Study design & setting
The RSV ComNet study was set up as a prospective cohort study in primary care with a follow up of 30 days. For each child (< 5 years) included in the study, data collection was performed at three moments in time, namely at the day of swabbing (Day 1), and after approximately 14 and 30 days. The disease burden protocol and the procedures for patient recruitment and data collection are described after the data analyses paragraph. To evaluate the disease burden protocol, we aimed to collect 400 swabs in Italy and 200 swabs in the Netherlands.
Data analyses
For the evaluation of the disease burden protocol we used descriptive statistics to examine the feasibility of 1) patient recruitment, i.e. the weekly number of children swabbed, percentage of positive RSV cases, and the response rate on questionnaires, and 2) data collection procedures, i.e. the timing of questionnaires, duration time to complete the Day-14 and Day-30 questionnaires by parents, and the number of children recovered after 14 days. Moreover, descriptive statistics were used to present the baseline characteristics of the children included in the study. All analyses were conducted with Stata SE version 15.0 (StataCorp, 2013, College Station, TX).
In addition, we performed a qualitative process evaluation to assess the feasibility of the patient recruitment and data collection procedures using the experiences from the paediatricians, GPs, and the two research teams. In Italy the paediatricians were interviewed about their experiences through a structured questionnaire. In the Netherlands, GPs who attended the Annual Sentinel Network meeting were asked about their experiences. In addition, research nurses in Italy observed whether parents did understand the questions.
Disease burden protocol
Eligibility criteria participants
Inclusion criteria were children, aged < 5 years, consulting a physician in primary care i.e. paediatrician or general practitioner (GP) with symptoms of an acute respiratory infection (ARI), and a laboratory confirmed diagnosis of RSV. The ARI case definition was based on the definition published by the World Health Organization (WHO) for community based surveillance [21, 22]. For this study we added the criteria: the physician judged that the illness is due to a respiratory infection. Exclusion criteria were insufficient knowledge of the national language by the parents, and insufficient intellectual abilities of the parents to complete the questionnaires.
Measurements and follow-up
At day 1 a nasopharyngeal swab or a nasopharyngeal and oropharyngeal swab was taken, and the physician completed a short questionnaire (Day-1) for each child (Fig. 1). The questionnaire included information about patient demographics, date of onset of symptoms, presenting symptoms and some relevant medical history of the child, and was based on a shortened version of the WHO surveillance form [23].
The swabs collected at day 1 were tested in medical diagnostic laboratories using multiplex RT-PCR. In addition, data regarding the weekly number of swabs, percentage of RSV positive cases, number of coinfections and RSV subtype were collected.
After approximately 14 days, the first parental questionnaire was completed regarding health care use of the child for the RSV infection, days of illness, socio-economic impact and current health status. The questionnaire was based on a previous study which investigated the disease burden of influenza and was adapted for the purposes of our population by the research team [24].
After approximately 30 days, the second parental questionnaire was completed. Quality of life was measured using the Paediatric Quality of Life Inventory (PedsQL)™ 4.0 generic core scales and PedsQL™ 4.0 infant scales. The parent-proxy report of the PedsQL™ 4.0 generic core scales is developed for children aged 2–18 years. The parent-proxy report of the PedsQL™ 4.0 infant scales has different versions for the age categories 1–12 and 13–24 months [25]. All PedsQL™ questionnaires were linguistically validated for the Italian and Dutch language. The PedsQL™ 4.0 generic core scales has shown good internal consistency and reliability, the initial measurement properties for the PedsQL™ 4.0 infant scales demonstrates that these versions may be utilized to measure the generic HRQoL [26,27,28] Questions regarding health care use and socio-economic impact were repeated when the child was still hospitalized after 14 days.
Patient recruitment and data collection procedures
Italy
In Italy, children were recruited for the study and asked for informed consent by the paediatricians during the consultation. A network of paediatricians was established in two Italian municipalities: Rome (Lazio region) and Bari (Puglia region). The paediatricians (12 in each region) swabbed all children meeting the WHO ARI case definition and completed the Day-1 questionnaire. Swabs were sent by courier in the Lazio region and by parents of children swabbed in the Puglia region to the medical diagnostic laboratories (OBPG hospital or University of Bari). Specimens were analysed using a commercial kit multiplex RT-PCR (Allplex™ Respiratory Full Panel Assay) for 16 viruses (including Adenovirus, Influenza A, Influenza B, Parainfluenza 1, Parainfluenza 2, Parainfluenza 3, Parainfluenza 4, Respiratory syncytial virus A, Respiratory syncytial virus B, Metapneumovirus, Coronavirus OC43, Coronavirus 229E, Coronavirus NL63, Rhinovirus, Bocavirus, Enterovirus). All parents of children who tested RSV positive were contacted by telephone by research nurses to complete the follow-up questionnaires. Parents signed an informed consent form before swab collection. The medical ethical committee of OPBG Medical Centre Italy provided a waiver for ethical approval (Prot. N 1301), all methods were performed in accordance with the guidelines for good clinical practice.
The Netherlands
In the Netherlands, the infrastructure of the national routine influenza surveillance network in primary care was used [29]. For the routine surveillance program, 36 GP practices including 55 fulltime equivalent GPs, are asked to swab each week at least one child under the age of 10 years with influenza-like illness (ILI) or another ARI and complete the Day-1 questionnaire. Swabs were sent to RIVM by post and analysed using In-House RT-PCR for 6 viruses (Influenza A, Influenza B, RSV A, RSV B, Rhinovirus, Enterovirus). Among the children participating in the surveillance program, only parents of children under the age of 5 years with a positive RSV test result were asked for informed consent for this study via a letter sent by their GP. The follow-up questionnaires were collected using a digital questionnaire system. As the Day-1 questionnaire was collected as part of the influenza surveillance program in the Netherlands, the questions regarding the medical history of the child were added to the Day-14 questionnaire for practical reasons. The medical ethical committee of VU medical center provided a waiver for ethical approval, all methods were performed in accordance with the guidelines for good clinical practice.