The Effect of Insurance Status on Surgical Outcomes in Gynecologic Cancer Patients

Abstract

Objective:

The aim of this research was to determine the impact of insurance status on 30-day surgical outcomes for the treatment of gynecologic cancer.

Materials and Methods:

A retrospective cohort study of surgically treated gynecologic oncology patients in a large, prospective, cancer-survivorship cohort from April 2010 to August 2016 was performed. Inclusion criteria were: (1) diagnosis of gynecologic cancer; (2) surgical management of the cancer; and (3) documented insurance status. Primary outcomes were any 30-day postoperative complications (Clavien–Dindo score ≥1) and serious 30-day complications (Clavien–Dindo score ≥2). Exposure of interest was insurance status at time of diagnosis, classified as private (PRI), public (PUB), or no insurance/self-pay (NI/SP). Relative risks (RRs) of postoperative complications were estimated using log binomial regression.

Results:

Overall, 458 patients met the inclusion criteria, of which 67% (n = 307) had PRI, 25% (n = 116) had PUB, and 8% (n = 35) had NI/SP. After adjusting for body mass index, cancer stage, and surgical approach, there was no difference in risk of any complications between NI/SP and PUB (RR: 0.68; 95% confidence interval [CI]: 0.43, 1.08) or PRI (RR: 0.89; 95% CI: 0.60, 1.34), or between PUB and PRI (RR: 1.31; 95% CI: 0.93, 1.84). There was also no difference in risk of serious complications between NI/SP and PUB (RR: 1.23; 95% CI: 0.49, 3.04) or PRI (RR: 1.33; 95% CI: 0.57, 3.11), or between PUB and PRI (RR: 1.09; 95% CI 0.66, 1.79).

Conclusions:

Insurance status did not influence the risk of 30-day postoperative complications in this North Carolina cohort of gynecologic cancer patients.

Introduction

Insurance status has been shown to influence many levels of cancer care, ranging from prevention to treatment and clinical outcomes.^1–3 Insurance status has also been shown to influence morbidity and mortality in patients with gynecologic malignancies.^4,5 Reduced access to care experienced by uninsured patients puts them at increased risk of advanced-stage disease at diagnosis and worse overall survival.^4–7

This study was conducted to investigate the influence of insurance status on postoperative surgical complications in gynecologic cancer patients treated at a large tertiary-care center in North Carolina. Recognizing the association between insurance status and surgical outcomes at a large state hospital where care is provided regardless of a patient's ability to pay could provide insight into the national implications of a single-payor model.

Materials and Methods

This study was approved (#17-0623) by the institutional review board (IRB) of the University of North Carolina (UNC) at Chapel Hill as a retrospective analysis of patients enrolled in a prospective public hospital–based cohort study of cancer survivors from April 2010 through August 2016 known as the UNC Health Registry/Cancer Survivorship Cohort (HR/CSC). Specifically, patients were recruited from outpatient clinics at the North Carolina Cancer Hospital (NCCH), which is the only North Carolina public hospital that treats patients regardless of ability to pay. Roughly half of all patients in solid-tumor oncology clinics were contacted, of which ∼50% were enrolled. Although the enrolled group was only a quarter of all patients seen in the clinics, demographics for the HR/CSC matched that of all UNC hospitals. Participants enrolled in the UNC HR/CSC underwent prospective collection of data ranging from self-reported demographics to multiple validated questionnaires at the time of study enrollment.

For the current study, HR/CSC patients were included according to the following criteria: diagnosis of gynecologic cancer; surgical treatment for the cancer; and documentation of insurance status at the time of diagnosis. Baseline demographics and patient characteristics were obtained from the prospectively obtained patient data within the registry. These included age at diagnosis, self-reported ethnicity/race, educational attainment, employment status, and marital status. A retrospective chart review was performed to obtain insurance status, date of diagnosis, body mass index (BMI), primary disease site, stage of disease at time of diagnosis, surgical approach, and 30-day surgical complications. Chart abstraction was performed by 2 independent members of the study team and was cross-checked for consistency. Surgical approach was categorized as open surgery, minimally invasive surgery (MIS), and vulvar/vaginal approach. Stage of disease at diagnosis was defined as early (stage I or II) or advanced (stage III or IV). Obesity was modeled as a continuous variable.

The primary outcome of interest was the presence of any 30-day surgical complications as well as the presence of serious 30-day surgical complications. Surgical complications were measured according to the validated Clavien–Dindo classification (Appendix 1).⁸ A Clavien–Dindo score 1 denotes of any deviation from the typical postoperative course that does not require invasive treatment. Therefore, patients with Clavien–Dindo scores ≥1 were classified as having any surgical complication within 30 days. The presence of serious 30-day surgical complications, defined as a Clavien–Dindo score ≥2, was also evaluated. This corresponds to a surgical complication requiring radiologic, surgical, or endoscopic interventions for treatment.

