Relationship of hospital size, case volume, and cost for coronary artery bypass surgery: analysis of 12,774 patients operated on in Massachusetts during fiscal years 1995 and 1996

Institutional case volume and mortality after aortic and mitral valve replacement: a nationwide study in two Korean cohorts

Background

There are only a handful of published studies regarding the volume-outcome relationship in heart valve surgery. We evaluated the association between institutional case volume and mortality after aortic valve replacement (AVR) and mitral valve replacement (MVR).

Methods

Two separate cohorts of all adults who underwent AVR or MVR, respectively, between 2009 and 2016 were analyzed using a Korean healthcare insurance database. Hospitals performing AVRs were divided into three groups according to the average annual case volume: the low- (< 20 cases/year), medium- (20–70 cases/year), and high-volume centers (> 70 cases/year). Hospitals performing MVRs were also grouped as the low- (< 15 cases/year), medium- (15–40 cases/year), or high-volume centers (> 40 cases/year). In-hospital mortality after AVR or MVR were compared among the groups.

Results

In total, 7875 AVR and 5084 MVR cases were analyzed. In-hospital mortality after AVR was 8.3% (192/2318), 4.0% (84/2102), and 2.6% (90/3455) in the low-, medium-, and high-volume centers, respectively. The adjusted risk was higher in the low- (OR 2.31, 95% CI 1.73–3.09) and medium-volume centers (OR 1.53, 95% CI 1.09–2.15) compared to the high-volume centers. In-hospital mortality after MVR was 9.3% (155/1663), 6.3% (94/1501), and 2.9% (56/1920) in the low-, medium-, and high-volume centers, respectively. Compared to the high-volume centers, the medium- (OR 1.97, 95% CI 1.35–2.88) and low-volume centers (OR 2.29, 95% CI 1.60–3.27) showed higher adjusted risk of in-hospital mortality.

Conclusions

Lower case volume is associated with increased in-hospital mortality after AVR and MVR. The results warrant a comprehensive discussion regarding regionalization/centralization of cardiac valve replacements to optimize patient outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-01945-0.

Impact of Mitral Valve Repair Case Volume on Postoperative Mortality - A Nationwide Korean Cohort Study

BACKGROUND

Although mitral valve repair is recommended over replacement due to better outcomes, repair rates vary significantly among centers. This study examined the effect of institutional mitral valve repair volume on postoperative mortality.Methods and Results:All cases of adult mitral valve repair performed in Korea between 2009 and 2016 were analyzed. The association between case volume and 1-year mortality was analyzed after categorizing centers according to the number of mitral valve repairs performed as low-, medium-, or high-volume centers (<20, 20-40, and >40 cases/year, respectively). The effect of case volume on cumulative all-cause mortality was also assessed. In all, 6,041 mitral valve repairs were performed in 86 centers. The 1-year mortality in low-, medium-, and high-volume centers was 10.1%, 8.7%, and 4.7%, respectively. Low- and medium-volume centers had increased risk of 1-year mortality compared with high-volume centers, with odds ratios of 2.80 (95% confidence interval [CI] 2.15-3.64; P<0.001) and 2.66 (95% CI 1.94-3.64; P<0.001), respectively. The risk of cumulative all-cause mortality was also worse in low- and medium-volume centers, with hazard ratios of 1.96 (95% CI 1.68-2.29; P<0.001) and 1.77 (95% CI 1.47-2.12; P<0.001), respectively.

CONCLUSIONS

Lower institutional case volume was associated with higher mortality after mitral valve repair. A minimum volume standard may be required for hospitals performing mitral valve repair to guarantee adequate outcome.

Incidence and impact of adverse effects to antibiotics in hospitalized adults with pneumonia

BACKGROUND

This study sought to define the incidence, economic impact, and nature of adverse drug effects (ADEs) related to antibiotics in pneumonia hospitalizations in the US.

METHODS

Adult pneumonia hospitalizations were tabulated in statewide (New York) and national databases, respectively, from 2000 through 2005. The incidences of antibiotic related ADEs were determined by identifying antibiotic specific e-codes (external cause of injury codes). The modeled effect of the presence of antibiotic ADEs on length of stay (LOS) and total charges were also calculated. ADEs due to specific antibiotic classes, and the presence of certain cutaneous allergic and gastro-intestinal manifestations commonly attributable to ADEs, were tabulated.

RESULTS

ADEs related to antibiotics were reported in a small but consistent proportion (0.45-0.6%) of pneumonia hospitalizations in both cohorts. The most common identifiable antibiotics class associated with ADEs was the cephalosporins followed by penicillins and quinolones. Over 60% of the ADEs were associated with reported dermal/allergic and gastro-intestinal manifestations. Multivariate analysis adjusting for co-morbid conditions and demographic factors showed that the presence of an antibiotic adverse drug effect was a significant independent predictor of greater LOS and higher total hospital charges.

