An Instrumental Variable Analysis Comparing Medicare Expenditures for Laparoscopic vs Open Colectomy

Surgical Approach and Long-Term Recurrence After Ventral Hernia Repair

Importance

The prevalence of robotic-assisted anterior abdominal wall (ventral) hernia repair has increased dramatically in recent years, despite conflicting evidence of patient benefit. Whether long-term hernia recurrence rates following robotic-assisted repairs are lower than rates following more established laparoscopic or open approaches remains unclear.

Objective

To evaluate the association between robotic-assisted, laparoscopic, and open approaches to ventral hernia repair and long-term operative hernia recurrence.

Design, Setting, and Participants

Secondary retrospective cohort analysis using Medicare claims data examining adults 18 years and older who underwent elective inpatient ventral, incisional, or umbilical hernia repair from January 1, 2010, to December 31, 2020. Data analysis was performed from January 2023 through March 2024.

Exposure

Operative approach to ventral hernia repair, which included robotic-assisted, laparoscopic, and open approaches.

Main Outcomes and Measures

The primary outcome was operative hernia recurrence for up to 10 years after initial hernia repair. To help account for potential bias from unmeasured patient factors (eg, hernia size), an instrumental variable analysis was performed using regional variation in the adoption of robotic-assisted hernia repair over time as the instrument. Cox proportional hazards modeling was used to estimate the risk-adjusted cumulative incidence of operative recurrence up to 10 years after the initial procedure, controlling for factors such as patient age, sex, race and ethnicity, comorbidities, and hernia subtype (ventral/incisional or umbilical).

Results

A total of 161 415 patients were included in the study; mean (SD) patient age was 69 (10.8) years and 67 592 patients (41.9%) were male. From 2010 to 2020, the proportion of robotic-assisted procedures increased from 2.1% (415 of 20 184) to 21.9% (1737 of 7945), while the proportion of laparoscopic procedures decreased from 23.8% (4799 of 20 184) to 11.9% (946 of 7945) and of open procedures decreased from 74.2% (14 970 of 20 184) to 66.2% (5262 of 7945). Patients undergoing robotic-assisted hernia repair had a higher 10-year risk-adjusted cumulative incidence of operative recurrence (13.43%; 95% CI, 13.36%-13.50%) compared with both laparoscopic (12.33%; 95% CI, 12.30%-12.37%; HR, 0.78; 95% CI, 0.62-0.94) and open (12.74%; 95% CI, 12.71%-12.78%; HR, 0.81; 95% CI, 0.64-0.97) approaches. These trends were directionally consistent regardless of surgeon procedure volume.

Conclusions and Relevance

This study found that the rate of long-term operative recurrence was higher for patients undergoing robotic-assisted ventral hernia repair compared with laparoscopic and open approaches. This suggests that narrowing clinical applications and evaluating the specific advantages and disadvantages of each approach may improve patient outcomes following ventral hernia repairs.

Association between physician-hospital integration and inpatient care delivery in accountable care organizations: An instrumental variable analysis

OBJECTIVE

To investigate the relationship between physician-hospital integration within accountable care organizations (ACOs) and inpatient care utilization and expenditure.

DATA SOURCES

The primary data were Massachusetts All-Payer Claims Database (2009-2013).

STUDY SETTING

Fifteen provider organizations that entered a commercial ACO contract with a major private payer in Massachusetts between 2009 and 2013.

STUDY DESIGN

Using an instrumental variable approach, the study compared inpatient care delivery between patients of ACOs demonstrating high versus low integration. We measured physician-hospital integration within ACOs by the proportion of primary care physicians in an ACO who billed for outpatient services with a place-of-service code indicating employment or practice ownership by a hospital. The study sample comprised non-elderly adults who had continuous insurance coverage and were attributed to one of the 15 ACOs. Outcomes of interest included total medical expenditure during an episode of inpatient care, length of stay (LOS) of the index hospitalization, and 30-day readmission. An inpatient episode was defined as 30, 45, and 60 days from the admission date.

DATA COLLECTION/EXTRACTION METHODS

Not applicable.

PRINCIPAL FINDINGS

The study examined 33,535 admissions from patients served by the 15 ACOs. Average medical expenditure within 30 days of admission was $24,601, within 45 days was $26,447, and within 60 days was $28,043. Average LOS was 3.5 days, and 5.4% of patients were readmitted within 30 days. Physician-hospital integration was associated with a 10.6% reduction in 30-day expenditure (95% CI, -15.1% to -5.9%). Corresponding estimates for 45 and 60 days were - 9.7% (95%CI, -14.2% to -4.9%) and - 9.6% (95%CI, -14.3% to -4.7%). Integration was associated with a 15.7% decrease in LOS (95%CI, -22.6% to -8.2%) but unrelated to 30-day readmission rate.

CONCLUSIONS

Our instrumental variable analysis shows physician-hospital integration with ACOs was associated with reduced inpatient spending and LOS, with no evidence of elevated readmission rates.

Intracorporeal or extracorporeal ileocolic anastomosis after laparoscopic right colectomy: cost analysis of the Torino trial

BACKGROUND

Intracorporeal (IIA) and extracorporeal anastomosis (EIA) are two well-established techniques for restoration of bowel continuity after laparoscopic right colectomy (LRC). Since no economic analysis comparing the two different anastomotic techniques has been performed yet, it is still unclear if IIA can reduce perioperative costs. The aim of the study was to compare costs of LRC with IIA or EIA for right-sided colon neoplasm.

METHODS

This is a cost analysis of a single-institution double-blinded randomized controlled trial comparing the outcomes of LRC with IIA and LRC with EIA in patients with a right-sided colon neoplasm. All direct in-hospital costs related to patient's admission were recorded (intraoperative costs: operative room, surgical tools, blood units-postoperative costs: hospital stay, laboratory and microbiology analyses, diagnostic services, analgesic drugs and antibiotic therapy, blood units, reoperation-outpatient costs: post-discharge wound medications). This trial was registered with ClinicalTrials.gov, Number NCT03045107.