The primary exposure of interest was insurance status at the time of diagnosis. Insurance status was categorized as private (PRI), public (PUB), and no insurance/self-pay (NI/SP) as documented at the first visit after a confirmed diagnosis. Patients with both PRI and PUB insurance coverage were classified as PRI.

Statistical analysis

Log binomial regression was used to estimate relative risks (RRs) with 95% confidence intervals (CIs). Covariates of interest included previous diagnosis of hypertension or diabetes mellitus, obesity, disease stage at diagnosis, and surgical approach. Model variables were chosen using backward selection at the 0.20 α level. Final regression models controlled for surgical approach, disease stage, and BMI. SAS (version 9.4) was used for statistical analysis. All testing was two-sided. p-Values <0.05 were considered statistically significant for all analyses.

Results

Overall demographics of the sample are shown in Table 1. A total of 457 patients were included in the study with diagnosis dates ranging from April 2003 to October 2015. Of these, 306 (67%) had PRI, 116 (25%) had PUB, and 35 (8%) had NI/SP. A majority of the sample was white (83%), had uterine cancer (66%), was diagnosed as an early stage (76%), and underwent MIS (67%). Ultimately, 32% (n = 147) experienced any 30-day postoperative complications and 16% (n = 73) had serious 30-day surgical complications.

Table 1.

Population Characteristics

Characteristics	Total ^a	Private insurance	Public insurance	Self-pay/ no insurance	p-Value
Sample size	457	306 (67%)	116 (25%)	35 (7.7%)
Median age (yrs)	61	60	67	49	< 0.01
Median BMI (kg/m²)	32.2	31.3	35.3	34	< 0.01
Race
White	377 (83%)	266 (87%)	89 (77%)	22 (65%)	< 0.01
Nonwhite^b	78 (17%)	39 (13%)	27 (23%)	12 (35%)
Education
High school or less	142 (31%)	75 (25%)	51 (44%)	16 (46%)	< 0.01
Some college or more	315 (69%)	231 (75%)	65 (56%)	19 (54%)
Employment status
Yes	216 (47%)	187 (61%)	17 (15%)	12 (34%)	< 0.01
No/not specified	239 (53%)	119 (39%)	98 (85%)	23 (66%)
Marital status
Divorced	72 (16%)	45 (15%)	19 (16%)	^c
Married	259 (57%)	189 (62%)	60 (52%)	10 (29%)	< 0.01
Single, never married	49 (11%)	30 (9.8%)	^c	10 (29%)
Widowed	54 (12%)	29 (9.5%)	21 (18%)	^c
Other	22 (5%)	12 (4%)	^c	^c
Disease site
Ovarian	80 (18%)	58 (19%)	16 (14%)	^c
Uterine	303 (66%)	203 (66%)	83 (72%)	17 (49%)	0.04
Cervix	55 (12%)	34 (11%)	^c	10 (29%)
Vulva/vagina	19 (4.2%)	11 (3.6%)	^c	^c
Stage at diagnosis
I	314 (69%)	208 (68%)	79 (68%)	27 (77%)
II	31 (6.8%)	22 (7.2%)	^c	^c	0.89
III	93 (20%)	63 (21%)	25 (22%)	^c
IV	19 (4.2%)	13 (4.3%)	^c	^c
Surgical approach
Open	122 (27%)	84 (27%)	22 (19%)	16 (46%)	0.01
Minimally invasive	306 (67%)	208 (68%)	82 (71%)	^c
Vulvar/vaginal	29 (6.4%)	14 (4.6%)	12 (10%)	^c
Any 30-day complications
No	310 (68%)	206 (67%)	84 (72%)	20 (57%)	0.23
Yes	147 (32%)	100 (33%)	32 (28%)	15 (43%)
Serious 30-day complications
No	384 (84%)	257 (84%)	97 (84%)	^c	0.96
Yes	73 (16%)	49 (16%)	19 (16%)	^c

Note: Demographic & diagnostic information of patients who underwent surgical treatment for gynecologic cancer at a single, large tertiary-care center in North Carolina. Patient characteristics according to insurance type are compared. Patients with multiple insurances documented were classified according to the best available information, with private insurance considered preferable over public insurance.

All data presented as no. (%) unless otherwise noted.

A majority of nonwhite participants were African American (>75%).

Cell sizes <10 are not reported to reduce the potential for reidentification of research subjects.

yrs, years; BMI, body mass index.

Patients with PRI tended to be younger and thinner than those with PUB (Table 1). A higher proportion of PUB (23%, n = 27) and NI/SP (35%, n = 12) patients reported nonwhite ethnicities, compared to PRI patients (13%, n = 39; p < 0.01). PRI patients were more likely to have a higher education and be employed (p < 0.01). All insurance groups had similar distributions of disease sites and stages at diagnosis. A higher proportion of NI/SP patients underwent open surgery (46%, n = 16), compared to PRI and PUB patients (PRI: 27%; PUB: 19%; p < 0.01).

