Abstract
BACKGROUND
Many studies have identified racial disparities in healthcare, but few have described disparities in the use of anesthesia modalities. We examined racial disparities in the use of local versus general anesthesia for inguinal hernia repair. We hypothesized that African American and Hispanic patients would be less likely than Caucasians to receive local anesthesia for inguinal hernia repair.
MATERIALS AND METHODS
We included 78,766 patients aged ≥18 years in the Veterans Affairs Surgical Quality Improvement Program database who underwent elective, unilateral, open inguinal hernia repair under general or local anesthesia from 1998–2018. We used multiple logistic regression to compare use of local versus general anesthesia and 30-day postoperative complications by race/ethnicity.
RESULTS
In total, 17,892 (23%) patients received local anesthesia. Caucasian patients more frequently received local anesthesia (15,009; 24%), compared to African Americans (2353; 17%) and Hispanics (530; 19%), p < 0.05. After adjusting for covariates, we found that African Americans (OR 0.82, 95% CI 0.77–0.86) and Hispanics (OR 0.77, 95% CI 0.69–0.87) were significantly less likely to have hernia surgery under local anesthesia compared to Caucasians. Additionally, local anesthesia was associated with fewer postoperative complications for African American patients (OR 0.46, 95% CI 0.27–0.77).
CONCLUSIONS
Although local anesthesia was associated with enhanced recovery for African American patients, they were less likely to have inguinal hernias repaired under local than Caucasians. Addressing this disparity requires a better understanding of how surgeons, anesthesiologists, and patient-related factors may affect the choice of anesthesia modality for hernia repair.
Keywords: Veterans, Racial disparity, Ethnic disparity, Local anesthesia, Inguinal hernia repair
INTRODUCTION
Despite ongoing efforts to address inequality in the US healthcare system, there are still considerable racial disparities in access to care modalities that can affect clinical outcomes.1 Most studies of racial and ethnic disparities in surgery have focused on access to new surgical techniques or devices (such as robotic and laparoscopic surgery), or on biases that affect diagnosis and quality of care. Few studies in the surgical literature have focused on disparities in access to anesthesia modalities and how this can affect postoperative outcomes.2–6
Inguinal hernia repair is the most common general surgery procedure in the US, and the operation can be performed under general or local anesthesia.7 Several studies have shown that using local rather than general anesthesia for hernia surgery leads to fewer postoperative complications and reduced operative time.8–10 Despite the potential advantages of local anesthesia for hernia surgery, the majority of operations in the United States continue to be performed under general anesthesia.8,9,11 Although the overall utilization of local anesthesia for inguinal hernia surgery is low, it is unclear whether use of local varies according to patients’ race or ethnicity. Given the advantages of local anesthesia for inguinal hernia repair, it is important to identify and subsequently address any racial or ethnic disparities in the use of local anesthesia. Since this operation is so common, even small improvements in outcomes can have profound effects on healthcare in the United States because so many patients stand to benefit.
The purpose of this project was to evaluate whether use of local anesthesia for open inguinal hernia repair differed according to patients’ race and ethnicity. We hypothesized that African American and Hispanic patients would be less likely than Caucasian patients to have their inguinal hernias repaired under local anesthesia. Further, we hypothesized that the use of local rather than general anesthesia would be associated with fewer postoperative complications regardless of race/ethnicity.
MATERIALS AND METHODS
Patient selection and setting
This project was approved by the VA North Texas Health Care System Institutional Review Board. The Institutional Review Board also approved waiver of informed consent. We screened the Veterans Affairs Surgical Quality Improvement Program (VASQIP) Database from 1998–2018. We included all adults aged 18 years and older who had an initial, elective, open, unilateral inguinal hernia repair. Patients were selected based on Common Procedural Terminology code 49505.
We excluded patients who had concurrent procedures, other procedures not consistent with inguinal hernia repair, bilateral hernias, preoperative ventilator dependence, primary surgical specialty coded as something other than general surgery, anesthesia coded as epidural, spinal, regional, or unknown, and those whose race/ethnicity was not coded as Caucasian, African American, or Hispanic.
