Point of Care Polymerase Chain Reaction (PCR) Diagnostics of Respiratory Tract Infections in General Practice

The present study will assess the effect and cost-effectiveness of the availability of point-of-care (POC) PCR testing, in respiratory tract infections (RTIs) in general practice, compared with usual care.

Background: Respiratory tract infections (RTIs) are frequent reasons for medical consultations and diagnostic accuracy is important to ensure appropriate treatment. It is important for the quality of the healthcare system that patients are diagnosed as fast as possible and that the GP and the patient are reassured about the diagnostic accuracy. If not, the patient may be unnecessarily concerned and contact health services again.

Re-contacts are costly for society, but they may also be unsatisfactory to the patient and the clinician, because many re-contacts may indicate that tentative diagnosis or treatment were not successful and that in some cases the patient needs to contact health services again to get a sufficient answer or to be reassured that nothing is dangerous.

The introduction of POC PCR in primary care settings has demonstrated significant improvements in appropriate antibiotic prescription patterns in high income countries. In Denmark around 88 pct. of all prescription drugs are issued by general practice, as is the vast majority of the total antibiotics consumption in the healthcare system.

Antibiotic overuse may lead to microbial resistance and if the overall consumption is not reduced, infections with resistant bacteria will be a major problem for both patients and healthcare systems. Due to diagnostic uncertainty, GPs may in some situations prescribe antibiotics also in cases where the patient's symptoms are caused by a viral infection.

Further, if antibiotics are not prescribed, the patient may reconsult their GP or the out-of-hours services due to feelings of uncertainty.

Aims: The aim of the study is to evaluate the effect of POC PCR availability in general practice on 1) the number of re-contacts for patients with symptoms of RTIs, 2) the number of hospital admission, 3) deaths, 4) the number of redeemed antibiotic prescriptions, 5) costs, 6) health-related quality-of-life, 7) cost-effectiveness compared to usual care and 8) GP satisfaction.

Furthermore, a qualitative process evaluation will be conducted throughout the trial.

Methods This study is a cluster-randomized crossover, non-blinded superiority trial with a 1:1 allocation ratio. The procedure for randomization takes outset in the clinics' identification numbers as units. The trial consists of two periods of seven weeks (intervention and control). Care-as-usual is used as a comparator. The study is approved by the local regional ethics committee.

The effectiveness study and the cost-effectiveness study will be based on questionnaire data and data from the unique Danish national registries. Information from the different registers will be linked by the patients' Danish Personal Identification Number. Outcomes based on questionnaire data will be collected at baseline, day 7, 14 and day 28 after the initial visit.

GP and patient recruitment:

General practices in 4 out of 5 Danish regions have been invited to participate. GPs have been invited through a written letter and regional newsletters sent to all GPs in Denmark in March 2023. The GPs has been assigned at random to start as intervention or control practice. Based on sample size calculation, the goal was to include 100 GP clinics.

Each practice is asked to register all patients with symptoms of respiratory tract infections consecutively. The GPs are informed that it is entirely up to them and their clinical judgement to make a decision about whether or not they deem it relevant to employ the POC PCR-test device in the consultation with the patient.

Eligibility Criteria:
Inclusion criteria:

* GP clinics are eligible for participation when they have a clinic provider number ("ydernummer").
* Any patient with symptoms of RTI independent of age, gender, socioeconomic factors are eligible for POC PCR testing, if the GP finds it clinically relevant.
* Questionnaire data will be collected from patients ≥15 years old, parents/caregivers to patients ˂15 years and GPs.
* Qualitative data will be collected from consenting patients and/or parents/caregivers to patients \<15 years and healthcare staff

Exclusion criteria:

- Questionnaire data of participants below 15 years