Hospital Cost Implications of Increased Use of Minimally Invasive Surgery

Minimally invasive surgery (MIS) is associated with decreased postoperative complication rates for common procedures,^1-3 yet the use of MIS in hospitals, by procedure, varies widely.⁴ Although the difference in complication rates associated with the divergent use of MIS among hospitals has been described,⁵ little is known about the potential cost savings associated with reducing complication rates. We designed a study to calculate the projected cost savings that could be possible with the increased use of MIS in hospitals.

This was an institutional review board–exempt study because patient data were de-identified and were approved as such by the Johns Hopkins University institutional review board. We used the 2010 National Inpatient Sample for patients undergoing an appendectomy, a partial colectomy, or a lung lobectomy.⁴ Patients presenting for emergency surgery or multiple operations, or those with a high-risk status, such as sepsis, were excluded. Seven postoperative complications listed among the Agency for Healthcare Research and Quality’s Patient Safety Indicators for surgical care were examined. Billed charges were multiplied by hospital cost to charge ratios. Multivariable, mixed linear regression models were used, accounting for patient and hospital factors and hospital-level random effects. We used a 2-stage regression model for cost in which the open surgery vs MIS coefficient represented excess costs of open surgery not due to complications, while the complication by open surgery vs MIS interaction and complication terms were used to calculate excess costs due to complications. All costs were in 2010 US dollars.

Using parameters from the regressions, we projected the cost savings, the number of complications avoided, and the number of hospital days avoided based on 2 scenarios in which patients who underwent open surgery were simulated to receive MIS. Scenario 1 was an increase in the use of MIS among hospitals with lower rates of MIS (ie, up to the average use of the top third of hospitals using MIS [83rd percentile]). Scenario 2 was a 50% increase in the use of MIS at all hospitals from baseline.

There was significant variation in average cost by hospital (Figure). Minimally invasive surgery resulted in lower costs than open surgery for all indications (mean savings per discharge for appendectomy, $1528 [95% CI, $1685 to $1370]; for colectomy, $7507 [95% CI, $8197 to $6816]; and for lobectomy, $6290 [95% CI, $7811 to $4769]). Savings attributable to reduced complications alone, with corresponding percentage of savings attributable to reduced complications of total savings, were $688 (43.7% savings) for appendectomy, $5097 (67.9% savings) for colectomy, and $2844 (46.8% savings) for lobetomy. Minimally invasive surgery was associated with a shorter length of hospital stay (−1.4 days [95% CI, −1.5 to −1.3 days] for appendectomy, −3.0 days [95% CI, −3.2 to −2.7 days] for colectomy, and −2.1 days [95% CI, −2.6 to −1.6 days] for lobectomy).

If hospitals increased their use of MIS to that of the top third of hospitals using MIS (scenario 1), then there would be 4306 fewer complications, 169 819 fewer hospital days, and $337 million in annual savings nationwide (Table). If all hospitals increased their use of MIS by 50% from baseline (scenario 2), then the estimated savings would be 3578 fewer complications, 144 853 fewer hospital days, and $288 million in savings. The overall complication rates for these procedures would decrease (scenario 1: from 4.9% to 4.3% for appendectomy, from 28.6% to 27.3% for colectomy, and from 23.0% to 20.2% for lobectomy).

Underuse of MIS represents an opportunity to reduce complication rates and health care costs. Increased rates of MIS would result in up to $280 to $340 million in savings, and that is not including the additional cost savings due to the resulting lower rates of readmissions. Our study is consistent with a previous study⁶ estimating the cost of a general postoperative complication at $11 600 ($14 300 in 2010); however, we found that costs were higher than previous estimates for open colectomy ($25 400) and lung lobectomy ($23 300).

The advent of value-based purchasing and global payment schemes will shift the cost burden of complications from payers to hospitals. Hospitals should consider retraining surgeons and adopting a more appropriate division of labor so that patients who require open surgery are directed to surgeons skilled in open surgery and patients who are candidates for MIS are operated on by surgeons skilled in MIS. A more appropriate use of MIS represents an opportunity for hospitals to improve patient outcomes, report improved publicly reported metrics, and increase profit in global payment systems.

Corresponding Author: Martin A. Makary, MD, MPH, Department of Surgery, Johns Hopkins University School of Medicine, Halsted 610, 600 N Wolfe St, Baltimore, MD 21287 (mmakary1@jhmi.edu).

Published Online: March 25, 2015. doi:10.1001/jamasurg.2014.4052.

Author Contributions: Mr Xu had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Xu, Hutfless, Cooper, Massie, Makary.

Acquisition, analysis, or interpretation of data: Xu, Hutfless, Zhou, Massie.

Drafting of the manuscript: Xu.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: Xu, Hutfless, Zhou, Makary.

Study supervision: Hutfless, Cooper, Massie, Makary.

Conflict of Interest Disclosures: Dr Makary reports receipt of royalties from Bloomsbury Press for publication of a book on medical transparency. No other disclosures are reported.

Additional Contributions: We thank Jiangxia Wang, research associate at the Johns Hopkins School of Public Health, for her assistance in statistical analysis. She was not compensated.