Outcomes
The primary outcome was use of local rather than general anesthesia for hernia repair. Secondary outcomes included incidence of any VASQIP captured postoperative complication, operative time (from patient entrance to exit from operating room), and post anesthesia care unit (PACU) time. Complications were defined according to the VASQIP data dictionary and included wound infection, dehiscence, pneumonia, reintubation, pulmonary embolus, failure to wean from the ventilator, renal insufficiency/failure, urinary tract, stroke, cardiac arrest, myocardial infarction, postoperative bleeding that requires transfusion, deep vein thrombosis, sepsis/septic shock, and reoperation.
Independent variable
The independent variable was the patient’s race/ethnicity as identified within the VASQIP database: Caucasian, African American, or Hispanic.
Statistical analysis
We used chi square analysis for univariable analysis of categorical variables and analysis of variance for continuous variables across the 3 race/ethnic groups. Multivariable logistic regression was used to estimate the effect of race/ethnicity on complication risk, adjusting for percent of cases done under local anesthesia at each particular hospital. We used multiple linear regression for estimating operative and recovery time. Cluster robust standard error was used for all multivariable analysis, which accounted for clustering within hospital systems.12 To enhance model performance, time was log transformed to increase normality. Consequently, all changes in time are expressed as semi-elasticities (percent change in dependent variable with unit change in the independent variable). We assessed functional forms for continuous variables and ran standard model diagnostics, including residual plots, to assess fit and adequacy of model assumptions. We also used a time-series analysis to evaluate changes in use of local anesthesia in racial/ethnic groups over time. Statistical analysis was performed using Stata 16.1 (StataCorp. 2019. Stata Statistical Software: Release 16.1. College Station, TX: StataCorp LLC). Results were considered significant at p<0.05.
RESULTS
Patient characteristics
In total, 78,766 patients were included in our analysis. Of those, 61,844 (78.5%) were Caucasian, 14,144 (18.0%) were African American, and 2,778 (3.5%) were Hispanic (Table 1). Caucasian patients tended to be older, with a median age of 64 years (IQR 48–80) compared to 60 years (IQR 45–75) for African Americans and 62 years (IQR 44–80) for Hispanic patients (p<0.0001). However, Caucasian patients were less likely than African American or Hispanic patients to have an American Society of Anesthesiology score of at least 3 (p<0.0001).
Table 1.
Patient and perioperative characteristics.
| Variable | Caucasian | African American | Hispanic | P value |
|---|---|---|---|---|
| n=61,844 | n=14,144 | n=2,778 | ||
| Age, median years (IQR) | 64 (16) | 60 (15) | 62 (18) | <0.0001 |
| Body Mass Index, median kg/m2 (IQR) | 25.6 (5.0) | 25.3 (5.4) | 26.1 (5.3) | <0.0001 |
| Male gender | 61,539 (99.5%) | 14,070 (99.5%) | 2,765 (99.5%) | 0.9 |
| Local anesthesia | 15,009 (24.3%) | 2,353 (16.6%) | 530 (19.1%) | <0.0001 |
| American Society of Anesthesiology class | <0.0001 | |||
| 1 | 2,813 (4.6%) | 554 (3.9%) | 173 (6.2%) | |
| 2 | 26,656 (43.1%) | 5,728 (40.5%) | 1,276 (45.9%) | |
