On 11 March 2020, the WHO (World Health Organization, 2020) declared a global pandemic of COVID-19 which enforced many countries to introduce generic infection control measures such as wearing face masks, hand washing, social distancing, working from home and closure of schools/daycare centers. Other than reducing SARS-CoV-2 transmission, these generic measures have likely affected transmission of other respiratory viruses (Fricke et al., 2021; Tang et al., 2021). Since otitis media (OM) is generally preceded by a viral upper respiratory tract infection (URTI) (Schilder et al., 2016), changes in transmission dynamics of these viruses may have had an impact on the incidence of OM. OM, one of the commonest conditions during early childhood and a prime reason for antibiotic prescriptions (Klein, 2000; Monasta et al., 2012; van den Broek d’Obrenan et al., 2014; Tong et al., 2018), consists of a spectrum of diseases, including acute otitis media (AOM), otitis media with effusion (OME), and chronic suppurative otitis media (CSOM). AOM is characterized by the presence of middle ear effusion (MEE) with rapid onset of signs and symptoms of an acute infection such as fever and ear pain (Lieberthal et al., 2013). Approximately 15%-20% of children with AOM present with ear discharge due to a spontaneous tear or perforation of the eardrum (Rovers et al., 2006; Smith et al., 2010). OME is defined by the presence MEE, without signs and symptoms of an acute infection (Rosenfeld et al., 2016). Hearing loss is the most common symptom of OME. CSOM is characterized by chronic inflammation of the middle ear and mastoid mucosa together with a non-intact tympanic membrane and persisting ear discharge (Verhoeff et al., 2006). Several reports from the early phase of the COVID-19 pandemic have suggested a decline in doctor consultations for OM in children (Hatoun et al., 2020; Aldè et al., 2021; Angoulvant et al., 2021; Iannella et al., 2021; Kaur et al., 2021; Torretta et al., 2021; van de Pol et al., 2021). The question is whether the infection control measures or the sudden COVID-19 related changes in health care access and delivery are responsible for these changes. We will address this question by investigating the effect of the COVID-19 pandemic on OM consultations and associated antibiotic prescribing in children in a large primary care cohort in the Netherlands where the general practitioner (GP) is the first point of call (Grobbee et al., 2005) for the management of OM for all children and practices could be contacted for medical advice throughout the pandemic.

This large retrospective cohort study showed that GP consultation for AOM, OME and ear discharge declined by 63%, 57% and 54% respectively in the Netherlands during the COVID-19 pandemic.

Previous studies in other countries have reported a similar trend in childhood OM incidence during the first COVID-19 peak (Hatoun et al., 2020; Aldè et al., 2021; Angoulvant et al., 2021; Iannella et al., 2021; Torretta et al., 2021). Under normal circumstances, OM typically shows a seasonal pattern with a winter peak coinciding with the increase in URTI incidence (Castagno and Lavinsky, 2002). Our study demonstrates the absence of the usual winter peak in AOM and OME during COVID-19 which is comparable with the reports of bronchiolitis from Belgium (Van Brusselen et al., 2021). The observed reduction in childhood OM might be attributed to the generic infection control measures, or changes in health care access and delivery. Although primary care services in the Netherlands remained accessible during the pandemic, the measures could have led to a higher threshold for consulting the GP, particularly early in the pandemic.

We found no evidence of an increase in the proportion of childhood OM episodes treated with antibiotics despite a substantial reduction in GP consultations for OM. This suggests that the observed decline in doctor consultations for OM was not related to OM severity and therefore not primarily attributed to a higher threshold to consultation. In line with our findings, a previous study in Scotland reported that the COVID-19 lockdown led to a decline in pediatric emergency care consultations without an associated increase in severity (Williams et al., 2021). Another recent study in the United States has also found a lower rate in respiratory infection visits around September 2020 likely attributed to the infection control measures.

The major strengths of our study are its large sample size using well-documented electronic routine primary care-based health care data. The longitudinal nature of our study allowed us to compare the same study population within the same practices during two full years, i.e. one full year pre-COVID-19 and a complete year during the COVID-19 pandemic. Some methodological limitations need to be considered. First, misclassification might have occurred. Particularly during the COVID-19 pandemic, a substantial proportion of OM diagnoses were based on telephone consultation only which could have led to misclassification in OM diagnosis. A previous study from our group found that only 50% of parent-reported OM (fever and ear pain) episodes led to a GP diagnosis of OM (Fortanier et al., 2015).However, despite the increase in telephone consultations, we found a decline in the ICPC code ‘ear pain’ as well. This suggests that our observations reflect a true decline of OM during the pandemic. Moreover, misclassification might have occurred for the ICPC code ‘ear discharge’ since we were unable to determine whether this related to an acute onset of ear discharge or chronic suppurative otitis media. Furthermore, some children presenting with AOM and ear discharge will likely be classified by their GP as ‘AOM’ [ICPC code H71], i.e. those with AOM who were prescribed topical antibiotics. Second, we were unable to reliably extract data on specialist referrals and data about out of hours primary care were not available. Therefore, our results regarding complications should be interpreted with caution. Reassuringly, a previous study from Italy did not find a significant difference in OM-related complications during the first COVID-19 wave (Torretta et al., 2021) Finally, we were not able to link reductions in childhood AOM episodes to changes in causative viruses and bacteria over time. Such data would have allowed us to better explain our observations.

GP consultation for AOM, OME and ear discharge declined by 63%, 57% and 54% respectively in the Netherlands during the COVID-19 pandemic. Similar antibiotic prescription rates before and during the pandemic indicate that the case-mix presenting to primary care did not change considerably. Our data therefore suggests a true decline as a consequence of infection control measures introduced during the pandemic.

The data analyzed in this study is subject to the following licenses/restrictions: Data are not publicly available due to ethical and legal restrictions. Requests to access these datasets should be directed to not applicable.

Ethical review and approval was not required for the study on human participants in accordance with the local legislation and institutional requirements. Written informed consent from the participants’ legal guardian/next of kin was not required to participate in this study in accordance with the national legislation and the institutional requirements.

Conceptualization AS, RV, and SH. Methodology, RV, SH, AP, and AV. Formal analysis, SH. Resources, RD. Writing— original draft preparation, all authors. Writing—review and editing, all authors. Visualization, SH. All authors have read and agreed to the published version of the manuscript.

This work is supported by a research grant from the Netherlands Organisation for Health Research and Development (ZonMw) [Rational Pharmacotherapy 5th Open Call grant number 84801 5006]. The funder has no role in design, conduct and report this study.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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