Case-mix adjustment to compare nationwide hospital performances after resection of colorectal liver metastases

Nationwide clinical practice variation for reconstructive surgery following oral cavity cancer from the Dutch Head and Neck Audit: are we all doing the same?

Quality registries provide real-world data that can drive quality improvement, which often starts with reducing inter-hospital variation. We explored outcomes and the extent of nationwide inter-hospital variation for patients undergoing reconstructive surgery after oral cavity cancer (OCC) using the Dutch Head and Neck Audit (DHNA). Within the DHNA, we selected all OCC patients who underwent curative reconstructive surgery between 2018 and 2022. Patient, tumour, and treatment characteristics were compared, including reconstruction strategies (skin grafting, local transposition, and pedicled and free flaps). Of those treated with free flap reconstruction, postoperative complications were scored according to the Clavien-Dindo (CD) classification and labelled minor (CD 1-2) or major (CD ≥3). A total of 1383 patients were included in the analysis. Especially in the case of patients with stage I tumours (10.1%) there was a wide variation in reconstructive surgery between centres, with a preference for local transposition (42.6%). Free flaps (n = 974) were used most often in patients with a more extensive tumour load (65.4-89.2%), with the radial forearm flap the preferred technique (54.7%, range range 37.1-80.8%). Thirty-four per cent of patients treated with a free flap had postoperative complications, with 38 cases of total flap loss (overall 3.9% complications). Strategies and percentages varied widely across centres, showing high inter-hospital variation in applied techniques and outcomes, and the need for national data improvement. Level of evidence: II.

Surgical Complications for Oral Cavity Cancer: Evaluating Hospital Performance

OBJECTIVE

Complications of oral cavity cancer (OCC) surgery have an impact on the quality of life. Therefore, evaluating hospital performance on complication rates can help identify best practices for improving the quality of OCC care. As patient and tumor characteristics also impact hospital results, case-mix adjustment should be considered to provide a valid hospital comparison. This study investigated hospital variation in the quality indicator "a complicated postoperative course" after OCC surgery.

METHODS

This population-based cohort included all first primary OCC patients diagnosed between 2018 and 2021 who were surgically treated with curative intent. A complicated postoperative course was defined as 30-day mortality, unplanned readmission, surgical complications requiring reintervention or prolonged hospital stay, or fistula formation. Hospital performance was analyzed using funnel plots with case-mix correction.

RESULTS

A total of 2,266 OCC patients could be included. The distribution of case-mix variables varied significantly between hospital populations. Nationally, a complicated postoperative course occurred in 13.9% and uncorrected hospital rates ranged from 2.7% to 31.1%. A WHO performance score ≥2, cT3-T4 tumors, and floor-of-mouth tumors were associated with an increased risk of a complicated postoperative course, and non-squamous cell carcinoma with a decreased risk. Significant outliers remained after case-mix correction for patient, tumor, and treatment characteristics.

CONCLUSION

Complications after OCC surgery are prevalent, especially regarding extensive tumors and surgery. To identify best practices in OCC surgery, hospital performance on a complicated postoperative course should be adjusted for case-mix and treatment variables. Providing feedback on hospital performance for complications can instigate improvement plans for better outcomes.

LEVEL OF EVIDENCE

3 Laryngoscope, 2025.

High-impact complications after breast cancer surgery in the Dutch national quality registry: evaluating case-mix adjustment for hospital comparisons

BACKGROUND

Comparison of quality indicators can improve quality of care. However, case-mix adjustment is deemed essential. The aim of this study was to develop and validate case-mix adjustment models and to evaluate the effect of case-mix adjustment for the quality indicators related to complications after breast cancer surgery.

