Comparison of Pediatric Laparoscopic Appendectomy Outcomes Between Teaching and Nonteaching Hospitals: A Multi-Institutional Study

Introduction

There has been continued debate over the quality of care delivered at teaching hospitals. Further, there continues to be the dual challenge of training future surgeons while providing the highest quality of care to patients. There have been few studies that have evaluated surgical outcomes at teaching hospitals in comparison with nonteaching hospitals. For the most part, these articles demonstrate comparable morbidity and mortality, although the length of stay appears to be longer at the teaching facilities.^1–5 The limitations of the prior mentioned studies are that they are evaluating outcomes of complex procedures where residents typically play the role of an assistant rather than as the primary surgeon.

Recently, we performed a pilot study comparing outcomes of appendicitis at one teaching versus one nonteaching institution. ⁶ However, the main criticism of this study was that it only involved a single teaching and nonteaching institution and the use of laparoscopy was dramatically different. Thus, the aim of this study was to perform a multi-institutional study comparing outcomes of laparoscopic appendectomy (LA) between teaching and nonteaching hospitals.

Methods

After Institutional Review Board approval, a retrospective review of all patients <18 years of age undergoing LA for appendicitis between 1998 and 2007 at 12 hospitals was performed. Two were teaching hospitals (Harbor-UCLA Medical Center and Kaiser Permanente, Los Angeles Medical Center) and 10 were nonteaching Kaiser Permanente hospitals. At both teaching institutions, the surgical residents are actively involved in all aspects of patient care. They are the first to see consultations in the emergency room, serve as the primary surgeon, direct the postoperative care, and see patients back in clinic after discharge. Senior resident surgeons at the teaching institutions typically serve as teaching assistants for LA cases under attending supervision. In contrast, there are no residents at the nonteaching institutions, and the attending surgeon performs all aspects of patient care.

At the 11 Kaiser Permanente facilities, data were collected from the Kaiser Permanente discharge abstract database. This database includes all inpatient and outpatient visits. All data are collected and entered in similar fashion at all Kaiser Permanente facilities. At Harbor-UCLA, patients were identified through the Harbor-UCLA database and charts were individually reviewed. Patient factors collected included age, gender, and the presence of perforation. Outcome variables were 30-day morbidity and length of hospitalization (LOH). Thirty-day morbidity included wound infection, postoperative abscess drainage, and readmission. LOH was determined by the date of admission and discharge. Thus, there would be no difference in LOH for patients admitted to the hospital versus admitted to observation status as long as there was an overnight stay. Outcomes of patients undergoing LA were compared between teaching and nonteaching hospitals. Patients with laparoscopic interval appendectomy or LA as part of another procedure were excluded.

All patient data were collected in an Excel database (Microsoft Excel, Microsoft Corporation, Redmond, WA) and translated into native SAS format using DBMS/Copy^® (Dataflux Corporation, Cary, NC). Descriptive statistics were calculated for all variables. Numerical variables were compared using the nonparametric Wilcoxon rank sum test and are reported as medians with interquartile ranges. Categorical or nominal variables were compared using the chi-square test or Fisher's exact test, as appropriate.

Results

Overall, 542 patients with appendicitis were treated at the teaching institutions and 3012 at the nonteaching institutions. The mean age was 11 years at the teaching institutions and 13 years at the nonteaching institutions. Sixty-two percent of patients were male at the teaching institutions and 60% at the nonteaching institutions. The perforated appendicitis rate was 33% at the teaching institutions and 22% at the nonteaching institutions (P < 0.0001).

Outcomes data are summarized in the Table 1. For nonperforated appendicitis, there was no difference in the rates of wound infection, postoperative abscess drainage, or readmission between teaching and nonteaching institutions. LOH was longer at the teaching institutions (teaching = 2.1 ± 1.7 versus nonteaching = 1.6 ± 1.6 days, P = 0.02).

For perforated appendicitis, there were lower rates of wound infection (teaching = 1.7% versus nonteaching = 7.0%, P = 0.004), abscess drainage (teaching = 4.0% versus 9.6%, P = 0.01), and readmission (teaching = 0.6% versus nonteaching = 8.9%, P < 0.0001) at the teaching facilities. The LOH was longer at the teaching institutions (teaching = 5.7 ± 3.2 versus nonteaching = 4.8 ± 3.2 days, P = 0.002).