CONCLUSIONS

ADEs related to antibiotics can be identified by analyzing administrative hospitalization databases. For pneumonia, a common hospitalization diagnosis, there is a defined calculable impact and incidence of antibiotic associated adverse effects. This should be considered in planning hospitalization resource allocation and in developing equitable hospitalization reimbursements. Identifying the nature of antibiotic associated adverse effects may facilitate the development of strategies for reducing these adverse effects.

Does physicians' case volume impact inpatient care costs for pneumonia cases?

BACKGROUND

Increasing physician case volumes are documented to reduce costs and improve outcomes for many surgical procedures but not for medical conditions such as pneumonia that consume significant health care resources.

OBJECTIVE

This study explored the association between physicians' inpatient pneumonia case volume and cost per discharge.

DESIGN

The design was a retrospective, population-based, cross-sectional study, using National Health Insurance administrative claims data.

SETTING

The setting was Taiwan.

PARTICIPANTS

The participants were a universal sample of 270,002 adult, acute pneumonia hospitalizations, during 2002-2004, excluding transferred cases and readmissions.

MEASUREMENTS

Hierarchical linear regression modeling was used to examine the association of physician's volume (three volume groups, designed to classify patients into approximately equal sized groups) with cost, adjusting for hospital random effects, case severity, physician demographics and specialty, hospital characteristics, and geographic location.

RESULTS

Mean cost was NT$2,255 (US$1 = NT$33 in 2004) for low-volume physicians (< or =100 cases) and NT$1,707 for high-volume physicians (> or =316 cases). The adjusted patient costs for low-volume physicians were higher (US$264 and US$235 than high- and medium-volume physicians, respectively; both P < .001), with no difference between high- and medium-volume physicians. High-volume physicians had lower in-hospital mortality and 14-day readmission rates than low-volume physicians.

CONCLUSIONS

Data support an inverse volume-cost relationship for pneumonia care. Decision processes and clinical care of high-volume physicians versus low-volume physicians should be studied to develop effective care algorithms to improve pneumonia outcomes and reduce costs.

Estimating cost savings from regionalizing cardiac procedures using hospital discharge data

BACKGROUND

We examined whether higher procedure volumes for coronary artery bypass graft (CABG) surgery or percutaneous coronary interventions (PCI) were associated with lower costs per patient, and if so, estimated the financial savings from regionalizing cardiac procedures.

METHODS

Cost regressions with hospital-specific dummy variables measured within-hospital cost reductions associated with increasing hospital volume. We used the regression estimates to predict the change in total costs that would result from moving patients in low-volume hospitals to higher volume facilities.

RESULTS

A 10% increase in PCI procedure volume lowered costs per patient by 0.7%. For the average hospital performing CABG in 2000, a 10% increase in volume was associated with a 2.8% reduction in average costs. Despite these lower costs, the predicted savings from regionalizing all PCI procedures in the sample from lower to high-volume hospitals amounted to only 1.1% of the entire costs of performing PCI procedures for the sample in 2000. Similarly, the cost savings for CABG were estimated to be only 3.5%.

CONCLUSION

Higher volumes were associated with lower costs per procedure. However, the total potential savings from regionalizing cardiac procedures is relatively minor, and may not justify the risks of reducing access to needed services.

Hospital volume, length of stay, and readmission rates in high-risk surgery

OBJECTIVE

Aimed at reducing surgical deaths, several recent initiatives have attempted to establish volume-based referral strategies in high-risk surgery. Although payers are leading the most visible of these efforts, it is unknown whether volume standards will also reduce resource use.

METHODS

We studied postoperative length of stay and 30-day readmission rate after 14 cardiovascular and cancer procedures using the 1994-1999 national Medicare database (total n = 2.5 million). We used regression techniques to examine the relationship between length of stay, 30-day readmission, and hospital volume, adjusting for age, gender, race, comorbidity score, admission acuity, and mean social security income.

RESULTS

Mean postoperative length of stay ranged from 3.4 days (carotid endarterectomy) to 19.6 days (esophagectomy). There was no consistent relationship between volume and mean length of stay; it significantly increased across volume strata for 7 of the 14 procedures and significantly decreased across volume strata for the other 7. Mean length of stay at very-low-volume and very-high-volume hospitals differed by more than 1 day for 6 procedures. Of these, the mean length of stay was shorter in high-volume hospitals for 3 procedures (pancreatic resection, esophagectomy, cystectomy), but longer for other procedures (aortic and mitral valve replacement, gastrectomy). The 30-day readmission rate also varied widely by procedure, ranging from 9.9% (nephrectomy) to 22.2% (mitral valve replacement). However, volume was not related to 30-day readmission rate with any procedure.

CONCLUSION

Although hospital volume may be an important predictor of operative mortality, it is not associated with resource use as reflected by length of stay or readmission rates.