RESULTS

A total of 140 patients were randomized and analyzed. Mean overall costs in the IIA group exceeded 349 € the mean overall costs of the EIA group (7926.87 ± 4617.23 € vs. 7577.45 ± 6131.17 €; P = 0.704). A mean extra charge of 608 € regarding total intraoperative costs was recorded in the IIA group (3058.84 ± 897.42 € vs. 2450.15 ± 558.90 €; P < 0.001). The cost of surgical instruments resulted in 542 € additional charge per patient in the IIA group compared to EIA group (1782.74 ± 541.26 € vs. 1240.55 ± 384.09 €; P < 0.001). The mean cost of operative room occupancy was comparable in IIA and EIA group: 1276.09 ± 514.94 € vs. 1209.60 ± 422.80 € (P = 0.405). No significant differences were observed in postoperative costs and in outpatient costs.

CONCLUSION

This economic analysis showed that IIA and EIA after LRC had similar overall costs, even though there were intraoperative extra costs of IIA.

Laparoscopic Intracorporeal Anastomosis

Given the progression of laparoscopic surgery, questions continue to arise as to the ideal technique for a laparoscopic colectomy. The most debated of these questions is whether it is best to complete an intracorporeal (ICA) or extracorporeal (ECA) intestinal anastomosis. Here, we review the literature to date and report the equivalent safety and efficacy of ICA and ECA for laparoscopic right colectomy. However, these studies also indicate that when completed, ICA may prove beneficial with respect to earlier return of bowel function, less postoperative pain, shorter incision length, and reduced risk of wound infections. For this, we present the tips and tricks for completing all forms of laparoscopic ICAs during laparoscopic colectomy.

Association of Insurance Coverage With Adoption of Sleeve Gastrectomy vs Gastric Bypass for Patients Undergoing Bariatric Surgery

IMPORTANCE

Instrumental variables can control for selection bias in observational research. However, valid instruments are challenging to identify.

OBJECTIVE

To evaluate regional variation in sleeve gastrectomy following insurance coverage implementation as an instrumental variable in comparative effectiveness research.

DESIGN, SETTING, AND PARTICIPANTS

This serial cross-sectional study included adult patients in a national Medicare claims database who underwent sleeve gastrectomy or Roux-en-Y gastric bypass from 2012 to 2017. Data analysis was performed from January to June 2021.

EXPOSURES

Laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass.

MAIN OUTCOMES AND MEASURES

The association of the instrumental variable with treatment (ie, undergoing sleeve gastrectomy), as well as mortality, complications, emergency department visits, hospitalization, reinterventions, and surgical revision.

RESULTS

A total of 76 077 patients underwent bariatric surgery, of whom 44 367 underwent sleeve gastrectomy (mean [SD] age, 56.9 [11.9] years; 32 559 [73.5%] women) and 31 710 underwent gastric bypass (mean (SD) age, 55.9 (11.8) years; 23 750 [74.9%] women). After insurance coverage initiation, there was substantial regional and temporal variation in adoption of sleeve gastrectomy. Prior-year state-level utilization of sleeve gastrectomy was highly associated with undergoing sleeve gastrectomy (Kleibergen-Paap Wald F statistic, 910.3). All but 2 patient characteristics (race and diagnosis of depression) were well-balanced between the top and bottom quartiles of the instrumental variable. Regarding 1-year outcomes, compared with patients undergoing gastric bypass, patients undergoing sleeve gastrectomy had a lower 1-year risk of mortality (0.9%; 95% CI, 0.8%-1.1% vs 1.7%; 95% CI, 1.3%-2.0%), complications (11.6%; 95% CI, 10.9%-12.3% vs 14.1%; 95% CI, 13.0%-15.3%), emergency department visits (48.3%; 95% CI, 46.9%-49.8% vs 53.6%; 95% CI, 52.3%-55.0%), hospitalization (23.4%; 95% CI, 22.4%-24.4% vs 26.5%; 95% CI, 25.1%-28.0%), and reinterventions (8.7%; 95% CI, 8.0%-9.4% vs 12.2%; 95% CI, 11.2%-13.3%). The risk of revision was not different between groups (0.6%; 95% CI, 0.3%-0.8% vs 0.4%; 95% CI, 0.3%-0.6%).

CONCLUSIONS AND RELEVANCE

In this cross-sectional study of patients undergoing bariatric surgery, there was significant geographic variation in the use of sleeve gastrectomy following initiation of insurance coverage, which served as a strong instrument to compare 2 bariatric surgical procedures. This approach could be applied to other areas of health services research to serve as a complement to clinical trials.

Primary tumor resection with or without metastasectomy for left- and right-sided stage IV colorectal cancer: an instrumental variable analysis

BACKGROUND

Whether primary tumor location (PTL) is predictive of survival benefits following primary tumor resection plus metastasectomy (PMTR) and primary tumor resection (PTR) alone in stage IV colorectal cancer patients is not known. We sought to address this issue by employing instrumental variable analysis to evaluate the efficacy of PMTR and PTR with stratification for primary tumor location in stage IV colorectal cancer patients.

PATIENTS AND METHODS

Stage IV colorectal cancer patients diagnosed between January 1, 2005 and December 31, 2015 were identified from the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute. To account for both measured and unmeasured confounders, the efficacy of PMTR and PTR in the left- and right-sided subgroups was evaluated using instrumental variable analysis, with the health service area as the instrument variable. Overall survival (OS) was the primary outcome of interest.

RESULTS

A total of 50,333 eligible patients were analyzed (left-sided, n = 29,402 and right-sided, n = 20,931). OS was significantly better with PMTR than with other treatments (PTR, metastasectomy only, or no surgery) in patients with left-sided tumors (hazard ratio [HR] = 0.37 [95% CI 0.24-0.58], P < 0.001), but not in patients with right-sided tumors (HR = 0.98 [95% CI 0.65-1.47], P = 0.910; interaction test P < 0.001). OS was comparable in patients treated with PTR and those treated with no surgery in both the left-sided (HR = 1.11 [95% CI 0.68-1.81], P = 0.690) and right-sided (HR = 0.85 [95% CI 0.50-1.43], P = 0.530; interaction test P = 0.466) subgroups.

CONCLUSIONS

PMTR appears to only benefit patients with left-sided stage IV colorectal cancer but not those with right-sided tumors. PTR does not improve OS, regardless of primary tumor location. When selecting patients for PMTR, primary tumor location should be considered. Overuse of PTR should be avoided.

