data: it is necessary to study the clinical impacts (e.g. reduction in exacerbations of chronic respiratory illnesses) and economic impacts of this approach. The advantages and challenges of implementing these strategies in an outpatient care context have not yet been adequately documented, making this an essential research avenue.