Overall, 33% (n = 100) of PRI, 28% (n = 32) of PUB, and 43% (n = 15) of NI/SP patients experienced any surgical complication within 30 days (p = 0.23). More specifically, 29% (n = 10) of NI/SP were documented as having Clavien–Dindo score 1 complications, compared to only 17% (n = 51) of PRI patients and 11% (n = 13) of PUB patients (p = 0.41). The frequency of serious 30-day surgical complications was similar among insurance groups with 16% of PRI (n = 49) and PUB (n = 19) patients experiencing serious postoperative complications (p = 0.96).

No statistically significant difference in risk of surgical complications was seen among insurance types in any of the crude or fully adjusted models (Table 2). After adjusting for cancer stage, BMI, and surgical approach, NI/SP had no increased risk of any surgical complications, compared to PRI patients (RR: 0.89; 95% CI: 0.60, 1.34) or PUB patients (RR: 0.68; 95% CI: 0.43, 1.08). There was also no statistically significant difference in risk of any surgical complications between PRI and PUB patients (RR: 1.31; 95% CI: 0.93, 1.84). When comparing rates of serious surgical complications, there was no increased risk between NI/SP patients and PRI patients (RR: 1.33; 95% CI: 0.57, 3.11) or PUB patients (RR: 1.23; 95% CI: 0.49, 3.04) after adjusting for cancer stage, BMI, and surgical approach. The risk of serious 30-day surgical complications was also similar between PRI and PUB patients (RR: 1.09; 95% CI: 0.66, 1.79).

Table 2.

Relative Risks of Surgical Complications

	Any complications (CD ≥1)		Serious complications (CD ≥2)
Insurance	Unadjusted RR (95% CI)	Adjusted^a RR (95% CI)	Unadjusted RR (95% CI)	Adjusted^a RR (95% CI)
Private vs. public	1.18 (0.85, 1.66)	1.31 (0.93, 1.84)	0.98 (0.60, 1.59)	1.09 (0.66, 1.79)
Private vs. uninsured	0.76 (0.50, 1.15)	0.89 (0.60, 1.34)	1.12 (0.48, 2.63)	1.33 (0.57, 3.11)
Public vs. uninsured	0.64 (0.40, 1.04)	0.68 (0.43, 1.08)	1.15 (0.46, 2.85)	1.23 (0.49, 3.04)

Note: Relative risks with 95% CIs of surgical complications according to insurance status were estimated using log binomial regression. Both the crude and fully adjusted models are presented for the RR of having any 30-day surgical complications & serious 30-day surgical complications.

Adjusted for stage, body mass index, and surgical approach.

RR, relative risk; CI, confidence interval.

Discussion

Insurance status did not influence surgical outcomes in this single-institution cohort of gynecologic cancer patients. There was no statistically significant difference in surgical complication rates among PRI, PUB, and NI/SP patients. A larger proportion of NI/SP patients underwent open surgery and experienced minor postoperative complications, compared to PRI and PUB patients. However, insurance status was not found to be associated with complication severity after adjusting for surgical approach.

Overall, similar rates of serious surgical complications were seen among PRI, PUB, and NI/SP patients, suggesting that quality of surgical care was not influenced by insurance status at this large public hospital. Several studies have compared the quality of surgical care received by gynecologic patients with different insurance types using metrics such as readmission rates, length of stay, and 30-day surgical complications.^3,9,10

Nakayama et al. performed a similar retrospective, single-institution study investigating the risk factors for readmission in postoperative gynecologic oncology patients at the University of Virginia (n = 334).³ Using insurance status as a surrogate for socioeconomic status, this study found PUB patients more likely to be readmitted within 30-days of discharge than PRI patients. However, a majority of Nakayama et al.'s cohort underwent open surgery, whereas most of the NCCH cohort underwent minimally invasive procedures, possibly explaining why the current study did not find this discrepancy in care.

Bradley et al. performed a retrospective analysis of all acute-care hospitals in Virginia from 1999 to 2005, comparing length of stay and costs between PRI and PUB breast-cancer patients undergoing mastectomies (n = 6201).⁹ After adjusting for stage and radiation therapy, there was no statistically significant difference between Medicaid-insured and PRI patients. These findings agree with those of the current study, although it is difficult to compare breast-cancer patients to the current study's population of gynecologic cancer patients.

