A nationwide study of COVID-19 impact on mental health-related presentations among children and adolescents to primary care practices in Australia


 This study explored the impacts of COVID-19 on the mental health (MH)-related visits to general practices (GPs) among children and young people (CYP) up to 18 years of age in Australia. This study analysed national-level data captured by the NPS MedicineWise program on monthly CYP MH-related visits per 10,000 visits to GPs from January 2014 to September 2021. We considered the pre-COVID-19 period (January 2014–February 2020) and the COVID-19 period (March 2020–September 2021). We used a Bayesian structural time series (BSTS) model to estimate the impact of COVID-19 on MH-related GP visits per 10,000 visits. A total of 103,813 out of 7,690,874 visits to GP (i.e., about 135 per 10,000 visits) were related to MH during study period. The BSTS model showed a significant increase in the overall MH-related visits during COVID-19 period (33%, 95% Credible Interval (Crl) 8.5%–56%), particularly, visits related to depressive disorders (61%, 95% Crl 29%–91%). The greatest increase was observed among females (39%, 95% Crl 12%–64%) and those living in socioeconomically least disadvantaged areas (36%, 95% Crl 1.2–71%). Our findings highlight the need for resources to be directed towards at-risk CYP to improve MH outcomes and reduce health system burden.



Introduction
The COVID-19 pandemic has challenged health care systems worldwide in terms of accessibility and quality of care.Moreover, the social and economic sequelae of COVID-19 have significantly impacted the mental health (MH) and wellbeing of Australians, particularly, children and young people (CYP) (Fisher et al., 2020;Li et al., 2022;Newby et al., 2020).Evidence suggests that CYP have been disproportionately impacted by the social distancing measures, such as social isolation and home confinement (Loades et al., 2020), school closure (Lee, 2020), abrupt familial financial stress such as parental job loss, domestic violence, and abuse (Abramson, 2020;Swedo et al., 2020).It has also been suggested that the unintended consequences of the anti-contagion measures may have acted as a trigger to the occurrence and deterioration of mental stress among children, especially those who had already been exposed to longstanding social and psychological vulnerabilities before the pandemic (Hall et al., 2019;Twenge et al., 2019) and in CYP with developmental disabilities (Masi et al., 2021).Further, studies from across the globe have shown increased levels of depression, anxiety, post-traumatic stress disorder (PTSD), eating disorders, and attention-deficit/hyperactivity disorder (ADHD) among CYP during the pandemic period (Cost et al., 2022;Ravens-Sieberer et al., 2022).
One of the important ways of determining the impact of the pandemic on MH among CYP may come from examining patterns of identification and management of MH problems in the primary health care setting.This is currently an overlooked data source, with many studies instead focusing on emergency department (ED) and hospitalization data.Primary health care is the cornerstone of Australia's health care system (Australian Nursing Federation, 2009;Department of Health, 2013), and it is estimated that 85% of Australians consult a General Practitioner (GP) at least once annually (Australian Institute of Health and Welfare, 2018).Mental Health (MH) disorders such as anxiety and depression are some of the most common presentations to the GP practices (Britt et al., 2016).Furthermore, the 2021 General Practice Health of the Nation survey reported statistically and clinically significant increase in the number of MH-related presentations from 61% in 2017 to over 70% in 2021 (Royal Australasian College of General Practitioners, 2022).Additionally, around half of children aged 4-17 years with a MH disorder, or 80% of those with severe mental illness, seek GP services in Australia (Johnson et al., 2016).However, the trends and the factors influencing increased MH-related presentations among CYP have not been investigated at a national level.
To address this knowledge gap, this study aimed to use a nationally representative dataset of electronic health records (EHRs) extracted from over 500 consenting General Practices (GPs) across Australia between 2014 and 2021 to determine the impact of COVID-19 on the MHrelated primary care presentations among CYP.Furthermore, key sociodemographic factors were ascertained to identify the subgroups of CYP most affected by the pandemic.It is anticipated that the findings from this study will provide insight on the burden associated with MH-related presentations in primary care among CYP and their help seeking behaviours during the pandemic period compared to pre-pandemic periods.This in turn may subsequently inform health service practice, planning, and policy; improve current resource allocation practices; and improve MH outcomes among CYP.

Study design and population
This study analysed national-level data on monthly MH-related visits per 10,000 visits by CYP to general practices in Australia from January 2014 to September 2021.Pre-COVID-19 period was considered as January 2014 to February 2020 and the period of March 2020 to September 2021 as the COVID-19 period.The study population included all CYP up to 18 years of age and who had a GP visit that is clinical, captured in MedicineInsight, a dataset managed by NPS MedicineWise.Visits which did not meet all the criteria were excluded for analysis.More details on the eligibility criteria, data extraction, cohort selection, and identification of MH conditions are provided in Supplementary files A and B.

