The Financial Burden of Surgery for Congenital Malformations—The Austrian Perspective

Neonatal “surgical” malformations are associated with higher costs than major “non-surgical” birth defects. We aimed to analyze the financial burden on the Austrian health system of five congenital malformations requiring timely postnatal surgery. The database of the Austrian National Public Health Institute for the period from 2002 to 2014 was reviewed. Diagnosis-related group (DRG) points assigned to hospital admissions containing five congenital malformations coded as principal diagnosis (esophageal atresia, duodenal atresia, congenital diaphragmatic hernia, gastroschisis, and omphalocele) were collected and compared to all hospitalizations for other reasons. Out of 3,518,625 total hospitalizations, there were 1664 admissions of patients with the selected malformations. The annual mean number was 128 (SD 17, range 110–175). The mean cost of the congenital malformations per hospital admission expressed in DRG points was 26,588 (range 0–465,772, SD 40,702) and was significantly higher compared to the other hospitalizations (n = 3,516,961; mean DRG 2194, range 0–834,997; SD 6161; p < 0.05). Surgical conditions requiring timely postnatal surgery place a significant financial burden on the healthcare system. The creation of a dedicated national register could allow for better planning of resource allocation, for improving the outcome of affected children, and for optimizing costs.


Introduction
Congenital malformations affect 3% of newborns in the United States and are responsible for 20% of deaths in the first year of life [1][2][3]. Only a limited number of patients born with malformations require timely surgical correction of the malformation after birth. This includes patients with esophageal atresia with or without tracheoesophageal fistula (EA/TEF), duodenal atresia (DA), congenital diaphragmatic hernia (CDH), gastroschisis (GS), and omphalocele (OM). With a prevalence of less than 2 per 2000, all the above-mentioned malformations belong to the group of rare diseases [4]. The European Commission recently established supranational networks of specialists and patients advocates, the so-called European Reference Networks (ERNs), aimed at improving treatment, allocating resources in a targeted way, and promoting research in this field [5].
In order to achieve the best possible outcome, the small number of patients born with congenital malformation require a conspicuous provision of resources, not only for initial treatment, but also for long-term follow-up. Furthermore, the quality of the initial treatment could potentially affect both the patients' future quality of life and the subsequent costs of lifelong care [6]. This relationship is particularly well known for congenital heart Int. J. Environ. Res. Public Health 2021, 18, 11166 2 of 8 diseases. A recent review of the long-term follow-ups of 228 patients revealed the major economic burden of these conditions [7].
It has recently been highlighted that "surgical" malformations are associated with higher costs than major "non-surgical" birth defects. This holds especially true for preterm babies [1]. Furthermore, it is a matter of vivid discussion whether a high volume of patients treated in a single center would ensure a better level of care and, therefore, could impact a patient's outcome [8]. The relationship between high-volume centers, improved outcome, and costs reduction has already been demonstrated for other conditions. A large review including patients with congenital heart malformations has revealed significantly decreased hospital costs and more efficient resource allocation for patients admitted to intensive care units specializing in cardiac care [9]. This centralization also appears necessary to allow for better follow-up and optimal management of complications [10]. Despite the growing interest in understanding the costs of each one of the above-mentioned congenital malformations, data concerning the impact of these diseases on the Austrian health system are lacking [11].
Currently, about 8.8 million people live in Austria and the health system is entrusted to the nine federal states of the Austrian federation. In this territory, seven pediatric surgical departments meet the needs of the majority of the population.
The aim of this study was to analyze the financial burden on the healthcare system of five rare congenital malformations requiring timely postnatal surgery.

Materials and Methods
The database of the Austrian National Public Health Institute (Gesundheit Österreich GmbH, GÖG), an institution responsible for researching and planning public healthcare in Austria, was retrospectively reviewed.
Since 1997, the estimated costs of the Austrian national health system are calculated on the basis of the so-called DRG model (diagnosis-related groups). This system is based on the attribution of points according to standardized parameters at the national level. These include the medical procedures performed, the illnesses found, or the diagnosis coded via ICD-10, the age, and the hospital departments involved. The DRG model represents a powerful tool to standardize the quantification of expended and needed resources. A corresponding value in EUR to a single dataset is, however, not possible [12].
Data about the number of DRG points of each single admission in the general acute care and non-rehabilitation hospitals were collected. Due to a change in the electronic documentation system, data availability with respect to the research question was most adequate in the period from 2002 to 2014. Therefore, the present publication is based on this time frame.
For the present study, we collected the number of DRG points assigned to hospital admissions containing one of the following malformations coded as principal diagnosis: ICD-9-CM Q39.0 or Q39.1 (EA/TEF), Q41.0 (DA), Q79.0 (CDH), Q79.3 (GA) and Q79.2 (OM). These 5 neonatal surgical conditions are usually coded as principal diagnosis exclusively after birth, while in cases of subsequent hospitalizations, the principal diagnosis corresponds to the complication and the primary malformation is coded as secondary diagnosis. For this reason, the number of hospitalizations with the surgical anomaly coded as principal diagnosis roughly reflects the number of patients affected. We did not consider hospitalizations when the malformation did not appear as principal diagnosis.
The DRG points of each hospitalization for the considered anomalies and those of each single hospitalization for any other diagnosis during the period from 2002 to 2014 were collected.
The present study was approved by the local Ethics Committee (EK 33-239 ex 20-21). Statistical analysis was performed using IBM ® SPSS ® Statistics, version 22 (IBM Corp., Armonk, NY, USA). Data are presented as means, ranges and standard deviations (SD). Statistical comparisons of DRG points between congenital malformations and other hospitalizations were performed with a Mann-Whitney U test. Comparison of the DRG points per admission of the five congenital malformations was performed with a Kruskal-Wallis test. Post hoc analysis with Mann-Whitney U tests was conducted with a Bonferroni correction applied. A p-value of <0.05 was considered statistically significant. hospitalizations were performed with a Mann-Whitney U test. Comparison of the DRG points per admission of the five congenital malformations was performed with a Kruskal-Wallis test. Post hoc analysis with Mann-Whitney U tests was conducted with a Bonferroni correction applied. A p-value of <0.05 was considered statistically significant.

