Investigating the scope and costs of dental treatment provided under general anaesthesia among children with congenital heart disease

To identify the types of dental treatment provided under general anaesthesia for children diagnosed with congenital heart disease (CHD), quantify the costs within a publicly funded tertiary paediatric hospital setting and identify factors which affect the cost.

1 Children diagnosed with congenital heart disease (CHD) are more prone to developing dental caries compared to unaffected children. 2 Children with chronic illnesses, such as CHD, often require dental treatment under general anaesthesia.
What this paper adds 1 Many children with CHD requiring dental treatment under general anaesthesia presented with dental infections and the majority required dental extractions. 2 Children with CHD often require overnight hospitalisation to provide dental treatment, a parameter strongly correlated to the cost of the general anaesthetic procedure. 3 Children with CHD were mostly referred to the dental department by dental professionals.
Congenital heart disease (CHD) is the most common congenital abnormality among children, affecting over 8 in 1000 live births. 1 Each year in Australia, over 2000 babies are born with CHD. 2 With advances in diagnosis and management, the prevalence and survival of children with CHD are increasing. 1 Dental caries in the primary dentition is the 12th most prevalent disease, with 560 million children affected world-wide. 3 In Australia, 34.3% of children aged 5-6 have experienced dental caries in their primary dentition and 27.1% of children aged 5-10 have untreated disease. 4 In 2015-2016, dental causes accounted for 70 000 potentially preventable hospitalisations. 4 In the 5-to 9-year age group in New South Wales, dental conditions were by far the highest cause of preventable hospitalisations, surpassing both asthma and ear, nose and throat infections. 5 Existing literature has established that children with CHD have poorer oral health compared to unaffected children, in terms of both an overall greater dental caries experience 6 and a greater proportion of untreated dental caries, particularly in the primary dentition. 7 Dental caries risk factors that are unique to the paediatric CHD population include the long-term use of potentially cariogenic cardiac medications, unfavourable oral hygiene practices, unique dietary regimens and a higher reported incidence of developmental defects of enamel. 6 The consequences of poor oral health in children with CHD are considerable. Infective endocarditis is a potentially fatal complication for those that are susceptible. Poor oral health and invasive dental procedures have been implicated as risk factors. 8 Active dental disease may result in the cancellation of life-saving cardiac surgeries. 9 There are challenges in providing timely dental care for children with CHD, such as competing medical priorities, dental anxiety 10 and a lack of parental knowledge regarding the link between oral and cardiac health. 11 In contrast to the general population, comprehensive dental treatment for medically compromised children, such as those with CHD, often requires a procedure under general anaesthesia 12 within a specialised tertiary facility. 13 There are adverse health outcomes for children with CHD undergoing non-cardiac surgeries, including a higher morbidity and mortality associated with general anaesthesia compared to children without major comorbidities. 14 In addition, the potential psychological burden of additional, non-cardiac hospitalisations for children with CHD cannot be underestimated. 15 Treatment philosophies are centred around definitive care, favouring extractions of teeth significantly impacted by dental caries. 16 As well as the biological impact of poor oral health for children with CHD, there are substantial financial costs associated with dental general anaesthetic procedures. 13 The aims of this study were to identify the most common types of treatments provided during dental general anaesthesia (DGA), quantify the average total cost of DGA for children with CHD within a publicly funded tertiary paediatric hospital setting and identify factors which affected the cost of DGA.

