Impact of Early Cholecystectomy on the Cost of Treating Mild Gallstone Pancreatitis: Gallstone PANC Trial

Abstract

Background: The Gallstone Pancreatitis: Admission vs Normal Cholecystectomy (Gallstone PANC) Trial demonstrated that cholecystectomy within 24 hours of admission (early) compared with after clinical resolution (control) for mild gallstone pancreatitis, significantly reduced 30-day length-of-stay (LOS) without increasing major postoperative complications. We assessed whether early cholecystectomy decreased 90-day healthcare use and costs.

Study design: A secondary economic evaluation of the Gallstone PANC Trial was performed from the healthcare system perspective. Costs for index admissions and all gallstone pancreatitis-related care 90 days post-discharge were obtained from the hospital accounting system and inflated to 2020 USD. Negative binomial regression models and generalized linear models with log-link and gamma distribution, adjusting for randomization strata, were used. Bayesian analysis with neutral prior was used to estimate the probability of cost reduction with early cholecystectomy.

Results: Of 98 randomized patients, 97 were included in the analyses. Baseline characteristics were similar in early (n = 49) and control (n = 48) groups. Early cholecystectomy resulted in a mean absolute difference in LOS of -0.96 days (95% CI, -1.91 to 0.00, p = 0.05). Ninety-day mean total costs were $14,974 (early) vs $16,190 (control) (cost ratio [CR], 0.92; 95% CI, 0.73-1.15, p = 0.47), with a mean absolute difference of $1,216 less (95% CI, -$4,782 to $2,349, p = 0.50) per patient in the early group. On Bayesian analysis, there was an 81% posterior probability that early cholecystectomy reduced 90-day total costs.

Conclusion: In this single-center trial, early cholecystectomy for mild gallstone pancreatitis reduced 90-day LOS and had an 81% probability of reducing 90-day healthcare system costs.

Figure 1:

Patient selection flow chart. A total of100 patients were enrolled in the study; 98 patients were randomized after 2 patients met exclusion criteria for having severe gallstone pancreatitis. A third patient was excluded after randomization secondary to developmental delay that was not realized at the time of study enrollment. A total of 97 patients were included in the final economic evaluation, 49 patients in the early cholecystectomy arm and 48 patients in the control cholecystectomy arm.

Figure 2:

Probability of reducing 90-day total costs with early cholecystectomy. On Bayesian generalized linear regression model with γ distribution and log link, early cholecystectomy had an 81% probability of reducing 90-day total cost (Bayesian risk ratio 0.92, 95% CI 0.77 – 1.10). Area under the bell curve to the left of the vertical line represents the posterior probability (0.81) that early cholecystectomy reduces 90-day total cost.

Figure 3:

Distribution of total 90-day cost by treatment arm. Median treatment cost in the (A) early cholecystectomy group was 12177 (interquartile range [IQR] 9893 – 14974) vs 12291 (IQR 10401 – 19589) in the (B) control cholecystectomy group.