| 3+ | 32,370 (52.3%) | 7,862 (55.6%) | 1,329 (47.8%) | |
| Attending involvement | <0.0001 | |||
| Attending alone | 20,972 (33.9%) | 3,471 (24.5%) | 789 (28.4%) | |
| Attending in OR | 36,252 (58.6%) | 9,615 (68.0%) | 1,823 (65.6%) | |
| Attending available | 747 (1.2%) | 275 (1.9%) | 58 (2.1%) | |
| Unknown | 3,873 (6.3%) | 783 (5.5%) | 108 (3.9%) | |
| Post graduate year of surgeon of record | <0.0001 | |||
| Attending alone | 29,566 (47.8%) | 5,133 (36.3%) | 1,289 (46.4%) | |
| Intern | 8,170 (13.2%) | 1,935 (13.7%) | 480 (17.3%) | |
| Second year | 7,068 (11.4%) | 1,868 (13.2%) | 287 (10.3%) | |
| Third year | 6,164 (10.0%) | 1,602 (11.3%) | 241 (8.7%) | |
| Fourth year | 3,065 (5.0%) | 995 (7.0%) | 103 (3.7%) | |
| Chief resident | 7,112 (11.5%) | 2,320 (16.4%) | 339 (12.2%) | |
| Post graduate year>5 | 699 (1.1%) | 291 (2.1%) | 39 (1.4%) | |
| Outpatient surgery | 59,125 (95.6%) | 13,239 (93.6%) | 2,644 (95.2%) | <0.0001 |
| Clean wound classification | 60,001 (97.0%) | 13,630 (96.4%) | 2,692 (96.9%) | 0.001 |
| Diabetes | <0.0001 | |||
| No diabetes | 55,947 (90.5%) | 12,298 (87.0%) | 2,385 (85.9%) | |
| Oral medications | 4,144 (6.7%) | 1,268 (9.0%) | 289 (10.4%) | |
| Insulin | 1,370 (2.2%) | 548 (3.9%) | 102 (3.7%) | |
| Dyspnea | <0.0001 | |||
| No dyspnea | 56,443 (91.3%) | 13,159 (93.0%) | 2,673 (96.2%) | |
| With minimal exertion | 4,877 (7.9%) | 914 (6.5%) | 98 (3.5%) | |
| At rest | 249 (0.4%) | 46 (0.3%) | 2 (0.07%) | |
| Functional status | <0.0001 | |||
| Independent | 60,615 (98.0%) | 13,799 (97.6%) | 2,729 (98.2%) | |
| Partially/totally dependent | 1,198 (1.9%) | 318 (2.3%) | 49 (1.8%) | |
| Smoking history | 19,845 (32.1%) | 5,928 (41.9%) | 758 (27.3%) | <0.0001 |
| Congestive heart failure | 1,693 (2.7%) | 379 (2.7%) | 67 (2.4%) | 0.08 |
| Hypertension | 24,554 (39.7%) | 6,976 (49.3%) | 1,114 (40.1%) | <0.0001 |
| History of stroke | 1,270 (2.1%) | 381 (2.7%) | 56 (2.0%) | <0.0001 |
| Disseminated cancer | 203 (0.3%) | 52 (0.4%) | 7 (0.3%) | 0.9 |
| Steroid use within 30 days | 721 (1.2%) | 159 (1.1%) | 30 (1.1%) | 0.9 |
| 10% weight loss | 539 (0.9%) | 135 (1.0%) | 25 (0.9%) | 0.9 |
| Chronic Obstructive Pulmonary Disease | 6,617 (10.7%) | 1,108 (7.8%) | 144 (5.2%) | <0.0001 |
| Dialysis | 199 (0.3%) | 194 (1.4%) | 17 (0.6%) | <0.0001 |
All values represent number (%) unless otherwise specified
African American and Hispanic patients were less likely to have their hernias repaired under local anesthesia
In our cohort, 17,892 patients (23%) had their hernias repaired under local anesthesia. On univariable analysis, Caucasian patients more frequently received local anesthesia (15,009, 24.3%) compared to African American (2,353, 16.6%) or Hispanic (530, 19.1%) patients (p<0.05).
After adjusting for the confounding variables shown in Table 1, we found that African Americans (OR 0.82, 95% CI 0.77–0.86) and Hispanics (OR 0.77, 95% CI 0.69–0.87) were significantly less likely than Caucasians to have inguinal hernia repair performed under local anesthesia. The predicted probabilities of having hernias repaired under local anesthesia, after adjusting for patient factors shown in Table 1, can be seen in Figure 1.
Figure 1.
Patients who were African American or Hispanic were less likely than Caucasian patients to receive local anesthesia for inguinal hernia repair.