Comparative effectiveness of stereotactic body radiation therapy versus surgery for stage I lung cancer in otherwise healthy patients: An instrumental variable analysis

Objectives

Stereotactic body radiation therapy (SBRT) is an established primary treatment modality in patients with lung cancer who have multiple comorbidities and/or advanced-stage disease. However, its role in otherwise healthy patients with stage I lung cancer is unclear. In this context, we compared the effectiveness of SBRT versus surgery on overall survival using a national database.

Methods

We identified all patient with clinical stage I non–small cell lung cancer from the National Cancer Database from 2004 to 2016. We defined otherwise healthy patients as those with a Charlson-Deyo comorbidity index of 0 and whose treatment plan included options for either SBRT or surgery. We further excluded patients who received SBRT due to a contraindication to surgery. We first used propensity score matching and Cox proportional hazard models to identify associations. Next, we fit 2-stage residual inclusion models using an instrumental variables approach to estimate the effects of SBRT versus surgery on long-term survival. We used the hospital SBRT utilization rate as the instrument.

Results

Of 25,963 patients meeting all inclusion/exclusion criteria, 5465 (21%) were treated with SBRT. On both Cox proportional hazards modeling and propensity-score matched Kaplan-Meier analysis, surgical resection was associated with improved survival relative to SBRT. In the instrumental-variable–adjusted model, SBRT remained associated with decreased survival (hazard ratio, 2.64; P < .001). Both lobectomy (hazard ratio, 0.17) and sublobar resections (hazard ratio, 0.28) were associated with improved overall survival compared with SBRT (P < .001).

Conclusions

In otherwise healthy patients with stage I NSCLC, surgical resection is associated with a survival benefit compared with SBRT. This is true for both lobar and sublobar resections.

Comparison of health-care utilization and expenditures for minimally invasive vs. open colectomy for benign disease

BACKGROUND

Adoption of minimally invasive approaches continues to increase, and there is a need to reassess outcomes and cost. We aimed to compare open versus minimally invasive colectomy short- and long-term health-care utilization and payer/patient expenditures for benign disease.

METHODS

This is a retrospective analysis of IBM^® MarketScan^® Database patients who underwent left or right colectomy for benign disease between 2013 and 2018. Outcomes included total health-care expenditures, resource utilization, and direct workdays lost up to 365 days following colectomy. The open surgical approach (OS) was compared to minimally invasive colectomy (MIS) with subgroup analysis of laparoscopic (LS) and robotic (RS) approaches using inverse probability of treatment weighting.

RESULTS

Of 10,439 patients, 2531 (24.3%) had open, 6826 (65.4%) had laparoscopic, and 1082 (10.3%) had robotic colectomy. MIS patients had shorter length of stay (LOS; mean difference, - 1.71, p < 0.001) and lower average total expenditures (mean difference, - $2378, p < 0.001) compared with open patients during the index hospitalization. At 1 year, MIS patients had lower readmission rates, and fewer mean emergency and outpatient department visits than open patients, translating into additional savings of $5759 and 2.22 fewer days missed from work for health-care visits over the 365-day post-discharge period. Within MIS, RS patients had shorter LOS (mean difference, - 0.60, p < 0.001) and lower conversion-to-open rates (odds ratio, 0.31 p < 0.001) during the index hospitalization, and lower hospital outpatient visits (mean difference, - 0.31, p = 0.001) at 365 days than LS.

CONCLUSION

MIS colectomy is associated with lower mean health-care expenditures and less resource utilization compared to the open approach for benign disease at index operation and 365-days post-discharge. Health-care expenditures for LS and RS are similar but shorter mean LOS and lower conversion-to-open surgery rates were observed at index operation for the RS approach.

Healthcare Funding Decisions and Real-World Benefits: Reducing Bias by Matching Untreated Patients

Governments and health insurers often make funding decisions based on health gains from randomised controlled trials. These decisions are inherently uncertain because health gains in trials may not translate to practice owing to differences in the population, treatment use and setting. Post-market analysis of real-world data can provide additional evidence but estimates from standard matching methods may be biased when unobserved characteristics explain whether a patient is treated and their outcomes. We propose a new untreated matching approach that can reduce this bias. Our approach utilises the outcomes of contemporaneous untreated patients to improve the matching of treated and historical control patients. We assess the performance of this new approach compared to standard matching using a simulation study and demonstrate the steps required using a funding decision for prostate cancer treatments in Australia. Our simulation study shows that our new matching approach eliminates nearly all bias when unobserved treatment selection is related to outcomes, and outperforms standard matching in most scenarios. In our empirical example, standard matching overestimated survival by 15% (95% confidence interval 2-34) compared to our untreated matching approach. The health gains estimated using our approach were slightly lower than expected based on the trial evidence, but we also found evidence that in practice prescribers ceased prior therapies earlier, treated a more vulnerable population and continued treatment for longer. Our untreated matching approach offers researchers a new tool for reducing uncertainty in healthcare funding decisions using real-world data.

Perioperative Outcomes and Trends in the Use of Robotic Colectomy for Medicare Beneficiaries From 2010 Through 2016

Importance

The use of robotic surgery for common operations like colectomy is increasing rapidly in the United States, but evidence for its effectiveness is limited and may not reflect real-world practice.

Objective

To evaluate outcomes of and trends in the use of robotic, laparoscopic, and open colectomy across diverse practice settings.

Design, Setting, and Participants

This population-based study of Medicare beneficiaries undergoing elective colectomy was conducted between January 2010 and December 2016. We used an instrumental variable analysis to account for both measured and unmeasured differences in patient characteristics between robotic, open, and laparoscopic colectomy procedures. Data were analyzed from January 21, 2019, to March 1, 2019.

Exposures

Receipt of robotic colectomy.

Main Outcomes and Measures

Incidence of postoperative medical and surgical complications and length of stay.

