Surgeon and hospital volume as quality indicators for CABG in Taiwan: examining hazard to mortality and accounting for unobserved heterogeneity

Volume creates value: The volume-outcome relationship in Scandinavian obesity surgery

This study establishes the relationship between surgical volume and cost and quality outcomes, using patient-level clinical data from a national quality registry for bariatric surgery in Sweden. Data include patient characteristics with comorbidities, surgical and follow-up data for patients that underwent gastric bypass or gastric sleeve operations between 2007 and 2016 (52,703 patients in 51 hospitals). The relationships between surgical volume (annual number of bariatric procedures) and several patient-level outcomes were assessed using multilevel, mixed-effect regression models, controlling for patient characteristics and comorbidities. We found that hospitals with higher volumes had lower risk of intraoperative complications as well as complications within 30 days post-surgery (odds ratios per 100 procedures are 0.78 and 0.87, respectively, p<0.01). In addition, higher-volume hospitals had substantially shorter procedure time (17 min per 100 procedures, p<0.01) and length of stay (0.88 incidence-rate ratio per 100 procedures p<0.01). Our results support the claim that increased surgical volume significantly improves quality. Further, the results strongly suggest that increased volume leads to lower cost per surgery, by reducing cost drivers such as procedure time and length of stay.

Maintaining technical proficiency in senior surgical fellows during the COVID-19 pandemic through virtual teaching

Objectives

The novel coronavirus (COVID-19) pandemic resulted in a severe reduction in operative opportunities for trainees. We hypothesized that augmenting independent practice with a bench model of vascular anastomoses using regular videoconferences and individual feedback would provide meaningful benefit in maintenance of technical skills in senior lung transplant surgical fellows.

Methods

A lung transplantation virtual technical skills course was developed. Surgical fellows were provided with a bench model and surgical instruments. Using a virtual communication platform, teaching sessions were held twice weekly, and fellows performed an anastomosis on camera. Video recordings were reviewed and critiqued by attending staff. At the end of the 3-month course, participants were surveyed about their experience. Warm ischaemic time was compared between fellows' five most recent cases before and after the pandemic.

Results

Seven senior surgical fellows participated and provided feedback. Fellows had graduated medical school an average of 14 years prior to fellowship, and spent an average of 5 hours (range 1.3 - 15 hours) of home practice. Five of seven (71%) participants reported improvement in their technical skills and increased confidence in performing a lung transplant. No significant difference in warm ischaemic time in procedures performed by fellows was identified (70.3 minutes pre-pandemic vs. 68.3 minutes post pandemic, p = 0.68).

Conclusions

A program of virtual technical skills teaching, individual video coaching, and independent practice provided benefit in maintaining technical skills in lung transplant surgical fellows during the COVID-19 pandemic, when equivalent operative experience was unavailable. Lessons learned from this exceptional time can be used to create simulation curricula for senior trainees.

Optimal surgeon and hospital volume thresholds to reduce mortality and length of stay for CABG

Objective

We used nationwide population-based data to identify optimal hospital and surgeon volume thresholds and to discover the effects of these volume thresholds on operative mortality and length of stay (LOS) for coronary artery bypass surgery (CABG).

Design

Retrospective cohort study.

Setting

General acute care hospitals throughout Taiwan.

Participants

A total of 12,892 CABG patients admitted between 2011 and 2015 were extracted from Taiwan National Health Insurance claims data.

Main Outcome Measures

Operative mortality and LOS. Restricted cubic splines were applied to discover the optimal hospital and surgeon volume thresholds needed to reduce operative mortality. Generalized estimating equation regression modeling, Cox proportional-hazards modeling and instrumental variables analysis were employed to examine the effects of hospital and surgeon volume thresholds on the operative mortality and LOS.

Results

The volume thresholds for hospitals and surgeons were 55 cases and 5 cases per year, respectively. Patients who underwent CABG from hospitals that did not reach the volume threshold had higher operative mortality than those who received CABG from hospitals that did reach the volume threshold. Patients who underwent CABG with surgeons who did not reach the volume threshold had higher operative mortality and LOS than those who underwent CABG with surgeons who did reach the volume threshold.

Conclusions

This is the first study to identify the optimal hospital and surgeon volume thresholds for reducing operative mortality and LOS. This supports policies regionalizing CABG at high-volume hospitals. Identifying volume thresholds could help patients, providers, and policymakers provide optimal care.

