Insurance status is an important indicator of a patient’s access to routine healthcare and health surveillance. Patients with publicly funded insurance, such as Medicaid, have been shown to have significant barriers to care, including transportation issues [1] and work or caregiving conflicts, which have been further associated with less access to high-volume hospitals with specialty surgical care [2] and presenting with more advanced disease progression [3]. In addition, publicly insured patients have been found to participate in fewer scheduled office visits compared to privately insured patients [4] and subsequently requiring increased emergency care [4].

Lack of access and engagement in the healthcare system can be especially critical in certain disease processes, where mismanagement or failure to seek care at an optimal time can significantly impact operative conditions and postoperative outcomes. Ventral hernias, for example, may become incarcerated or strangulated resulting in the need for emergent laparotomies with and without bowel resections. Previous studies have found insurance status to be an independent predictor of emergency repair [5]. Publicly insured patients undergoing emergent repair have also been found to have delayed time to care from admission to surgery, indicating that disparities may exist even when these patients finally present for care [6]. Studies have also found public insurance to be associated with increased odds of non-elective admission, as well as worse postoperative outcomes following VHR [7].

However, these associations have been limited to administrative data sources [5,6,7,8] and have not been explored in a hernia-specific dataset that provides access to more granular details of hernia morphology and operative characteristics. Previous studies have also not been able to specifically elucidate the relationship between public insurance and emergency department (ED) utilization in the immediate postoperative period for patients undergoing VHR. In this study, we seek to investigate the role of insurance payer type on unplanned ED visits within 30 days of VHR, as well as important postoperative outcomes including postoperative complications and readmission among patients undergoing ventral hernia repair in a hernia-specific national dataset.

Methods

Design overview

For this study, a retrospective review was performed on data collected prospectively through the Abdominal Core Health Quality Collaborative (ACHQC). Patients who underwent ventral hernia repair (VHR) were separated into three distinct study groups based on their insurance type: private, Medicaid, and self-pay. Clinical characteristics and postoperative outcomes were assessed for each group, and multivariate regression was employed to identify factors associated with each outcome of interest. Institutional Review Board (IRB) approval was obtained prior to the start of the study and a data use agreement was executed with the ACHQC before accessing data.

Study population and data source

The Abdominal Core Health Quality Collaborative (ACHQC) is a national registry of hernia patients including more than 400 surgical providers across the USA and representing academic medical centers, community health centers, and private practice. Standard definitions are used throughout the registry to ensure data integrity, which have been previously reported. To perform this study, the ACHQC database was queried for all patients aged 18–65 undergoing ventral hernia repair (VHR) between 2013 and 2020. All hernia types and surgical approaches were included. Patients were excluded if they did not have insurance payer-type data available.

Comparison groups

Using insurance payer type, the sample was then divided into three distinct comparison groups. These included private insurance (commercially insured), public insurance (Medicaid insurance), and uninsured (self-pay). All other insurance payer types, including Medicare, Tricare, VA, and workers compensation, were excluded for the purpose of this study.

Outcome measures

The primary outcome of interest in this study was unplanned ED visit within 30 days of surgery. Secondary outcomes of interest included any postoperative complication and readmission. Postoperative complications included surgical site infection (SSI), surgical site occurrence (SSO), as well as urinary tract infections (UTI), deep vein thrombosis (DVT), pulmonary embolism (PE), dehiscence, progressive renal insufficiency, bleeding requiring transfusion, pneumonia, unplanned reintubation, postoperative ventilator use, renal failure, stroke, cardiac arrest, myocardial infarction (MI), and sepsis/septic shock.

Data analysis

Demographic and clinical characteristics were compared by insurance type using Chi-Square and Kruskal–Wallis tests. Unadjusted univariate results were reported for each outcome of interest by insurance type. Multivariate logistic regression was then used to test the association of insurance type with experiencing any postoperative outcome within 30 days of surgery. Regression models were also used to determine the association of insurance type with unplanned emergency department (ED) visit and readmission within 30 days of surgery. Models controlled age, sex, race, smoking status, diabetes, hypertension, emergent presentation, ASA class, and operative approach.

Statistical significance was determined with an alpha value of 0.05. All statistical analyses were performed using SAS enterprise guide v7.1.

Results

The study sample included 17,036 patients who underwent ventral hernia repair. Private insurance was the largest group (85.8%), followed by public insurance (8.4%) and self-pay (5.8%). The study population was majority male and white, with public insurance representing the greatest proportion of female and minority race patients (Table 1). Publicly insured patients were the youngest and had the highest comorbidity burden of all groups (Table 1). Major depression and anxiety disorders, as well as recent opioid use, were also most prevalent among those publicly insured. The majority of the sample underwent elective repair, with nearly one quarter of repairs performed for a recurrent hernia. Repairs were performed in open (64.1%), robotic (19.2%), and laparoscopic (12.7%) approaches and were not significantly different between groups (Table 2).

Table 1 Demographics by insurance type
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Table 2 Operative characteristics by insurance type
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Univariate results

Publicly insured patients demonstrated the highest rate of ED utilization after surgery at 9.3% (p < 0.01). (Table 3). Postoperative complications and readmission were also significantly more common among publicly insured patients (Table 3).