Results

A total of 191 292 procedures (23 022 robotic procedures [12.0%], 87 639 open procedures [45.8%], and 80 631 laparoscopic colectomy procedures [42.0%]) were included. Robotic colectomy was associated with a lower adjusted rate of overall complications than open colectomy (17.6% [95% CI, 16.9%-18.2%] vs 18.6% [95% CI, 18.4%-18.7%]; relative risk [RR], 0.94 [95% CI, 0.91-0.98]). This difference was driven by lower rates of medical complications (15.5% [95% CI, 14.8%-16.2%] vs 16.9% [95% CI, 16.7%-17.1%]; RR, 0.92 [95% CI, 0.87-0.96]) because surgical complications were higher with the robotic approach (3.0% [95% CI, 2.8%-3.2%] vs 2.4% [95% CI, 2.3%-2.5%]; RR, 1.18 [95% CI, 1.04-1.35]). There were no differences in complications between robotic and laparoscopic colectomy (11.1% [95% CI, 10.5%-11.6%] vs 11.0% [95% CI, 10.8%-11.2%]; RR, 1.00 [95% CI, 0.95-1.05]). There was an overall shift toward greater proportional use of robotic colectomy from 0.7% (457 of 65 332 patients) in 2010 to 10.9% (8274 of 75 909 patients) in 2016. In hospitals with the highest adoption of robotic colectomy between 2010 and 2016, increasing use of robotic colectomy (0.8% [100 of 12 522 patients] to 32.8% [5416 of 16 511 patients]) was associated with a greater replacement of laparoscopic operations (43.8% [5485 of 12 522 patients] to 25.2% [4161 of 16 511 patients]) than open operations (55.4% [6937 of 12 522 patients] to 41.9% [6918 of 16 511 patients]).

Conclusions and Relevance

While robotic colectomy was associated with minimal safety benefit over open colectomy and had comparable outcomes with laparoscopic colectomy, population-based trends suggest that it replaced a greater proportion of laparoscopic rather than open colectomy, especially in hospitals with the highest adoption of robotics.

Association of Depression with In-Patient and Post-Discharge Disposition and Expenditures Among Medicare Beneficiaries Undergoing Resection for Cancer

BACKGROUND

The impact of depression on utilization of post-discharge care and overall episode of care expenditures remains poorly defined. We sought to define the impact of depression on postoperative outcomes, including discharge disposition, as well as overall expenditures associated with the global episode of surgical care.

METHOD

The Medicare 100% Standard Analytic Files were used to identify patients undergoing resection for esophageal, colon, rectal, pancreatic, and liver cancer between 2013 and 2017. The impact of depression on inpatient outcomes, as well as home health care and skilled nursing facilities utilization and expenditures, was analyzed.

RESULTS

Among 113,263 patients, 14,618 (12.9%) individuals had depression. Patients with depression were more likely to experience postoperative complications (odds ratio [OR] 1.36, 95% confidence interval [CI] 1.31-1.42), extended length of stay (LOS) (OR 1.41, 95% CI 1.36-1.47), readmission within 90 days (OR 1.20, 95% CI 1.14-1.25), as well as 90-day mortality (OR 1.35, 95% CI 1.27-1.42) (all p < 0.05). In turn, the proportion of patients who achieved a textbook outcome following cancer surgery was lower among patients with depression (no depression: 53.3% vs. depression: 45.3%; OR 0.70, 95% CI 0.68-0.73). Patients with a preexisting diagnosis of depression had higher odds of additional post-discharge expenditures compared with individuals without a diagnosis of depression (OR 1.42; 95% CI 1.35-1.50); patients with a preexisting diagnosis of depression ($10,500, IQR $3,200-$22,500) had higher median post-discharge expenditures versus patients without depression ($6600, IQR $2100-$17,400) (p < 0.001). On multivariable analysis, after controlling for other factors, depression remained associated with a 19.0% (95% confidence interval [CI] 15.7-22.3%) increase in post-discharge expenditures.

CONCLUSIONS

Patients with depression undergoing resection for cancer had worse in-patient outcomes and were less likely to achieve a TO. Patients with depression were more likely to require post-discharge care and had higher post-discharge expenditures.

Procedural episode-based cost measures: anesthesia matters

PURPOSE OF REVIEW

Episode-based cost measures (EBCM) is a method of combining all services related to a defined episode of care, identified as either a procedure, acute illness or chronic disease, and providing expected cost for that episode or bundle of care. Procedural EBCM has become a major scheme for payment methodology and patient quality of care evaluation. Anesthesiologists need to know how EBCM can impact their clinical practice.

RECENT FINDING

Centers for Medicare and Medicaid Services (CMS) pays physicians with fee-for-service payment for Clinical Episodes and, in 2020, the EBCM are increasing and currently, represents 4.5% of the total Medicare Part A and B spending [1]. With the recent changes in CMS, it is important, for anesthesia providers to know how cost attribution identifies the cost for all services and complications under anesthetic management.

SUMMARY

EBCM can impact the anesthesiologist's quality performance, efficiencies measures, and payment. To preserve practice viability, anesthesiologists must understand how their compensation is impacted by services ordered. Anesthesiologists will increasingly be expected to improve quality and efficiencies in EBCM.

Medicare Accountable Care Organizations and the Adoption of New Surgical Technology

BACKGROUND

Dissemination of new surgical technology is a major contributor to healthcare spending growth. Accountable care organization (ACO) policy aims to control spending while maintaining quality. As a result, ACOs provide incentive for hospitals to selectively adopt newer procedures with high value.

STUDY DESIGN

We conducted a retrospective cohort study using a 20% sample of national Medicare claims from 2010 to 2015. We identified hospitals that performed 1 of 6 sets of procedures: abdominal aortic aneurysm repair, aortic valve replacement, carotid endarterectomy or stent, lung lobectomy, colectomy, and prostatectomy. We identified hospitals participating in a Medicare Shared Savings Program ACO and a set of matched non-ACO control hospitals. We used a difference-in-differences approach to compare rate of surgical treatment and use of newer surgical technology for each set of procedures in ACO and non-ACO hospitals.

RESULTS

We included 707 ACO-hospitals and 1,770 control hospitals. ACO hospitals performed surgery for carotid stenosis at a lower rate than non-ACO hospitals. There was no difference in the rate of surgical treatment for all other procedure sets. ACO hospitals were less likely to use an endovascular approach for abdominal aortic aneurysm repair (85.2% vs 88.2%, p < 0.001) and more likely to use a minimally invasive approach for lung lobectomy (42.2% vs 34.7%, p = 0.004) than non-ACO hospitals. In difference-in-differences analysis, ACO participation was not associated with any significant difference in use of surgical care for any of the 6 procedure sets, nor with any significant difference in use of newer surgical technology.