The association between labour epidural case volume and the rate of accidental dural puncture

Accidental dural puncture is a recognised complication of labour epidural placement and can cause a debilitating headache. We examined the association between labour epidural case volume and accidental dural puncture rate in specialist anaesthetists and anaesthesia trainees. We performed a retrospective cohort study of labour epidural and combined spinal-epidural nerve blocks performed between 1 July 2013 and 31 December 2017 at Waitemata District Health Board, Auckland, New Zealand. The mean (SD) annual number of obstetric epidural and combined spinal-epidural procedures for high-case volume specialists was 44.2 (15.0), and for low-case volume specialists was 10.0 (6.8), after accounting for caesarean section combined spinal-epidural procedures. Analysis of 7976 labour epidural and combined spinal-epidural procedure records revealed a total of 92 accidental dural punctures (1.2%). The accidental dural puncture rate (95%CI) in high-case volume specialists was 0.6% (0.4-0.9%) and in low-case volume specialists 2.4% (1.4-3.9%), indicating probable skill decay. The odds of accidental dural puncture were 3.77 times higher for low- compared with high-case volume specialists (95%CI 1.72-8.28, p = 0.001). Amongst trainees, novices had a significantly higher accidental dural puncture complication rate (3.1%) compared with registrars (1.2%), OR (95%CI) 0.39 (0.18-0.84), p = 0.016, or fellows (1.1%), 0.35 (0.16-0.76), p = 0.008. Accidental dural puncture complication rates decreased once trainees progressed past the 'novice' training stage.

Do informed consumers in Taiwan favour larger hospitals? A 10-year population-based study on differences in the selection of healthcare providers among medical professionals, their relatives and the general population

OBJECTIVES

Exploring whether medical professionals, who are considered to be 'informed consumers' in the healthcare system, favour large providers for elective treatments. In this study, we compare the inclination of medical professionals and their relatives undergoing treatment for childbirth and cataract surgery at medical centres, against those of the general population.

DESIGN

Retrospective study using a population-based matched cohort data.

PARTICIPANTS

Patients who underwent childbirth or cataract surgery between 1 January 2004 and 31 December 2013.

PRIMARY AND SECONDARY OUTCOMES MEASURES

We used multiple logistic regression to compare the ORs of medical professionals and their relatives undergoing treatment at medical centres, against those of the general population. We also compared the rate of 14-day re-admission (childbirth) and 14-day reoperation (cataract surgery) after discharge between these groups.

RESULTS

Multivariate analysis showed that physicians were more likely than patients with no familial connection to the medical profession to undergo childbirth at medical centres (OR 5.26, 95% CI 3.96 to 6.97, p<0.001), followed by physicians' relatives (OR 2.68, 95% CI 2.20 to 3.25, p<0.001). Similarly, physicians (OR 1.63, 95% CI 1.21 to 2.19, p<0.01) and their relatives (OR 1.43, 95% CI 1.13 to 1.81, p<0.01) were also more likely to undergo cataract surgery at medical centres. Physicians also tended to select healthcare providers who were at the same level or above the institution at which they worked. We observed no significant difference in 14-day re-admission rates after childbirth and no significant difference in 14-day reoperation rates after cataract surgery across patient groups.

CONCLUSIONS

Medical professionals and their relatives are more likely than the general population to opt for service at medical centres. Understanding the reasons that medical professionals and general populations both have a preferential bias for larger medical institutions could help improve the efficiency of healthcare delivery.

Lessons learned and learning curve of fenestrated and branched endografts

Fenestrated and branched endovascular repair (F-BEVAR) has been increasingly used to treat patients with complex aortic aneurysms involving the renal-mesenteric arteries. As with any new procedure, there is a learning curve associated with mastering the technique. However, proficiency with deployment is only one aspect of the learning process, and ultimately, this curve is defined not by one quality parameter, but by patient selection, the performance of the entire team, the surgeon's ability to adapt to unexpected events, and the durability of the repair. This article reviews the importance of novel training paradigms, learning curve, and factors affecting outcomes of complex endovascular aneurysm repair.

Risk Factors for In-Hospital Mortality in Heart Failure Patients: Does Rurality, Payer or Admission Source Matter?

PURPOSE

Considering the high prevalence of heart failure and the economic burden of the disease, factors that influence in-hospital mortality are of importance in improving outcomes of care for this patient population. The purpose of this study was to examine the determinants of in-hospital mortality for adult heart failure patients.

METHODS

The study design is a retrospective observational study design using the 2010 Nebraska Hospital Discharge data set including 4,319 hospitalizations for 3,521 heart failure patients admitted to 79 hospitals in Nebraska. Hierarchical logistic regression models including patient- and hospital-specific random intercepts were analyzed. Covariates included in the analysis were patient age in years, gender, comorbidity status, length of stay, primary payer, type and source of admission, transfers, and rurality of county of residence.

RESULTS

Overall, 3.5% of heart failure patients died during their hospital stay. In logistic regression analysis that adjusted for age, sex, and comorbidities, the odds of dying in hospital for heart failure patients increased with age (OR = 1.03, 95% CI: 1.01-1.04), co-morbidity (OR = 1.15; 95% CI: 1.05-1.25) and length of stay (OR = 1.03, 95% CI: 1.01-1.05). The patient's gender, payer source, rurality of county of residence, source, and type of admission were not risk factors for in-hospital death.