We also analyzed the time trend for utilization of local anesthesia over the study period (Figure 2). Although the overall utilization of local anesthesia declined steadily for all groups, Caucasian patients remained more likely to have surgery under local anesthesia than African American or Hispanic patients throughout the study period.
Figure 2.
The use of local anesthesia for inguinal hernia repair has remained limited in African American and Hispanic patients over the study period.
For African American patients, local anesthesia was associated with reduced risk of postoperative complications
The unadjusted risk of having any postoperative complication was similar for the three racial/ethnic groups: Caucasian 798 (1.3%), African American 189 (1.3%), Hispanic 39 (1.4%), p=0.8). When we compared specific complications within racial/ethnic groups, African American patients who received local anesthesia had a reduced rate of postoperative urinary tract infection compared to those who received general anesthesia (0.08% vs 0.5%, p=0.006). There were no other statistically significant differences in individual complications, likely due to the overall low rate of each specific complication.
After adjusting for confounding variables (Figure 3), the use of local rather than general anesthesia was associated with lower risk of any postoperative complication for African American patients (OR 0.42, 95% CI 0.22–0.82, p=0.01). Although local anesthesia was also associated with fewer postoperative complications for Caucasian (OR 0.83, 95% CI 0.66–1.04) and Hispanic (0.40, 95% CI 0.10–1.56) patients, the differences were not statistically significant.
Figure 3.
Using local anesthesia for inguinal repair in African American patients was associated with a reduced postoperative complication rate.
Local anesthesia was associated with reduced operative and recovery time, especially in minority patients
African American patients had the longest median operative time (75 minutes, IQR 41.5) compared with Caucasians (68 minutes, IQR 39) and Hispanics (70 minutes, IQR 39) (p<0.0001). When local instead of general anesthesia was utilized, the operative time was reduced in all patients (62 vs 71 minutes, p<0.0001). The reduction in operative time was most evident in African American patients (65 vs 76 minutes, p<0.0001) but was also present in Caucasian patients (62 vs 70 minutes, p<0.0001) and Hispanic patients (65 vs 72 minutes, p<0.0001). A similar finding was noted on multivariable analysis; Caucasians had a reduced operative time of 7.9% (95% CI 7.0–8.8) when local anesthesia was used, whereas operative time was reduced by 14.9% (95% CI 12.8–17.0) in African American patients and 16.7% (95% CI 12.1–21.3) in Hispanics.
Hispanic patients spent the most time recovering in the PACU (median time 80 minutes, IQR 55), compared with Caucasians (71, IQR 45) and African Americans (75 minutes, IQR 46, p<0.0001). When local anesthesia was utilized, there was a lower amount of time spent in PACU for all groups. Hispanic patients experienced the largest difference in PACU time when local anesthesia was used (64 vs 85 minutes, p<0.0001) compared to African American (60 vs 77 minutes, p<0.0001) and Caucasian patients (60 vs 75 minutes, p<0.0001. On multivariable analysis, Caucasians had a reduction in PACU time of 26.3% (95% CI 24.8–27.8), African Americans had a reduction in PACU time of 26.9% (95% CI 23.5–30.2), and Hispanics had a reduction in PACU time of 27.4% (95% CI 19.8–34.9) when surgery was performed under local rather than general anesthesia.
DISCUSSION
Our study found that African American and Hispanic patients were less likely to have inguinal hernias repaired under local anesthesia than comparable Caucasian patients in this large sample of Veterans. This disparity in use of local anesthesia has potentially significant implications for patient care, since use of local was associated with shorter operative and recovery times and fewer postoperative complications. In particular, African American patients had significantly fewer postoperative complications when their operations were performed under local anesthesia. The overall magnitude of the effect is modest because the surgery is relatively low risk. However, given the high frequency of hernia surgery in the US, even small differences can have substantial effects.