CONCLUSIONS

Despite ACO policy incentives to selectively adopt newer surgical technology, ACO participation was not associated with differences in rate of surgery or use of newer surgical technology for 6 major surgical procedures.

Cost-effectiveness analysis of laparoscopic and open surgery in routine Swedish care for colorectal cancer

BACKGROUND

Laparoscopic surgery for colorectal cancer has been shown in clinical trials to be effective regarding short-term outcomes and oncologically safe. Health economic analyses have been performed early in the learning curve when adoption of laparoscopic surgery was not extensive. This cost-effectiveness analysis evaluates laparoscopic versus open colorectal cancer surgery in Swedish routine care.

METHODS

In this national retrospective cohort study, data were retrieved from the Swedish ColoRectal Cancer Registry. Clinical effectiveness, resource use and unit costs were derived from this and other sources with nationwide coverage. The study period was 2013 and 2014 with 1 year follow-up. Exclusion criterion comprised cT4-tumors. Clinical effectiveness was estimated in a composite endpoint of all-cause resource-consuming events in inpatient care, readmissions and deaths up to 90 days postoperatively. Up to 1 year, events predefined as related to the primary surgery were included. Costs included resource-consuming events, readmissions and sick leave and were estimated for both the society and healthcare. Multivariable regression analyses were used to adjust for differences in baseline characteristics between the groups.

RESULTS

After exclusion of cT4 tumors, the cohort included 7707 patients who underwent colorectal cancer surgery: 6060 patients in the open surgery group and 1647 patients in the laparoscopic group. The mean adjusted difference in clinical effectiveness between laparoscopic and open colorectal cancer surgery was 0.23 events (95% CI 0.12 to 0.33). Mean adjusted differences in costs (open minus laparoscopic surgery) were $4504 (95% CI 2257 to 6799) and $4480 (95% CI 2739 to 6203) for the societal and the healthcare perspective respectively. In both categories, resource consuming events in inpatient care were the main driver of the results.

CONCLUSION

In a national cohort, laparoscopic colorectal cancer surgery was associated with both superior outcomes for clinical effectiveness and cost versus open surgery.

Effects of laparoscopic vs open abdominal surgery on costs and hospital readmission rate and its effect modification by surgeons' case volume

BACKGROUND

Laparoscopy provides a minimally invasive alternative to open abdominal surgery. Current data describing its association with hospital readmission and costs in relation to surgeon laparoscopic case volume is limited to smaller databases and subsets of operations.

METHODS

This retrospective cohort study of 23,285 adult abdominal operations from 2007 to 2015 compares 30-day readmission rate and costs between laparoscopic and open abdominal operations and examines effect modification by surgeon laparoscopic case volume. Outcomes were all-cause hospital readmission within 30 days after discharge and index hospital admission cost.

RESULTS

All-cause hospital readmission rates were significantly lower after laparoscopic abdominal operations compared with open operations (adjusted odds ratio [aOR] 0.56, 95% CI 0.46-0.69, p < 0.001) with a difference in readmission risk attributable to laparoscopic approach of - 4.0% (95% CI - 5.4 to - 2.6%) in complete-case analysis. Among surgeons with a high laparoscopic case volume, the estimated difference in readmission risk through laparoscopy was magnified (- 5.8%, 95% CI - 7.5 to - 4.1%) compared to low surgeon laparoscopic case volume (- 2.9%, 95% CI - 4.8 to -1.1%, p for interaction = 0.005). The estimated difference in costs of the index hospital admission attributable to laparoscopic approach was - $3869 (95% CI - $4200 to - $3538; adjusted incidence rate ratio 0.77, 95% CI 0.75-0.79, p < 0.001). Laparoscopy was followed by significantly lower rates of readmissions related to gastrointestinal (aOR 0.68, 95% CI 0.55-0.85, p = 0.001), wound complications (infection: aOR 0.33, 95% CI 0.23-0.47, p < 0.001; non-infectious: aOR 0.47, 95% CI 0.30-0.74, p = 0.001), and malignancy (aOR 0.68, 95% CI 0.55-0.85, p < 0.001). The findings remain robust after multiple imputation and sensitivity analyses.

CONCLUSIONS

Laparoscopy versus open abdominal surgery is associated with reduced hospital readmissions related to malignancy, gastrointestinal, and wound complications. Effect modification by higher laparoscopy case volume argues for continued proliferation of laparoscopy in abdominal surgeries.

Novel Machine Learning Approach to Identify Preoperative Risk Factors Associated With Super-Utilization of Medicare Expenditure Following Surgery

Importance

Typically defined as the top 5% of health care users, super-utilizers are responsible for an estimated 40% to 55% of all health care costs. Little is known about which factors may be associated with increased risk of long-term postoperative super-utilization.

Objective

To identify clusters of patients with distinct constellations of clinical and comorbid patterns who may be associated with an elevated risk of super-utilization in the year following elective surgery.

Design, Setting, and Participants

A retrospective longitudinal cohort study of 1 049 160 patients who underwent abdominal aortic aneurysm repair, coronary artery bypass graft, colectomy, total hip arthroplasty, total knee arthroplasty, or lung resection were identified from the 100% Medicare inpatient and outpatient Standard Analytic Files at all inpatient facilities performing 1 or more of the evaluated surgical procedures from 2013 to 2015. Data from 2012 to 2016 were used to evaluate expenditures in the year preceding and following surgery. Using a machine learning approach known as Logic Forest, comorbidities and interactions of comorbidities that put patients at an increased chance of becoming a super-utilizer were identified. All comorbidities, as defined by the Charlson (range, 0-24) and Elixhauser (range, 0-29) comorbidity indices, were used in the analysis. Higher scores indicated higher comorbidity burden. Data analysis was completed on November 16, 2018.

Main Outcome and Measures

Super-utilization of health care in the year following surgery.

Results

In total, 1 049 160 patients met inclusion criteria and were included in the analytic cohort. Their median (interquartile range) age was 73 (69-78) years, and approximately 40% were male. Super-utilizers comprised 4.8% of the overall cohort (n = 79 746) yet incurred 31.7% of the expenditures. Although the difference in overall expenditures per person between super-utilizers ($4049) and low users ($2148) was relatively modest prior to surgery, the difference in expenditures between super-utilizers ($79 698) vs low users ($2977) was marked in the year following surgery. Risk factors associated with super-utilization of health care included hemiplegia/paraplegia (odds ratio, 5.2; 95% CI, 4.4-6.2), weight loss (odds ratio, 3.5; 95% CI, 2.9-4.2), and congestive heart failure with chronic kidney disease stages I to IV (odds ratio, 3.4; 95% CI, 3.0-3.9).