Table 3 Univariate 30-day postoperative outcomes by insurance type
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Multivariable results—primary outcome (ED visits)

Multivariable analysis demonstrated that unplanned ED visits within 30 days were significantly more common among patients with public insurance, with this group exhibiting 70% greater odds of returning to the ED as patients who were privately insured (Table 4). Similarly, patients who were self-pay exhibited 1.6 times greater odds of experiencing an unplanned ED visit. Other predictors of ED visits included postoperative complications, black race, female sex, tobacco use, and mesh repairs (Table 4).

Table 4 Logistic regression model for unplanned ED visit within 30 days
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Multivariable results—secondary outcomes (complications and readmissions)

Multivariable analyses found that publicly insured and self-pay patients had significantly greater odds of experiencing any postoperative complication compared to privately insured patients (Table 5). Similar results were identified in terms of readmission, with publicly insured and self-pay exhibiting 1.54 and 1.82 times greater odds of being readmitted, respectively (Table 6).

Table 5 Logistic regression model for any postoperative complication within 30 days
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Table 6 Logistic regression model for readmission within 30 days
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Discussion

This study found that publically insured/low socioeconomic status (L-SES) patients have higher rates of adverse events, including ED visits, complications, and readmission after ventral hernia repair. This is consistent with other studies which have shown that publicly insured patients have worse outcomes after hernia repair [5, 7,8,9]. This study was unique in including patients who were uninsured in direct comparison to private and public insurance groups. Furthermore, this is the first study to describe differences in unplanned postoperative ED visit rates. Improving outcomes in this group represents a significant opportunity to address care disparities and potentially save costs that are conferred by ED visits and readmissions.

Publicly insured/L-SES patients have higher rates of ED utilization across many surgical fields [10, 11]. These trends may be indicative of a larger issue regarding access to healthcare for these groups, such as inability to follow-up with a primary care provider and instead presenting directly to ED. A greater prevalence of emergent repairs in the publicly insured cohort may also be reflective of the difficulties patients face in obtaining specialized surgical care in an elective setting, perhaps having to wait until their hernia has incarcerated or strangulated. These patients may be unable to access elective repair or a multitude of reasons, ranging from availability of a provider to inability to pay. Regardless of the individual circumstance that necessitate delay in care, publicly insured and uninsured patients often present with larger hernias and overall worsened disease state (i.e., greater comorbidity burden, greater rate of emergent repair), as demonstrated in this study, and subsequently face increased risk of complication and poor outcomes. Our results confirm these findings and suggest that publicly insured patients may warrant special intervention/monitoring after discharge to prevent readmission and ED utilization. Previous studies seeking to address insurance-related gaps in care through specialized interventions have found evidence of improved outcomes and reduced readmissions and ED visits for patients participating in these programs [12,13,14,15], as well as beneficial cost savings to the health system in terms of reduced healthcare utilization [15]. While similar models may be beneficial among patients undergoing hernia repair, including coordination with community health sites, increased follow-up, and additional instruction regarding appropriate postdischarge care, data regarding the efficacy of these types of interventions in the hernia disease space are limited and should be an area of focus for future studies.

While this work is important in the field of hernia and surgery as a whole, there are several limitations that must be addressed. Data obtained from the national ACHQC registry may have discrepancies between participating sites. However, the ACHQC has previously adopted standards for data entry which seek to minimize this variation. The ACHQC consists of primarily high-volume hernia surgeons, so results may not be generalizable to everyone. The comparison groups in this study are also limited by a lack of specificity in regards to self-pay insurance, because it may also contain patients who elect to pre-pay for surgery instead of billing through insurance. As a result, the self-pay group may not be fully representative of the uninsured patient population. Importantly, insurance was used as a marker of low socioeconomic status and therefore older patients were excluded as all adults 65 or older become publicly insured and therefore lose the nuance of SES in analysis. However, there are likely important socioeconomic differences within this older cohort which should be explored in future studies which have more granular data available. Finally, some outcomes may be subject to response bias wherein the patients who returned to the ED for additional care have an increased opportunity to have complications indicated in their record, as opposed to patients who do not return for additional care and may therefore appear to exhibit lower rates of these outcomes. However, by utilizing multivariate analysis to control for these factors, this analysis is strengthened and the results are made more reliable.

This paper fills an important gap in the literature and provides a foundation for future studies which further explores the complex interplay of socioeconomic vulnerability, public health, and surgery. Patients with public insurance required increased ED care, had more complications, and were more frequently readmitted. Evidencing these inequities on the basis of insurance type serves as a small step toward supporting L-SES patients and understanding their unique care needs, while contextualizing their experience of hernia disease. Future studies should continue to explore this area and provide additional context for patients undergoing VHR.

Conclusion

This study demonstrated that public and self-pay insurance are associated with worse postoperative outcomes compared to private insurance, including increased odds of postoperative complication, ED visit, and readmission. In an effort to promote health equity, surgical providers need to assess how parameters beyond physical presentation may impact a patient’s health and take these into consideration when weighing operative intervention for VHR, while working to support vulnerable patients in the perioperative period as they have demonstrated increased risk for poor outcomes.