CONCLUSION

Increasing age, comorbidity and length of stay were risk factors for in-hospital death for heart failure. An understanding of the risk factors for in-hospital death is critical to improving outcomes of care for heart failure patients.

Preoperative factors affecting cost and length of stay for isolated off-pump coronary artery bypass grafting: hierarchical linear model analysis

OBJECTIVE

To determine the effect of preoperative patient and hospital factors on resource use, cost and length of stay (LOS) among patients undergoing off-pump coronary artery bypass grafting (OPCAB).

DESIGN

Observational retrospective study.

SETTINGS

Data from the Japanese Administrative Database.

PARTICIPANTS

Patients who underwent isolated, elective OPCAB between April 2011 and March 2012.

PRIMARY OUTCOME MEASURES

The primary outcomes of this study were inpatient cost and LOS associated with OPCAB. A two-level hierarchical linear model was used to examine the effects of patient and hospital characteristics on inpatient costs and LOS. The independent variables were patient and hospital factors.

RESULTS

We identified 2491 patients who underwent OPCAB at 268 hospitals. The mean cost of OPCAB was $40 665 ±7774, and the mean LOS was 23.4±8.2 days. The study found that select patient factors and certain comorbidities were associated with a high cost and long LOS. A high hospital OPCAB volume was associated with a low cost (-6.6%; p=0.024) as well as a short LOS (-17.6%, p<0.001).

CONCLUSIONS

The hospital OPCAB volume is associated with efficient resource use. The findings of the present study indicate the need to focus on hospital elective OPCAB volume in Japan in order to improve cost and LOS.

Does Categorization Method Matter in Exploring Volume-Outcome Relation? A Multiple Categorization Methods Comparison in Coronary Artery Bypass Graft Surgery Surgical Site Infection

BACKGROUND

Volume-infection relation studies have been published for high-risk surgical procedures, although the conclusions remain controversial. Inconsistent results may be caused by inconsistent categorization methods, the definitions of service volume, and different statistical approaches. The purpose of this study was to examine whether a relation exists between provider volume and coronary artery bypass graft (CABG) surgical site infection (SSI) using different categorization methods.

METHODS

A population-based cross-sectional multi-level study was conducted. A total of 10,405 patients who received CABG surgery between 2006 and 2008 in Taiwan were recruited. The outcome of interest was surgical site infection for CABG surgery. The associations among several patient, surgeon, and hospital characteristics was examined. The definition of surgeons' and hospitals' service volume was the cumulative CABG service volumes in the previous year for each CABG operation and categorized by three types of approaches: Continuous, quartile, and k-means clustering.

RESULTS

The results of multi-level mixed effects modeling showed that hospital volume had no association with SSI. Although the relation between surgeon volume and surgical site infection was negative, it was inconsistent among the different categorization methods.

CONCLUSIONS

Categorization of service volume is an important issue in volume-infection study. The findings of the current study suggest that different categorization methods might influence the relation between volume and SSI. The selection of an optimal cutoff point should be taken into account for future research.

Do low-income coronary artery bypass surgery patients have equal opportunity to access excellent quality of care and enjoy good outcome in Taiwan?

BACKGROUND

Equity is an important issue in the healthcare research field. Many studies have focused on the relationship between patient characteristics and outcomes of care. These studies, however, have seldom examined whether patients' characteristics affected their access to quality healthcare, which further affected the care outcome. The purposes of this study were to determine whether low-income coronary artery bypass surgery (CABG) patients receive healthcare services with poorer quality, and if such differences in treatment result in different outcomes.

METHODS

A retrospective multilevel study design was conducted using claims data from Taiwan's universal health insurance scheme for 2005-2008. Patients who underwent their CABG surgery between 2006 and 2008 were included in this study. CABG patients who were under 18 years of age or had unknown gender or insured classifications were excluded. Hospital and surgeon's performance indicators in the previous one year were used to evaluate the level of quality via k-means clustering algorithm. Baron and Kenny's procedures for mediation effect were conducted to explore the relationship among patient's income, quality of CABG care, and inpatient mortality.

RESULTS

A total of 10,320 patients were included in the study. The results showed that 5.65% of the low-income patients received excellent quality of care, which was lower than that of patients not in the low-income group (5.65% vs.11.48%). The mortality rate of low-income patients (12.10%) was also higher than patients not in the low-income group (5.25%). Also, the mortality of patients who received excellent care was half as low as patients receiving non-excellent care (2.63% vs. 5.68%). Finally, after the procedure of mediation effect testing, the results showed that the relationship between patient income level and CABG mortality was partially mediated by patterns of quality of care.