Conclusions and Relevance

Super-utilizers comprised only a small fraction of the surgical population yet were responsible for a disproportionate amount of Medicare expenditure. Certain subpopulations were associated with super-utilization of health care following surgical intervention despite having lower overall use in the preoperative period.

Patients with a Ruptured Abdominal Aortic Aneurysm Are Better Informed in Hospitals with an "EVAR-preferred" Strategy: An Instrumental Variable Analysis of the Dutch Surgical Aneurysm Audit

BACKGROUND

While several observational studies suggested a lower postoperative mortality after minimal invasive endovascular aneurysm repair (EVAR) in patients with a ruptured abdominal aortic aneurysm (RAAA) compared to conventional open surgical repair (OSR), landmark randomized controlled trials have not been able to prove the superiority of EVAR over OSR. Randomized controlled trials contain a selected, homogeneous population, influencing external validity. Observational studies are biased and adjustment of confounders can be incomplete. Instrumental variable (IV) analysis (pseudorandomization) may help to answer the question if patients with an RAAA have lower postoperative mortality when undergoing EVAR compared to OSR.

METHODS

This is an observational study including all patients with an RAAA, registered in the Dutch Surgical Aneurysm Audit between 2013 and 2017. The risk difference (RD) in postoperative mortality (30 days/in-hospital) between patients undergoing EVAR and OSR was estimated, in which adjustment for confounding was performed in 3 ways: linear model adjusted for observed confounders, propensity score model (multivariable logistic regression analysis), and IV analysis (two-stage least square regression), adjusting for observed and unobserved confounders, with the variation in percentage of EVAR per hospital as the IV instrument.

RESULTS

2419 patients with an RAAA (1489 OSR and 930 EVAR) were included. Unadjusted postoperative mortality was 34.9% after OSR and 22.6% after EVAR (RD 12.3%, 95% CI 8.5-16%). The RD adjusted for observed confounders using linear regression analysis and propensity score analysis was, respectively, 12.3% (95% CI 9.6-16.7%) and 13.2% (95%CI 9.3-17.1%) in favor of EVAR. Using IV analysis, adjusting for observed and unobserved confounders, RD was 8.9% (95% CI -1.1-18.9%) in favor of EVAR.

CONCLUSIONS

Adjusting for observed confounders, patients with an RAAA undergoing EVAR had a significant better survival than OSR in a consecutive large cohort. Adjustment for unobserved confounders resulted in a clinical relevant RD. An "EVAR preference strategy" in patients with an RAAA could result in lower postoperative mortality.

Liver Resection Improves Survival in Colorectal Cancer Patients: Causal-effects From Population-level Instrumental Variable Analysis

OBJECTIVE

The aim of this study was to estimate population-level causal effects of liver resection on survival of patients with colorectal cancer liver metastases (CRC-LM).

BACKGROUND

A randomized trial to prove that liver resection improves survival in patients with CRC-LM is neither feasible nor ethical. Here, we test this assertion using instrumental variable (IV) analysis that allows for causal-inference by controlling for observed and unobserved confounding effects.

METHODS

We abstracted data on patients with synchronous CRC-LM using the California Cancer Registry from 2000 to 2012 and linked the records to the Office of Statewide Health Planning and Development Inpatient Database. We used 2 instruments: resection rates in a patient's neighborhood (within 50-mile radius)-NALR rate; and Medical Service Study Area resection rates-MALR rate. IV analysis was performed using the 2SLS method.

RESULTS

A total of 24,828 patients were diagnosed with stage-IV colorectal cancer of which 16,382 (70%) had synchronous CRC-LM. Liver resection was performed in 1635 (9.8%) patients. NALR rates ranged from 8% (lowest-quintile) to 11% (highest-quintile), whereas MALR rates ranged from 3% (lowest quintile) to 19% (highest quintile). There was a strong association between instruments and probability of liver resection (F-statistic at median cut-off: NALR 24.8; MALR 266.8; P < 0.001). IV analysis using both instruments revealed a 23.6 month gain in survival (robust SE 4.4, P < 0.001) with liver resection for patients whose treatment choices were influenced by the rates of resection in their geographic area (marginal patients), after accounting for measured and unmeasured confounders.

CONCLUSION

Less than 10% of patients with CRC-LM had liver resection. Significant geographic variation in resection rates is attributable to community biases. Liver resection leads to extensive survival benefit, accounting for measured and unmeasured confounders.

Cost-effectiveness Evaluation of Targeted Surgical and Endoscopic Therapies for Early Colorectal Adenocarcinoma Based on Biomarker Profiles

IMPORTANCE

Colorectal cancer (CRC) is the second leading cause of cancer-related mortality in the United States. The prognosis for patients with CRC varies widely, but new prognostic biomarkers provide the opportunity to implement a more individualized approach to treatment selection.

OBJECTIVE

To assess the cost-effectiveness of 3 therapeutic strategies, namely, endoscopic therapy (ET), laparoscopic colectomy (LC), and open colectomy (OC), for patients with T1 CRC with biomarker profiles that prognosticate varying levels of tumor progression in the US payer perspective.

DESIGN, SETTING, AND PARTICIPANTS

In this economic evaluation study, a Markov model was developed for the cost-effectiveness analysis. Risks of all-cause mortality and recurrent cancer after ET, LC, or OC were estimated with a 35-year time horizon. Quality of life was based on EuroQoL 5 Dimensions scores reported in the published literature. Hospital and treatment costs reflected Medicare reimbursement rates. Deterministic and probabilistic sensitivity analyses were performed. Data from patients with T1 CRC and 6 biomarker profiles that included adenomatous polyposis coli (APC), TP53 and/or KRAS, or BRAFV600E were used as inputs for the model. Data analyses were conducted from February 27, 2019, to May 13, 2019.

EXPOSURES

Endoscopic therapy, LC, and OC.