The NCCH findings also contrasted with those of Swenson et al., who found Medicaid and Medicare patients had increased odds of major postoperative complications in a retrospective analysis of hysterectomy patients in Michigan (n = 16,548).¹⁰ These conflicting results could be accounted for by the difference in population sizes and compositions. Swenson et al. included both benign and malignant gynecologic patients, finding gynecologic cancer as an individual risk factor for surgical complications. The current study was limited to a much-smaller cohort of only gynecologic cancer patients in the NCCH. To the current authors' knowledge, no studies have focused solely on the gynecologic oncology population to investigate the influence of insurance status on rates of severe surgical complications.

The proportion of NI/SP patients reporting Clavien–Dindo score 1 complications was nearly twice that of PRI and PUB patients in this cohort. This could be explained by a higher proportion of NI/SP undergoing open surgery. These findings aligned with those of Nakayama et al. who found MIS to be associated with fewer overall readmissions.³ Despite the known benefits of MIS, this surgical approach is less likely to be used for NI/SP women in the treatment of gynecologic cancers.^11–13 This could be a result of decreased access to care leading to late presentation. Additionally, barriers to care may also complicate the recovery period for NI/SP patients. Previous studies have shown that, compared to PUB patients, NI/SP patients are less likely to utilize prescriptions, less likely to have a usual source of care, and more likely to report unmet medical needs.^14,15 As a result of insufficient access to primary care, many NI/SP patients are unable to perform basic wound care at home, making them vulnerable to preventable postoperative complications such as surgical-site infections.³ These findings suggest that NI/SP would benefit from patient navigators and other resources to help prevent avoidable complications.

Initially it was hypothesized that the increased rate of minor complications among the NI/SP patients in this cohort could be attributed to the large proportion of rural patients in North Carolina who lack access to primary care.¹⁶ Further analysis, however, revealed equal distribution of complication rates based on rural residency (data not shown). Data regarding other possible explanations for this discrepancy, such as access to transportation and geographic distance to treatment facilities, were not available for this cohort but should be considered in future studies.¹⁶

There were several limitations to the current study. This study was a preliminary exploratory study that warrants a multicenter institutional investigation with a larger, more-diverse population. While the overall cohort size was large, the small number of NI/SP patients limited the ability of this study to contrast this group to PRI or PUB patients. Although most of the data were collected prospectively, estimation of surgical complications required chart abstraction with inherent flaws of loss to follow-up, care received at alternate institutions, and/or lack of documentation in the medical records.

Evaluation of a larger cohort with more NI/SP patients could illustrate the relationship between insurance status and postoperative complications better. While the data showing no difference in outcomes by insurance status is reassuring and lends support to the potential benefits of a single-payor system, future research could compare a cohort of patients cared for in the private sector to those at a public hospital to evaluate the impact of insurance status further. Finally, it would be beneficial to study a cohort with a more-even distribution of surgical approaches in order to isolate the influence of insurance status on surgical complications. Future research should focus on helping NI/SP and underinsured patients receive timely access to equitable care to avoid preventable postoperative adverse events.

Conclusions

Insurance status did not affect the risk or influence the severity of 30-day surgical complications in this cohort of gynecologic cancer patients treated at a major, tertiary public hospital. Disproportionate minor complications in NI/SP patients suggest a targetable area for improvement. While exploratory in nature, this study raises questions that should be investigated on a larger scale to evaluate the equity of care received by gynecologic oncology patients.

Footnotes

Acknowledgments

This study was approved by the UNC's IRB (#17-0623).

The authors thank the UNC HR/CSC participants for their important contributions. The HR/CSC is funded in part by the UNC Lineberger Comprehensive Cancer Center's University Cancer Research Fund. This project was reviewed and approved by the Human Research Protections Program (IRB number: 09-0605) at the UNC.

Author Disclosure Statement

No financial conflicts of interest exist.

Appendix I:

Clavien–Dindo Classifications of Postoperative Complications⁸

Grade	Definition
Grade I	Any deviation from the normal postoperative course without the need for pharmacologic treatment or surgical, endoscopic, and radiologic interventions Allowed therapeutic regimens are: drugs as antiemetics; antipyretics; analgesics; diuretics; electrolytes; and physiotherapy. This grade also includes wound infections opened at the bedside
Grade II	Requiring pharmacologic treatment with drugs other than such allowed for grade I complications Blood transfusions and total parenteral nutrition are also included
Grade III	Requiring surgical, endoscopic, or radiologic intervention
Grade IIIa	Intervention not under general anesthesia
Grade IIIb	Intervention under general anesthesia
Grade IV	Life-threatening complication (including CNS complications)^a requiring IC/ICU management
Grade IVa	Single-organ dysfunction (including dialysis)
Grade IVb	Multiorgan dysfunction
Grade V	Death of patient

Brain hemorrhage, ischemic stroke, or subarachnoidal bleeding, but excluding transient ischemic attacks.

CNS, central nervous system; IC, intermediate care; ICU, intensive care unit.

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