CONCLUSIONS

The results of the current study implied that worse outcome in low-income CABG patients might be associated with poorer quality of received services. Health authorities should pay attention to this issue, and propose appropriate solutions.

The nature of surgeon human capital depreciation

To test how practice interruptions affect worker productivity, we estimate how temporal breaks affect surgeons' performance of coronary artery bypass grafting (CABG). Examining 188 surgeons who performed 56,315 CABG surgeries in Pennsylvania between 2006 and 2010, we find that a surgeon's additional day away from the operating room raised patients' inpatient mortality by up to 0.067 percentage points (2.4% relative effect) but reduced total hospitalization costs by up to 0.59 percentage points. Among emergent patients treated by high-volume providers, where temporal distance is most plausibly exogenous, an additional day away raised mortality risk by 0.398 percentage points (11.4% relative effect) but reduced cost by up to 1.4 percentage points. This is consistent with the hypothesis that as temporal distance increases, surgeons are less likely to recognize and address life-threatening complications. Our estimates imply additional intraprocedural treatment intensity has a cost per life-year preserved of $7871-18,500, well within conventional cost-effectiveness cutoffs.

Outcomes of cardiac surgery: associations with physician characteristics, institutional characteristics, and transfers of care

BACKGROUND

Although there are several studies of the human and system factors that influence the outcomes of cardiac surgery, it remains difficult to draw conclusions because many do not simultaneously adjust for the characteristics of patients, physicians, and institutions. The current study explores the associations between these factors and inhospital mortality, with a particular focus on whether patients had the same operating and attending physician.

METHOD AND RESULTS

This is a retrospective observational study of 114,751 hospitalizations from 2003 to 2009 in Pennsylvania that included a coronary artery bypass graft, valve surgery, or both. The study included 70 teaching and nonteaching hospitals, 289 operating physicians who were also the attending physicians for 75% of the hospitalizations, and 2654 attending physicians for the remaining hospitalizations. After adjustment, there was a 38.4% decrease (95% CI, 20.3%-56.5%) in mortality when the operating and attending physician were the same. For the operator, each procedure performed was associated with a 0.05% (95% CI, 0.04%-0.06%) decrease in mortality and each year since medical school was associated with a 0.9% (95% CI, 0.02%-1.8%) increase in mortality. For the attending, each year since medical school was associated with a 0.67% (95% CI, 0.01%-1.4%) decrease in patient mortality.

CONCLUSIONS

The findings indicated that an increase in the log odds of mortality was associated with the transfer of care between an attending and operating physician. Better patient outcomes were associated with an operator with higher volume who was closer to medical school graduation and an attending physician with more clinical experience.

The effect of surgeon volume on mortality for off-pump coronary artery bypass grafting

OBJECTIVE

Recent trials comparing on-pump (CABG) with off-pump coronary artery bypass grafting (OPCAB) have been criticized by those who believe that surgeon inexperience may explain the apparent worse outcomes for OPCAB. However, the true effect of surgeon volume on outcomes after OPCAB remains unknown. The purpose of this study was to examine the effect of surgeon volume on risk-adjusted mortality after OPCAB.

METHODS

From 2003 to 2007, 709,483 patients underwent coronary artery bypass grafting operations (CABG = 439,253; OPCAB = 270,230) within the Nationwide Inpatient Sample database. Hierarchic generalized linear regression modeling with spline functions for annual individual operating surgeon volume was used to assess the relationship between annual surgeon volume and inpatient mortality, adjusted for comorbid disease and other potential confounders.

RESULTS

OPCAB was performed in 38.1% of coronary artery bypass grafting operations. The average age for those undergoing OPCAB was 66.1 ± 11.1 years, and female patients accounted for 29.3% of operations with 1-vessel (20.4%), 2-vessel (36.6%), 3-vessel (20.5%), or 4 vessels or more (13.6%). Median surgeon volume for OPCAB was 105 (56-156) operations per year. A highly significant nonlinear relationship between surgeon volume and risk-adjusted mortality was observed for OPCAB operations (P < .01). Specifically, an estimated 5% decrease in the absolute probability of death occurred after OPCAB performed by the surgeons with the highest volume, which is greater than the 3% estimated decrease for conventional CABG. Of note, the effect of surgeon volume on mortality was significantly less than other risk factors, such as the presence of heart failure, renal failure, type of bypass conduit, and gender.

CONCLUSIONS

A significant surgeon volume-outcome relationship exists for mortality after OPCAB with a threshold of more than 50 operations per year. However, the contribution of surgeon volume to the probability of death is incrementally small compared with other patient and operative characteristics. This demonstrates that outcomes after OPCAB are more dependent on patient risk factors than on surgeon volume.