There are several potential patient and provider-level explanations for our finding that non-Caucasian patients were less likely to have surgery under local anesthesia. Prior studies have noted that providers often perceive minority patients as less likely to adhere to medical instruction.13 Surgeons or anesthesiologists may anticipate that minority patients would be less likely to remain still during surgery and could preemptively opt for general anesthesia. Implicit biases also likely play a role in this disparity.14 There may also be cultural and/or language barriers that make providers or patients uncomfortable discussing use of local anesthesia for surgery. For instance, online resources regarding anesthesia modalities for Cesarean section have been shown to be inaccessible to non-English speaking patients, although this has not been directly studied for inguinal hernia repair.15 Additionally, there may be important differences in patient populations that affect their willingness to have surgery under local anesthesia. Ochroch, et al. (2007) noted that African American patients were more likely to refuse the use of epidural anesthesia, when recommended by an anesthesiologist.16 While we cannot determine which (if any) of these factors were influential in the current analysis, our findings raise the need to explore how various influences and considerations can affect patient care for hernia surgery.
Our study is novel because it is the first to investigate racial and ethnic disparities in anesthesia modalities for hernia surgery. Prior studies have identified that minorities are less likely than Caucasian patients to receive anesthesia modalities other than general anesthesia during Cesarean sections.4,5 Similarly, Memtsoudis et al. (2006) analyzed the National Survey of Ambulatory Surgery and found that minority patients (African American and “others”) were more likely to receive general anesthesia than Caucasian patients for inguinal hernia repair; however, this study lacked data on patient comorbidity and could not effectively risk-adjust.17 Our study is also novel because the large and nationally representative dataset was able to account for key patient factors that could influence choice of anesthesia. Lastly, the use of anesthesia modality for inguinal hernia repair for minority patients has not been previously analyzed within the Veterans Affairs healthcare system, where insurance/cost of care is not a significant barrier to receiving surgical treatment. This suggests that other factors are influencing whether patients are offered alternatives to general anesthesia for surgery.
Although our results suggest the presence of a significant disparity in the use of local anesthesia for inguinal hernia repair, there are several limitations of our approach. First, there are likely confounding variables which are not captured by VASQIP, including patient preference for local or general anesthesia. It is entirely possible that Caucasian, African American, and Hispanic patients are offered local anesthesia at similar rates, but that Caucasian patients are simply more willing to accept this option. A qualitative exploration of patient preferences across racial/ethnic groups could help identify this key difference. Next, VASQIP does not provide hernia specific details such as the size or reducibility of the hernia, although we were able to exclude inguinal hernias which were coded as incarcerated or strangulated based on the CPT code of record. It is possible that the choice of anesthesia was a reflection of the anticipated complexity of the operation and this may vary across racial/ethnic groups. Finally, our cohort consisted entirely of Veterans, and it is possible that non-Veteran populations may have different levels of access to local anesthesia. However, the VA is truly an equal access system where patients are not required to have private or other non-VA insurance to receive care. Consequently, we were able to directly study racial/ethnic differences in care without having to consider economic factors that could bias results. Additionally, the vast majority of inguinal hernia patients are men, so the VA population is actually fairly representative of this group.
CONCLUSIONS
We found that African American and Hispanic patients were less likely to have their inguinal hernia repairs under local anesthesia compared to Caucasian patients. This disparity was present even though we also found that local anesthesia was associated with enhanced postoperative recovery in African American patients. Our study highlights the need to further explore patient, surgeon, anesthesiology, and systems factors through qualitative interviews that can identify potential explanations for the disparities found in our study.
Highlights.
Minority patients were unlikely to receive local anesthesia for hernia repair.
African American patients had improved outcomes when local anesthesia was used.
There is a need to explore the factors giving rise to these healthcare disparities.
ACKNOWLEDGEMENTS
This work was supported by a GEMSSTAR grant from the National Institute of Aging (1R03AG056330; for C.J.B.). Dr. Brown was supported, in part, by a VA Rehabilitation R&D Merit Award (1 I01 RX001995). MB acknowledges funding support from National Institutes of Health Beeson K76AG057022 and additional support from National Institutes of Health P30AG028716 and the Duke Anesthesiology Department.
Footnotes
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The authors report no proprietary or commercial interest in any product mentioned or concept discussed in this article. Dr. Balentine is a member of the Editorial Board of the Journal of Surgical Research; as such, he was excluded from the entire peer-review and editorial process for this manuscript.
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