Total Hospitalizations
During the 13-year study period, 3

Total Hospitalizations
During      The mean cost per hospital admission expressed in DRG points of the congenital malformations was 26,588 (range 0-465,772, SD 40,702) and was significantly higher compared to the amount of DRG points of all the other hospitalizations together (n = 3,516,961; mean DRG 2194, range 0-834,997; SD 6161; p < 0.05). In detail, GS cost almost 15.61 times more than all other admissions. The burden for the remaining conditions was approximately 13.91 times higher for CDH, 14.97 for OM, 10.50 for DA and 8.82 for EA/TEF respectively ( Table 2). When comparing the DRG points of the five congenital malformations, EA was associated with a significantly lower number of DRG points per admission than DA, CDH, OM and GS (Figure 3a). Over the years, there were no statistically significant changes of DRG points per admission of the five different malformations (Figure 3b).

Congenital Malformations and Comparison to Other Hospitalizations
The DRG points of the five different malformations and the other malformations for the years 2002 to 2014 are presented in Supplementary Table S1.  Supplementary Table S1.

Discussion
With this study, we demonstrated how five different congenital malformations, which usually require timely surgery after birth, influence the budget of the national health system in Austria. In particular, we found costs ranging between 8.82 times higher for esophageal atresia to 15.61 times higher for gastroschisis compared to all other hospitalizations.
Rare diseases are conditions with a prevalence of less than 1 per 2000 [5]. Among others, congenital malformations represent a large part of these diseases [13]. The five congenital malformations included in our analysis have low incidences of 1 out of 2500 newborns for EA, 1-2 out of 10,000 for DA, 1-5 out of 10,000 for CDH, 1 out of 5000 for GS and 1 out of 8500 for OM. Despite their low incidence, it is increasingly recognized that the financial and clinical burden of these congenital malformations is not negligible. Therefore, there is a growing interest to optimize associated costs [14][15][16]. In a recent analysis of the North-Eastern Italian Registry, rare diseases had an overall incidence of 3.85 per 10,000 inhabitants. Among these, pediatric congenital malformations were recognized as a relevant public health issue [17].
In the past, the surgeon acted as the main player in the treatment of these pathologies and surgery was considered the only variable influencing their prognosis. Over the years, however, awareness of the complexity of these malformations has developed and the necessity of diverse and dedicated healthcare professionals to care for these patients has been recognized. The higher costs of admissions for patients with GS, for example, probably reflects the length of the postnatal hospital stay due to the time these patients need for weaning from parenteral nutrition [18]. Furthermore, complex GS in particular can be associated with complications, such as prolonged ileus, sepsis, wound infection, and necrotizing enterocolitis, requiring multiple transfers to the intensive care unit and sometimes even surgical re-interventions. During this long hospitalization, pediatric intensivists, dieticians, nutritionists, gastroenterologists, as well as pediatric surgeons, are indispensable. Therefore, the single operation does not explain the burden of the costs of hospitalization for the different malformations studied.
Furthermore, these anomalies could present with associated anomalies necessitating a multidisciplinary experienced team. If EA is, for example, part of a VACTERL syndrome (vertebral abnormalities, anal atresia, cardiac defects, tracheo-esophageal abnormalities, renal anomalies, and limb abnormalities), other experts beside the pediatric surgeons are