Discussion

Given the recent focus on patient safety and outcomes, it is important to document the quality of care at teaching institutions. Previous studies examining complex procedures, such as pancreatic resections and cardiac bypass procedures, have shown similar outcomes at teaching and nonteaching institutions.^1,4–5 The limitations of the prior mentioned studies are that they evaluated outcomes of complex procedures where residents typically play the role of an assistant rather than as the primary surgeon. Looking at more routine operations, Hwang et al. evaluated the outcomes of five common operations (bowel resection, laparoscopic cholecystectomy, hernia repair, mastectomy, and appendectomy) performed with and without residents. Comparing all procedures together, there were no differences in complications between the groups, although there was greater mortality, a greater duration of stay, and higher costs in the resident group. ⁷

A prior study by our institution, which compared one teaching and one nonteaching hospital, found comparable quality of care when outcomes for pediatric appendicitis were analyzed. However, when looking closely at the data, there was a trend toward a higher wound infection rate at the teaching institution for both nonperforated appendicitis (3.1% versus 1.7%, P = 0.07) and perforated appendicitis (14.3% versus 9.1%, P = 0.05). Further, there was also a trend toward a lower rate of postoperative abscess drainage for nonperforated appendicitis in the teaching institution (0.2% versus 1.1%, P = 0.08). Finally, LA was utilized far less frequently at the teaching institution (12% versus 59%, P < 0.0001), which may further impact the morbidity at the two institutions. Thus, we chose to perform a larger, multi-institutional study to look specifically at the outcomes of LA. Unlike our previous study, this multi-institutional study demonstrated similar morbidity with respect to wound infection, abscess drainage, and readmission rates for patients with nonperforated appendicitis. An unexpected finding was that morbidity was lower in patients with perforated appendicitis at teaching hospitals. With respect to wound infection, we would have expected the opposite results given the relative inexperience of surgical residents on gentle tissue handling. It may be that tissue handling is not as crucial for LA given the small wounds. The teaching difference in abscess formation may be due to the severity of the clinical illness associated with perforated appendicitis. However, this was not specifically studied and would be difficult to assess. Infectious complications may also reflect the type and duration of antibiotics administered; again, this was not specifically looked at. One may also speculate that the longer LOH at the teaching institutions may have resulted in a longer course of intravenous antibiotics, thus resulting in a lower abscess rate. Further, one can also speculate that the longer LOH at the teaching institutions may have also led to the lower readmission rates seen at these institutions. Finally, the reason for the lower morbidity at the teaching institutions may be as simple as a volume effect. The volume of patients with perforated appendicitis seen at the institutions undergoing LA was nearly 50% higher at each teaching institution than at each nonteaching institution as reflected by the case numbers and perforation rates documented above. This increased volume may have led to improved results similar to other procedures performed at high volume centers.

Despite similar morbidity for nonperforated appendicitis and lower morbidity for perforated appendicitis, we found longer LOH following LA at the academic centers. This longer LOH may reflect the cautious nature of surgical residents; they would rather error on the side of keeping patients in the hospital longer rather than discharge too early. Previous studies have linked increased costs at teaching institutions due to increased LOH. Although we did not perform a formal cost analysis, we feel that the cost differences for LA would be minimal between the institutions. The infectious complications and readmission rates were lower for perforated appendicitis at the teaching hospitals, which would help offset the cost for the longer LOH. In addition, the LOH for the readmission was not included in our analysis for this study, which would further increase the cost at the nonteaching institutions.

There are several limitations in this study. This study was a retrospective review and by nature has its limitations. Further, we did not specifically evaluate which resident year levels were performing the operation, nor did we document the degree of attending surgeon involvement. It may be that the majority of the cases performed were done by the more senior residents or with a high level of attending involvement, thus circumventing the true effect of the surgical trainees. Finally, this study was performed at multiple institutions with no set protocol on the clinical management of appendicitis. Thus, it is difficult to determine whether the differences seen in this study were due to practice style or due to the presence of surgical trainees. The only way to accurately determine the true effect of surgical residents is to perform a prospective study with identical management protocols at each institution. Despite these limitations, we feel that this study adds to the mounting evidence that surgical residents do not impact the quality of care provided at teaching institutions.

Conclusions

We demonstrated comparable outcomes for LA in pediatric patients with nonperforated appendicitis. With respect to LA in children with perforated appendicitis, we found better outcomes at teaching institutions. Our study refutes the bias among patients and the public regarding the care received at teaching hospitals.