Methods
A retrospective analysis drawing from four years of medical and dental records (1 July 2015 to 30 June 2019) at The Children's Hospital at Westmead (CHW) in New South Wales, Australia was undertaken. The sample population was comprised of children with CHD who received at least one DGA at CHW during the study period. Children with CHD were defined as those aged less than 18 years who received surgical intervention/s (cardiac surgery and/or interventional cardiac catheterisation procedures) within The Heart Centre for Children, CHW. Patients diagnosed with isolated cardiac arrhythmias and acquired heart diseases were excluded. DGAs were excluded when another medical procedure was simultaneously conducted, as it was not possible to separate the costs of the DGA.
CHD diagnosis was categorised into three groups (mild, moderate and severe), based on the classification system used by Oliver et al. 17 Comorbidities were defined as non-cardiac conditions that were most likely to impact the clinical decision to perform a DGA. Electronic and paper-based medical and dental records were retrieved for each patient. Information related to patient demographics, medical history, dental history, referral information, dental treatment provided under DGA and the length of admission was collected. The presence of dental caries was determined from dental charting records. Costing data and the definitions for direct and indirect costs were provided by a costing and analysis manager at the Management Support and Analysis Unit, The Sydney Children's Hospitals Network. The total cost of each DGA was calculated as a sum of direct costs, indirect costs, emergency department (ED) costs and preanaesthetic consultation (PAC) costs. Direct costs included dental, anaesthetic, recovery and pharmacy services. Indirect costs included costs that could not be easily linked to a cost object or for which the costs of tracking this outweigh the benefits. Common indirect costs include overhead costs such as salaries of staff in corporate (e.g. finance and human resources) and technical support (e.g. legal) areas, or accommodation costs (e.g. rent, maintenance and utilities). Indirect costs in this study did not include costs incurred by the family or society as a result of missed school and work productivity, transport or childcare-related costs. ED costs were applicable when the patient presented via ED and required subsequent admission and DGA for their dental problem. Patients who are medically compromised and require a procedure under GA may require a PAC visit, at the discretion of the anaesthetic team. This may be done at a separate visit (if time and logistics permit) or on the day of the GA. The patient may or may not be seen by the anaesthetist depending on the complexity of their medical condition and/or the proposed procedure. This data were captured separately as it was an additional cost and resource utilisation for the public hospital and not routinely required for children unaffected by CHD undergoing DGA. Costs were stated in Australian dollars (AUD) and one outlier was removed from the costing-related analyses, as described below.
The data are presented as frequency and percentage to enable comparisons between groups. Quantitative analyses were undertaken using Microsoft Excel, Orange v3.28 and SPSS v25 (IBM, Australia) computer programs. This study computed differences between two groups using an Independent T test and between three or more groups using a one-way analysis of variance. Pearson's correlation coefficient for continuous variables and Spearman's Rho for categorical variables were used to determine relationships between variables. The level of significance was set at P < 0.05.

Ethics statement
Ethics approval was obtained from The Sydney Children's Hospitals Network Human Research Ethics Committee (HREC Reference: 2020/ETH00283).

Results
The dental and medical records of 88 patients (47 males and 41 females) diagnosed with CHD who had at least one DGA at CHW were included in the study. Of these 88 patients, 86 patients had one DGA and two patients had two DGAs during the study period. The mean age at DGA was 8.15 years (SD 3.69, range: 1.42-16.42 years). The severity of the underlying cardiac diagnoses were 52%, 21% and 27% for mild, moderate and severe CHD, respectively, and 51% of patients had a comorbidity. Trisomy 21 was the most commonly occurring comorbid condition, diagnosed in 10 patients.
Regarding the dental history of the study population, 65 (74%) patients had previously visited a dentist, 11 (12.5%) patients had never visited a dentist and no dental history was recorded for 12 (14%) patients. A previous DGA was mentioned in the dental history of 21 (32%) patients.
At the time of DGA, 84% of patients had dental caries. Of the patients who had primary teeth present at the time of the DGA consultation, 80% had dental caries affecting their primary dentition. Of the patients who had permanent teeth present at the time of the DGA consultation, 40% had dental caries affecting their permanent dentition. More than a quarter of the study population (27%) presented either with a history of dental infection or had an active infection upon clinical or radiographic examination.
Dental extractions were performed in 77 of the 90 DGAs (86%), with a mean of three teeth extracted per DGA. A total of 1291 dental services were performed across the 90 DGAs. Diagnostics (predominantly radiographs) made up the majority of services provided under GA (425, 33%), followed by opportunistic preventive services such as fissure sealants, scaling and topical fluoride applications (354, 27%). When diagnostic and preventive services were excluded and only dental interventions were considered, a total of 512 services were performed. Simple dental extractions made up the majority of the total interventions (271, 53%), followed by dental restorations such as fillings and crowns (224, 44%). The remaining interventions comprised of oral surgery, endodontic and periodontic procedures (total 17, 3%). Excluding preventive and diagnostic services, each patient had a mean of 5.7 teeth treated under DGA. Sixty patients (67%) received intra-operative antibiotic prophylaxis for the prevention of infective endocarditis. Two patients were already on intravenous antibiotics at the time of the DGA, secondary to an acute facial swelling.
A costing-related analysis was performed on 89 DGAs ( Table 1). The mean total cost of DGA was $4395.14 AUD (SD $1457.80). One outlier was removed from the costing analysis as the patient spent 21 days in hospital following the DGA and the total cost of their admission was $103 298.40 AUD. The patient had a background of chromosomal anomaly with associated mild CHD. Their innocuous dental treatment involved extractions of non-carious retained primary teeth and resulted in an unplanned readmission to the Paediatric Intensive Care Unit with respiratory failure, seizures and possible sepsis.
The mean number of days spent in hospital, excluding the outlier, was 1.43 days (SD 0.67, range 1-5 days). About 37% of patients spent more than 1 day in hospital. Days spent in hospital showed a strong significant correlation to the total cost of DGA (r = 0.76, P < 0.001). Those who were hospitalised overnight had significantly more teeth extracted (mean 4.21 teeth) than those who were discharged on the same day (mean 2.32 teeth; P = 0.017). There was a significant effect of the reason for referral/attendance on the total cost of DGA (P = 0.009). Patients who presented with an acute facial swelling incurred greater costs (mean $6303.09, SD $1640.93) than patients who presented for a check-up (mean $4438.77, SD $1201.95), chronic dental disease (mean $4247.56, SD $1359.79) or other (noncaries related) reasons (mean $4220.99, SD $1246.91). Patients who had a history of dental infection differed significantly (P = 0.044) from patients without a history of dental infection with the former having greater costs (mean $4965.28, SD $1609) than the latter (mean $4197.37, SD $1331.84).