Discussion
With this study, we demonstrated how five different congenital malformations, which usually require timely surgery after birth, influence the budget of the national health system in Austria. In particular, we found costs ranging between 8.82 times higher for esophageal atresia to 15.61 times higher for gastroschisis compared to all other hospitalizations.
Rare diseases are conditions with a prevalence of less than 1 per 2000 [5]. Among others, congenital malformations represent a large part of these diseases [13]. The five congenital malformations included in our analysis have low incidences of 1 out of 2500 newborns for EA, 1-2 out of 10,000 for DA, 1-5 out of 10,000 for CDH, 1 out of 5000 for GS and 1 out of 8500 for OM. Despite their low incidence, it is increasingly recognized that the financial and clinical burden of these congenital malformations is not negligible. Therefore, there is a growing interest to optimize associated costs [14][15][16]. In a recent analysis of the North-Eastern Italian Registry, rare diseases had an overall incidence of 3.85 per 10,000 inhabitants. Among these, pediatric congenital malformations were recognized as a relevant public health issue [17].
In the past, the surgeon acted as the main player in the treatment of these pathologies and surgery was considered the only variable influencing their prognosis. Over the years, however, awareness of the complexity of these malformations has developed and the necessity of diverse and dedicated healthcare professionals to care for these patients has been recognized. The higher costs of admissions for patients with GS, for example, probably reflects the length of the postnatal hospital stay due to the time these patients need for weaning from parenteral nutrition [18]. Furthermore, complex GS in particular can be associated with complications, such as prolonged ileus, sepsis, wound infection, and necrotizing enterocolitis, requiring multiple transfers to the intensive care unit and sometimes even surgical re-interventions. During this long hospitalization, pediatric intensivists, dieticians, nutritionists, gastroenterologists, as well as pediatric surgeons, are indispensable. Therefore, the single operation does not explain the burden of the costs of hospitalization for the different malformations studied.
Furthermore, these anomalies could present with associated anomalies necessitating a multidisciplinary experienced team. If EA is, for example, part of a VACTERL syndrome (vertebral abnormalities, anal atresia, cardiac defects, tracheo-esophageal abnormalities, renal anomalies, and limb abnormalities), other experts beside the pediatric surgeons are desirable for care, including cardiologists, otolaryngologists, orthopedic surgeons, as well as dedicated nursing staff [19].
Our data clearly show the financial impact of these diseases, which requires adequate staff preparation and facility planning. For this reason, centers aiming to treat these patients should have multidisciplinary teams experienced with the specific and multiple problems of these patients [20].
In a recent report, Schmedding and coworkers analyzed the outcome of patients who underwent pediatric surgical treatment for abdominal wall defects in the decentralized care system of Germany. The authors found mortality rates similar to that reported in the literature and deduced that the volume of the center does not influence patient outcome [21]. Nevertheless, other studies including similar conditions have demonstrated the opposite [11,22,23]. In our opinion, mortality as the only parameter for evaluating the effectiveness of the treatment of pathologies with such a degree of complexity is not sufficient. Furthermore, the question arises whether it is justifiable to keep many lowvolume centers rather than allocating resources to optimize high-volume centers.
The referral to centers of reference should ideally take place already in the prenatal period [24]. Prenatal diagnosis of the majority of the five studied malformations is possible. Only EA/TEF often remains unnoticed despite the improvement of diagnostic tools [25]. The high level of experience and competence of reference centers should guarantee a better treatment of patients as well as an optimization of associated costs. Centralization of patients is also essential during long-term follow-up. Dedicated centers can guarantee standardized protocols and the early recognition of complications specific for each malformation [20].
Understanding the financial burden of the studied pathologies is an essential first step in raising the awareness of political and administrative leaders but must be followed by a proposal to improve planning. Therefore, it is of uppermost importance to obtain more accurate information about these pathologies. The creation of dedicated registers allowing the sharing of data concerning all aspects of rare diseases has proven to be the most appropriate start [26]. A structured registry also helps to facilitate the development of dedicated research on the basis of higher numbers, which by definition are lacking on rare diseases. For example, centralized collection of information on gastroschisis patients could be useful in understanding whether the time to achieve full enteral nutrition is different in high-volume versus low-volume centers, thereby allowing stakeholders to ultimately allocate more resources to one center rather than the other. Furthermore, if introduced and guided centrally, it could help to overcome the individualism of single centers. The effort in this direction by the European Union with the creation of the ERNs is evident. This process will foster an integration of experiences and efforts in treatment and research in the field of rare diseases [27].
In our opinion, it is necessary to raise the consciousness of politicians and stakeholders that, despite their low incidence, the examined congenital malformations represent an important part of resource allocation. The examined malformations are rare, but their treatment is costly. Moreover, considering our results, we suggest creating dedicated registers and to implement centers with proved expertise in treating rare conditions in order to facilitate measurement and comparison of outcomes.
Important limitations of our study are the impossibility of correlating the single diagnosis to a specific patient and the non-direct convertibility of the DRG points to a corresponding EUR value. Consequently, it was not possible to correlate these costs with other important indicators, such as the duration of hospitalization, comorbidity, frequency of complications, and mortality. However, the comparison between DRG points invested in different pathologies stratified by year allows an accurate examination of the additional financial burden determined by the considered anomalies. To the best of our knowledge, our data are the first comparing the costs of hospitalizations for congenital malformations to that of all other diagnoses.

Conclusions
The considered congenital malformations requiring timely surgery after birth represent a significant financial burden in Austria. The actual lack of available information prevents improvement in treatment planning for these rare diseases. Therefore, the prospec-