Data sources
MedicineInsight is a large dataset of General Practice (GP) electronic health records Australia-wide.It is a potential source of a nationally representative sample of GP patients (NPS MedicineWise., 2021).In this study, all CYP up to 18 years of age who had at least one GP visit between 1 July 2020 and 30 June 2021 were identified and selected from a random sample of 1.2 million patients from the from 561 consenting GPs.The dataset contains longitudinal, anonymous patient health records (e.g., demographics, encounters, diagnoses, prescriptions, pathology tests) from the GP clinical information system (CIS) (Busingye et al., 2019).All collection processes have been detailed elsewhere (Busingye et al., 2019).This study was conducted using the staging layer data that has been produced from MedicineInsight, as part of its harmonization with the Observational Medical Outcomes Partnership (OMOP) Common Data Model (CDM) v5.4 (Supplementary file -A).The OMOP-CDM includes a standard representation of health care experiences (such as information related to health care utilization and condition occurrence), as well as common vocabularies for coding clinical concepts that enable consistent application of analyses across multiple disparate data sources.At the time of this study, the OMOP CDM harmonization was not completed; as such the staging layer was used instead of OMOP CDM layer of MedicineInsight.

Ethics approval
This study has been approved by University of New South Wales Human Research Ethics Committee (HREC Reference number: HC210894) under the negligible risk category as the study uses only deidentified aggregated data.Additionally, access to MedicineInsight has been approved its the independent Data Governance Committee (application number: 2021 − 022).

Cohort definition
A MH-related GP visit is identified if the consultation involved a MHrelated diagnosis or reason for prescription or reason for visit or related billing code.Electronic phenotyping algorithms were created to identify individuals who have certain health conditions (Supplementary file A).The CDM-based algorithms are developed based on already existing and validated MedicineInsight's algorithms described elsewhere in further depth.

Analysis
A descriptive analysis was performed to understand the distribution of variables.Exploratory analysis was used to determine the difference in the monthly average MH-related GP visits (total or specific condition) per 10,000 visits between the pre-COVID-19 and COVID-19 periods, where the statistical significance of the difference was estimated using the Wilcoxon rank sum test.A Bayesian structural time series (BSTS) model was employed to estimate the impact of COVID-19 on MH-related GP visits per 10,000 visits.Briefly, impact estimations based on BSTS models required two steps.First, the model was estimated using the data from the pre-COVID-19 period, to produce predictions for the COVID-19 period.The relative difference between the predicted and observed values during the COVID-19 period was interpreted as the impact of the COVID-19 pandemic on MH-related GP visits per 10,000 visits (i.e., posterior relative effect).We calculated the 95% Bayesian credible interval (CrI) to estimate the precision of relative effects, where an effect with a CrI that excludes zero is considered statistically significant.The Markov Chain Monte Carlo (MCMC) technique with 40,000 iterations and a burn-in period of 4000 iterations was used to calculate predicted values and 95% CrI in the Bayesian framework.The analyses were also stratified according to key sociodemographic variables (i.e., sex and residential area socioeconomic status).All analyses were performed using R version 4.1.2.The data was stored and analysed using the cloud based Secure Research Environment for Digital Health (SREDH) platform (https://www.sredhconsortium.org/).

Results
Between January 2014 and September 2021, there were a total of 7690,874 visits to GP by the CYP (aged 0-18 years), of which 103,813 (1.35%) were MH-related.Of these, a substantial amount of MH-related GP visits was observed among adolescents between the ages of 12 up to 18 years (81.2%).Additionally, in terms of gender distribution, females had a slightly higher percentage of MH-related presentations compared to males (53.6% vs 46.2%).Further, CYP from more affluent neighbourhoods (least and second least disadvantaged) had more presentations compared to their counterparts (Table 1).
Average monthly GP visits per 10,000 GP visits for MH issues rose substantially from 78 per 10,000 visits in the pre-COVID period to 221 per 10,000 visits in the COVID-19 period (i.e., nearly 2.8 times) (Table 2).Depressive disorders (6 times), eating disorders (3.3 times), anxiety and obsessive-compulsive disorders (2.9 times), and schizophrenia spectrum disorders (2.4 times) had the highest increases in the average monthly number of GP visits per 10,000 visits.During the COVID-19 period, reaction and adjustment disorders, as well as attention deficit, disruptive, and impulse control disorders, had more than twofold increase in the average monthly GP visits per 10,000 visits.
Figs. 1 and 2 show observed and forecasted numbers of MH-related GP visits per 10,000 visits and their difference by month, respectively, during the study period.The model-based results show that the posterior relative effect of the COVID-19 led to a 26% increase in MH-related GP visits per 10,000 visits (95%Crl 8.8% to 40%).Females (39%, 95%Crl 12%, 64%) and CYP from wealthy neighbourhoods (36%, 95%Crl 1.2%, 71%, least disadvantaged regions) made significantly more GP visits for MH issues (Table 3).Specifically, a statistically significant increase was noticed in visits related to depressive disorders (61%, 95%Crl 29%, 91%).Eating disorders, schizophrenia spectrum disorders, and anxiety and obsessive-compulsive disorders also observed a notable increase in GP visits, though they were not statistically significant (Table 3).