Discussion
Since children are increasingly surviving their cardiac diagnoses, 1 they are more likely to become susceptible to common chronic diseases, such as dental caries. Children with CHD often require dental treatment under general anaesthesia for a variety of reasons including young age, presence of comorbidities, 18 dental anxiety 10 and extensive or invasive procedures such as dental extractions. Logistically, there may be a preference to provide comprehensive treatment in a single visit if there are pending cardiac surgeries or for those who require antibiotic prophylaxis for infective endocarditis. This is the first Australian study to quantify the financial burden of dental diseases requiring treatment under general anaesthesia in a cohort of children diagnosed with CHD, within a public paediatric hospital setting. Extractions comprised the majority of dental interventions undertaken during DGA. Extractions were necessary in 86% of DGAs. Medical complexity in children with chronic conditions influence the dental treatment provided under GA. Extractions are preferred when there is any doubt about the success of a particular treatment, since sepsis associated with a failed dental restoration could be life-threatening, compared to a similar failure in a healthy child. 19 As expected, there were almost no endodontic procedures provided to children with CHD. These procedures are generally contraindicated in children with CHD who require antibiotic prophylaxis for infective endocarditis, 20 due to the risk that endodontically treated teeth may become potential reservoirs of infection. Over a quarter of children with CHD had a history of dental infection, an especially troubling finding given the majority of the study cohort was considered at risk of infective endocarditis and required antibiotic prophylaxis during their DGA.
The average cost of DGA per patient was $4395.14 AUD. For the general childhood population, the average direct cost for the most common DGA (dental extractions and restorations) was $3029 AUD in public hospitals in 2012/2013. 21 The possible reasons for the apparent greater cost of DGA for children with CHD may be explained by the necessity to provide an increased number of dental services, secondary to a greater burden of dental disease borne by children with CHD. 6,7 Additionally, as this study has shown, patients with CHD are more likely to require overnight hospitalisation compared to unaffected children, who generally do not require overnight hospitalisation following DGA. 22 DGA costs were found to be influenced by multiple factors including the indication for referral and the days spent in hospital. Patients who presented with an acute facial swelling incurred greater DGA costs than patients who were referred for any other reason. This was an expected finding since facial swellings may be considered a medical emergency, especially for patients who are medically compromised and patients often present via the emergency department, incurring additional costs. Overnight hospitalisation may be indicated for adjunctive intravenous antibiotic therapy.
The limitations of this study include the retrospective study design and lack of an age-and sex-matched control group, who required DGA but did not have CHD. We also did not compare the DGA experiences of children with CHD with children who had other chronic health conditions. The lack of these control groups limits our ability to assess the impact of CHD per se on the study outcomes. Children with severe CHD were over-represented in the sample and therefore the findings of this study may not be relevant to those patients with less severe CHD. Onefifth of children with CHD underwent joint medical and dental procedures while under general anaesthesia and were excluded from our study, which may have underestimated our findings.
The overwhelming majority of children with CHD were referred for a dental assessment by professionals outside of their primary cardiac teams. This finding highlights a future research opportunity and overall aim towards timely, streamlined referral pathways to become gold standard care for children with CHD.

Conclusions
Children with CHD bear a substantial amount of dental caries that often requires treatment under general anaesthesia within a paediatric tertiary hospital facility. Not only is there an economic impact of a reactive approach to managing dental disease, the findings of this study also illustrate poor overall health outcomes for these patients since dental extractions are performed in the majority of DGAs. A considerable proportion of children with CHD undergoing a DGA required overnight hospitalisation and days spent in hospital is a strong predictor of the cost of the DGA. The cost of the DGA was significantly greater when children presented with a facial swelling compared to any other reason. This study reminds all professionals involved in the care of children with CHD to ensure their dental health is prioritised early on in their medical journeys. There exists an opportunity to provide holistic, preventive dental education and care for children with CHD, between medical and dental care providers. The goal of this unique interprofessional collaboration is to potentially improve the general health and well-being of paediatric cardiac patients as well as minimise the economic burden of dental diseases on the public health system.