MAIN OUTCOMES AND MEASURES

The primary outcomes were unadjusted life-years, quality-adjusted life-years (QALYs), and the incremental cost-effectiveness ratio (ICER) between competing treatment strategies.

RESULTS

Endoscopic therapy had the highest QALYs and the lowest cost and was the dominant treatment strategy for T1 CRC with the following biomarker profiles: BRAFV600E, APC(1)/KRAS/TP53, APC(2) or APC(2)/KRAS or APC(2)/TP53, or APC(1) or APC(1)/KRAS or APC(1)/TP53. The QALYs gained ranged from 16.97 to 17.22, with costs between $68 902.75 and $77 784.53 in these subgroups. For the 2 more aggressive biomarker profiles with worse prognoses (APC(2)/KRAS/TP53 and APCwt [wild type]), LC was the most effective strategy (with 16.45 and 16.61 QALYs gained, respectively) but was not cost-effective. Laparoscopic colectomy cost $65 234.87 for APC(2)/KRAS/TP53 and $71 250.56 for APCwt, resulting in ICERs of $113 290 per QALY and $178 765 per QALY, respectively.

CONCLUSIONS AND RELEVANCE

This modeling analysis found that ET was the most effective strategy for patients with T1 CRC with less aggressive biomarker profiles. For patients with more aggressive profiles, LC was more effective but was costly, rendering ET the cost-effective option. This study highlights the potential utility of prognostic biomarkers in T1 CRC treatment selection.

Is Annual Preoperative Utilization an Indicator of Postoperative Surgical Outcomes? A Study in Medicare Expenditure

INTRODUCTION

Data on the association of high preoperative healthcare utilization and adverse clinical outcomes are scarce. We sought to evaluate the role of annual preoperative expenditure (APE) as a surrogate for latent variables of risk for adverse short-term postoperative outcomes.

METHODS

Low and super-utilizers who underwent abdominal aortic aneurysm repair, coronary artery bypass graft, colectomy, total hip arthroplasty, total knee arthroplasty, or lung resection between 2013 and 2015 were identified from 100% Medicare Inpatient Standard Analytic Files. To assess the association between APE and postoperative outcomes, multivariable logistic regression was utilized.

RESULTS

Among 1,049,160 patients, 788,488 (75.1%) and 21,700 (2.1%) patients were preoperative low- and super-utilizers, respectively. Median APE was more than 60 times higher among super-utilizers than low-utilizers ($57,160 vs. $932), as was the cost of the surgical episode ($21,141 vs. $13,179). The predictive ability of APE ranged from 0.683 (95% CI 0.678-0.687) for 90-day readmission to 0.882 (95% CI 0.879-0.886) for a complication at the index hospitalization. Among super-utilizers, the odds of a complication during the surgical episode was nearly double versus low-utilizers (OR = 1.96, 95% CI 1.89-2.04). Super-utilizers also had an increased odds of 30-day readmission (OR = 1.64, 95% CI 1.58-1.69) and mortality (OR = 2.22; 95% CI 2.04-2.42).

CONCLUSION

APE was able to predict adverse postsurgical outcomes including complications during the surgical episode, readmission, and 90-day mortality. APE should be considered in the assessment of patient populations when defining risk of adverse postoperative events.

Factors associated with switching between low and super utilization in the surgical population: A study in medicare expenditure

BACKGROUND

Considered the top 5% of healthcare utilizers, "super-utilizers" are estimated to consume as much as 40-55% of all healthcare costs. The aim of this study was to identify factors associated with switching between low- and super-utilization.

METHODS

Low and super-utilizers who underwent abdominal aortic aneurysm (AAA) repair, coronary artery bypass graft (CABG), colectomy, total hip arthroplasty (THA), total knee arthroplasty (TKA), or lung resection between 2013 and 2015 were identified from 100% Medicare Inpatient Standard Analytic Files.

RESULTS

Among 1,049,160 patients, 788,488 (75.1%) and 21,700 (2.1%) patients were low- or super-utilizers prior to surgery, respectively. Among patients who were super-utilizers before surgery, 23% remained super-utilizers post-operatively, yet 26.8% patients became low-utilizers after surgery. Factors associated with moving from low-to super-utilization in the pre-versus post-operative setting included AAA repair, higher Charlson, and pulmonary failure. In contrast, pre-operative super-utilizers who became low-utilizers in the post-operative setting were less likely to be African American or have undergone CABG.

CONCLUSION

While 3% of pre-operative low-utilizers became super-utilizers likely due to complications, nearly one quarter of all pre-operative super-utilizers became low-utilizers following surgery suggesting success of the surgery to resolve underlying conditions associated with preoperative super-utilization.

Drivers of Inpatient Costs After Colorectal Surgery Within a Publicly Funded Healthcare System

BACKGROUND

The morbidity and mortality associated with colorectal resections are responsible for significant healthcare use. Identification of efficiencies is vital for decreasing healthcare cost in a resource-limited system.

OBJECTIVE

The purpose of this study was to characterize the short-term cost associated with all colon and rectal resections.

DESIGN

This was a population-based, retrospective administrative analysis.

SETTINGS

This analysis was composed of all colon and rectal resections with anastomosis in Canada (excluding Quebec) between 2008 and 2015.

PATIENTS

A total of 108,304 patients ≥18 years of age who underwent colon and/or rectal resections with anastomosis were included.

MAIN OUTCOME MEASURES

Total short-term inpatient cost for the index admission and the incremental cost of each comorbidity and complication (in 2014 Canadian dollars) were measured. Cost predictors were modeled using hierarchical linear regression and Monte Carlo Markov Chain estimation.

RESULTS

Multivariable regression demonstrated that the adjusted average cost of a 50-year-old man undergoing open colon resection for benign disease with no comorbidities or complications was $9270 ((95% CI, $7146-$11,624; p = <0.001). With adjustment for complications, laparoscopic colon resections carried a cost savings of $1390 (95% CI, $1682-$1099; p = <0.001) compared with open resections. Surgical complications were the main driver for increased cost, because anastomotic leaks added $9129 (95% CI, $8583-$9670; p = <0.001). Medical complications such as renal failure requiring dialysis ($16,939 (95% CI, $15,548-$18,314); p = <0.001) carried significant cost. Complications requiring reoperation cost $16,313 (95% CI, $15,739-$16,886; p = <0.001). The costliest complication cumulatively was reoperation, which exceeded $95 million dollars over the course of the study.