Discussion
To the best of our knowledge, this is the first study to examine the impact of the COVID-19 pandemic on MH-related primary care service use among CYP in Australia.Findings of this nationwide study indicate a substantial increase in the overall MH-related GP visits among the CYP in Australia during the COVID-19 period.Of note, is the significant increase in the rates of depression during the COVID-19 pandemic compared with the pre-COVID-19 period.Further, the increase in MHrelated visits during the pandemic was significantly higher for females compared to males and those living in socioeconomically less disadvantaged areas compared to their counterparts.
Contrary to other studies which have reported reduction in MHrelated primary care use during the COVID-19 period (Carr et al., 2021), our study has shown that MH consultations increased by 33% in the COVID-19 period for CYP when compared to the pre-COVID-19 period.This increasing pattern during pandemic years is corroborated by a Norwegian study which found a gradual increase in the number of primary consultations linked to MH during Fall 2020 and continuing through 2021 (i.e., the second and third waves of pandemic) among CYP aged 6-19 years (Evensen et al., 2022).A US study also observed an increase in the overall primary care encounter volume, of which MH was the most commonly reported problem, with higher amount of telemedicine encounters and fewer in-person visits (Schweiberger et al., 2020).The increase in visits may also be attributable to Australian GPs being more likely to be comfortable with diagnosing and recording mental health conditions in childrenparticularly given the introduction of MH specific telehealth items during the pandemic.Besides the primary care setting, the increase in MH-related presentations among CYP was reflected across other health care settings, where our study showed a 16% increase in MH-related ED presentations among CYP during the COVID period (Khan et al., 2023).
Although the increase in MH-related GP presentations was observed in both genders, it was more pronounced in females (25% increase among males vs 39% increase among females).This finding is consistent with population-based studies in Canada and Korea which found a significant increase in MH-related physician-based outpatient visits during the COVID-19 pandemic, particularly among adolescent females (Kim et al., 2022;Saunders et al., 2022).This finding suggests that female CYP were disproportionately affected and were more vulnerable to the psychological effects of the pandemic.This is supported by other studies reporting higher rates of depression and anxiety during puberty, particularly among girls (Kauhanen et al., 2023;Knight et al., 2021).A review (and this study) showed that the COVID period was associated    with worsening rates of eating disorders which are much more common in females (Sideli et al., 2021).We also found an increased MH-related primary care use among CYP from affluent neighbourhood compared to disadvantaged areas.This is consistent with a Danish nationwide study (Packness et al., 2021), which found that people from a higher socioeconomic position (SEP) were more likely to avail the use of health services such as GP services for MH-related problems compared to those from a lower SEP, which may be compounded with other factors such as higher level of education, private insurance, and being more aware of telehealth services.Further, our work has highlighted an inequity in access to health services via an inverse care law in that those CYP with the greatest MH needs from the most disadvantaged backgrounds being least likely to access health services early and they often present only after complexities and comorbidities have set in (Eapen et al., 2023).This is due to systemic barriers including financial, structural, cultural/linguistic and technological barriers in service access, further compounded by lockdown related restrictions during Covid-19 (Eapen et al., 2021).While the aggregate data provides insights into population-level correlations, it is important to note that the higher volume of visits from females in affluent areas does not provide a definitive explanation.It is unclear whether this pattern is primarily driven by resource availability or specific factors related to diagnoses such as previous mental health history, comorbidities, latency and transitory nature of symptoms, and timing of diagnosis.However, the available data does offer some indications regarding the factors associated with the distribution of mental healthcare service utilization.
This study also found differences based on the type of MH diagnosis with significant increase in depression.In this regard, a Norwegian study found a 38% increase in overall primary care MH consultations among adolescents with a 52.4% increase for depression and anxiety which was also more pronounced among girls (Evensen et al., 2022).An Icelandic study utilizing self-reported sadness found a rise in depressive symptoms among teenagers aged 13 to 18 years during the pandemic (Thorisdottir et al., 2021).During the onset of the pandemic, both children's use of social media and their exposure to pandemic-related online contents increased, which has been linked to elevated levels of depression, anxiety, and psychological distress (Guessoum et al., 2020).In another study, adolescents in Australia reported higher levels of depression and anxiety, as well as lower levels of life satisfaction, during COVID-19 compared to the pre-COVID-19 period.Concerns about COVID-19, changes in their learning, and conflicts with their parents all contributed to this trend (Magson et al., 2021).Although our study found a notable increase in the MH presentations related to anxiety, obsessive compulsive disorders, eating disorder, and schizophrenia, the model-based findings were not statistically significant, but may still have clinical significance.Further, our study did not find any increase in PTSD presentations which may be attributed to the common issue of underdiagnosing patients, particularly CYP with PTSD in primary care as it is often comorbid with or overshadowed by other MH conditions (Meltzer et al., 2012).Notably, the finding of an increase in eating disorder presentations during the pandemic is consistent with other studies (Bittner Gould et al., 2022;Zipfel et al., 2022).Several potential reasons have been described for the increase including daily routine disruptions, lack of access to outdoor activities, increasing concern about weight gain, reduction in the availability of supports due to social isolation and increased stress and fear of contagion as well as anxiety-provoking media (Rodgers et al., 2020).
This study has several strengths and limitations.This is the first study in Australia to determine the nationwide impact of COVID-19 on CYP's MH-related utilization of primary care services.Additionally, findings of this study are generalisable as it is based on a large sample from a large dataset with 561 participating GP practices, covering all of Australia's states and regions, along with a wide range of primary care practises that differ in terms of their size, billing practices, and services provided.A significant additional strength of the study is the use of a BSTS model, which allows for more flexibility in inferring counterfactuals, temporal variation, and incremental effect.Nonetheless, some limitations need acknowledging.The causal relationship between increased GP visits and the COVID-19 pandemic cannot be fully addressed by the current study design partly due to unavailable confounders (e.g., household environment, parental MH issues, etc.).This study was not able to address the biases arising from availability heuristics given the increased investment in mental health and in telehealth services by the Australian Government and whether this increased availability may have led to increase in presentations rather than actual increase in mental health issues.However, our study of a national sample of hospital admissions and Emergency Room presentations across Australia has also found a similar increase in overall presentations by up to 60% and in particular, 75% increase in presentations for eating disorders (Khan et al., 2023).This suggests that the increase may be a true trend.While it is difficult to be definitive about the reasons for such increase in MH presentations, it is possible that school closures, social isolation, restriction of movement, family stress etc. may have been contributed to this.Directions for future study could employ using linked claims data to verify the increase in trends.Additionally, further research is also necessary to determine whether this increasing pattern persists during and beyond the COVID-19 restriction-easing period and how any deterioration in the MH of CYP can be mitigated.

Conclusion
Although recent studies have generated inconsistent evidence for the increased rates of MH care needs during the pandemic, findings of this study suggest an increase in GP presentations for MH-related disorders in CYP.Our findings also showed a significant increase in GP presentations for depression and more pronounced among females CYP and those living in socioeconomically least disadvantaged areas.Although lower levels of comorbidity and mortality associated with COVID-19 have been observed in CYP than in adults, anti-contagion measures could have had a direct impact due to reduced access to school-related resources, which in turn might have posed some additional challenges in the context of pre-existing or new psychiatric and neurodevelopmental issues (Lin et al., 2021).Whilst it remains unclear whether this trend in response to the pandemic stems from the increased distress in the population, this study indicates the need to revisit the resources for MH care services for CYP in the post-pandemic reset of services.Monitoring the longer-term effect of the pandemic on MH conditions of CYP is critically needed for service planning including prevention and intervention strategies.

Data availability Statement
Data is available upon formal request to the Quality Use of Medicines (QUM) Program of the Australian Commission on Safety and Quality in Health Care.

Table 2
Percentage increase in the monthly average (pre-COVID vs COVID) and estimated effects of the COVID-19 pandemic on mental health-related GP visits per 10,000 GP visits.

Table 3
Estimated effects of the COVID-19 pandemic on all mental health-related GP visits by sex and residential area socioeconomic status.Credible interval; *statistical significance (p-value <0.05).Note: A stratified analysis by age group was not performed due to the small number of MH-related visits among children 0-8 years old.