LIMITATIONS

Inherent biases associated with administrative databases limited this study.

CONCLUSIONS

Medical and surgical complications (especially those requiring reoperation) are major drivers of increased resource use. Laparoscopic colorectal resection with or without adjustment for complications carries a clear cost advantage. There is opportunity for considerable cost savings by reducing specific complications or by preoperatively optimizing select patients susceptible to costly complication. See Video Abstract at http://links.lww.com/DCR/A839.

How Patient Complexity and Surgical Approach Influence Episode-Based Payment Models for Colectomy

BACKGROUND

Bundled payment programs broaden hospitals' responsibility for spending to entire episodes of care. After demonstration programs in cardiac surgery and joint replacement, these payment reforms could soon extend to major operations like colectomy under Medicare's Bundled Payments for Care Improvement - Advanced Model.

OBJECTIVE

This study aims to evaluate how specific policies and surgical practice patterns would influence hospital reimbursement in a bundled payment program for colectomy.

DESIGN

This was a population-based study.

SETTINGS

We used national data from the 100% Medicare Provider Analysis and Review files for the years 2010 to 2014.

PATIENTS

We identified patients undergoing colon resections by using diagnosis-related group codes and International Classification of Diseases, Ninth Revision, Clinical Modification codes.

MAIN OUTCOME MEASURES

We simulated per case reconciliation payments as the difference between actual price-standardized 90-day episode payments and estimated regional spending benchmarks among fee-for-service Medicare beneficiaries undergoing colectomy (2010-2014).We projected per patient and overall hospital-level reconciliation payments and the proportion of hospitals that would achieve shared savings under bundled payment conditions. We also assessed how variation in the use of laparoscopy could influence shared savings, using instrumental variable methods to account for selection bias between laparoscopic and open procedures.

RESULTS

Under simulated bundled payment conditions, 51.8% of hospitals would achieve shared savings, but the average case would incur a reconciliation penalty of -$234 (95% CI, -$245 to -$223). Risk adjustment would increase the proportion of hospitals with shared savings to 54.3% (per case payment, +$237; 95% CI, $96-$379). Hospitals performing a greater proportion of cases laparoscopically would achieve higher per case reconciliation payments. For example, per case reconciliation penalties would be -$472 (95% CI, -$506 to -$438) for hospitals that performed 10% of their procedures laparoscopically, whereas those that performed 70% laparoscopically would receive payments of +$294 (95% CI, $262-$326).

LIMITATIONS

Alternative payment models for colectomy have not yet been introduced.

CONCLUSIONS

Surgical leaders must be prepared with strategies for optimizing episode efficiency. Inclusion of risk adjustment in bundled payment calculations and expanding utilization of laparoscopic surgery may represent approaches to achieve shared savings and improve surgeon engagement in alternative payment models for surgical care. See Video Abstract at http://links.lww.com/DCR/A928.

Real-World Impact of Minimally Invasive Versus Open Radical Cystectomy on Perioperative Outcomes and Spending

OBJECTIVE

To evaluate the effect of the minimally invasive approach on spending and perioperative outcomes for patients undergoing radical cystectomy for bladder cancer. In a randomized control trial conducted at high-volume centers, robotic, and open cystectomy were shown to have similar outcomes. However, because the majority of cystectomies are performed in low-volume centers, it is unknown whether these findings are broadly generalizable.

MATERIALS AND METHODS

We identified Medicare patients who underwent radical cystectomy for bladder cancer between 2008 and 2015. We examined the length of stay, readmission rate, and 90-day spending after minimally invasive or open cystectomy. We used multiple regressions to estimate the association between minimally invasive surgery and the outcomes, accounting for patient, hospital, and surgeon factors that may influence these outcomes.

RESULTS

Of 4760 patients, 693 (14.6%) underwent minimally invasive cystectomy and 4067 (85.4%) had an open approach. Minimally invasive cystectomy was associated with shorter length of stay (10.1 days vs 11.9 days, P <.001), but no difference in readmission rate (27.4% vs 26.8%, P = .77). Minimally invasive cystectomy was associated with lower adjusted 90-day episode spending ($34,369 vs $38,071, P <.001).

CONCLUSION

In patients across diverse institutions in the United States, minimally invasive cystectomy was associated with a shorter length of stay than open cystectomy and reduced 90-day episode spending, but with no significant difference in readmission rate.

The cost of conversion in robotic and laparoscopic colorectal surgery

BACKGROUND

Conversion from minimally invasive to open colorectal surgery remains common and costly. Robotic colorectal surgery is associated with lower rates of conversion than laparoscopy, but institutions and payers remain concerned about equipment and implementation costs. Recognizing that reimbursement reform and bundled payments expand perspectives on cost to include the entire surgical episode, we evaluated the role of minimally invasive conversion in total payments.

METHODS

This is an observational study from a linked data registry including clinical data from the Michigan Surgical Quality Collaborative and payment data from the Michigan Value Collaborative between July 2012 and April 2015. We evaluated colorectal resections initiated with open and minimally invasive approaches, and compared reported risk-adjusted and price-standardized 30-day episode payments and their components.

RESULTS

We identified 1061 open, 1604 laparoscopic, and 275 robotic colorectal resections. Adjusted episode payments were significantly higher for open operations than for minimally invasive procedures completed without conversion ($19,489 vs. $15,518, p < 0.001). The conversion rate was significantly higher with laparoscopic than robotic operations (15.1 vs. 7.6%, p < 0.001). Adjusted episode payments for minimally invasive operations converted to open were significantly higher than for those completed by minimally invasive approaches ($18,098 vs. $15,518, p < 0.001). Payments for operations completed robotically were greater than those completed laparoscopically ($16,949 vs. $15,250, p < 0.001), but the difference was substantially decreased when conversion to open cases was included ($16,939 vs. $15,699, p = 0.041).

CONCLUSION

Episode payments for open colorectal surgery exceed both laparoscopic and robotic minimally invasive options. Conversion to open surgery significantly increases the payments associated with minimally invasive colorectal surgery. Because conversion rates in robotic colorectal operations are half of those in laparoscopy, the excess expenditures attributable to robotics are attenuated by consideration of the cost of conversions.