METHODS

Multivariable logistic regression with backward selection (P < 0.1) was used to develop case-mix models in patients undergoing breast cancer surgery (all types, breast-conserving surgery, mastectomy with or without immediate reconstruction) in the Netherlands (NABON Breast Cancer Audit). High-impact complications were defined as Clavien Dindo grade ≥3. Model performance was assessed using the area under the receiver operating characteristic curve (AUC), corrected for optimism with bootstrap validation. Observed-to-expected plots were used to visualize the difference between unadjusted and case-mix adjusted hospital performance (hospital shifts).

RESULTS

In total 32 084 patients from 72 hospitals treated in 2021-2022 were included. A between-hospital variation in complication rates was observed for all surgeries (interquartile range 2.4-6.0%), breast-conserving surgery (interquartile range 1.4-3.4%), and mastectomy with (interquartile range 9.4-9.1%) and without reconstruction (interquartile range 3.3-9.7%). Of the considered variables, body mass index, smoking, multifocality and neoadjuvant therapy were weakly associated with complications. However, surgery type was strongly related to complications (AUC 0.70), resulting in noticeable hospital shifts in the quality indicator scores comprising all surgeries. After stratification for surgery type, no evident hospital shifts were observed after case-mix correction.

CONCLUSION

For valid comparison of complication rates after breast cancer surgery between hospitals, stratification by surgery type is crucial. Subsequently, the evaluated patient and tumour characteristics have a negligible effect on the hospital variation.

Optimizing Hospital Performance Evaluation in Total Weight Loss Outcomes After Bariatric Surgery: A Retrospective Analysis to Guide Further Improvement in Dutch Hospitals

INTRODUCTION

Bariatric surgery aims for optimal patient outcomes, often evaluated through the percentage total weight loss (%TWL). Quality registries employ funnel plots for outcome comparisons between hospitals. However, funnel plots are traditionally used for dichotomous outcomes, requiring %TWL to be dichotomized, potentially limiting feedback quality. This study evaluates whether a funnel plot around the median %TWL has better discriminatory performance than binary funnel plots for achieving at least 20% and 25% TWL.

METHODS

All hospitals performing bariatric surgery were included from the Dutch Audit for Treatment of Obesity. A funnel plot around the median was constructed using 5-year %TWL data. Hospitals positioned above the 95% control limit were colored green and those below red. The same hospitals were plotted in the binary funnel plots for 20% and 25% TWL and colored according to their performance in the funnel plot around the median. We explored the hospital's procedural mix in relation to %TWL performance as possible explanatory factors.

RESULTS

The median-based funnel plot identified four underperforming and four outperforming hospitals, while only one underperforming and no outperforming hospitals were found with the binary funnel plot for 20% TWL. The 25% TWL binary funnel plot identified two underperforming and three outperforming hospitals. The proportion of sleeve gastrectomies performed per hospital may explain part of these results as it was negatively associated with median %TWL (β =  - 0.09, 95% confidence interval [- 0.13 to - 0.04]).

CONCLUSION

The funnel plot around the median discriminated better between hospitals with significantly worse and better performance than funnel plots for dichotomized %TWL outcomes.

Hospital variation and outcomes after repeat hepatic resection for colorectal liver metastases: a nationwide cohort study

BACKGROUND

Approximately 70% of patients with colorectal liver metastases (CRLM) experiences intrahepatic recurrence after initial liver resection. This study assessed outcomes and hospital variation in repeat liver resections (R-LR).

METHODS

This population-based study included all patients who underwent liver resection for CRLM between 2014 and 2022 in the Netherlands. Overall survival (OS) was collected for patients operated on between 2014 and 2018 by linkage to the insurance database.

RESULTS

Data of 7479 liver resections (1391 (18.6%) repeat and 6088 (81.4%) primary) were analysed. Major morbidity and mortality were not different. Factors associated with major morbidity included ASA 3+, major liver resection, extrahepatic disease, and open surgery. Five-year OS after repeat versus primary liver resection was 42.3% versus 44.8%, P = 0.37. Factors associated with worse OS included largest CRLM >5 cm (aHR 1.58, 95% CI: 1.07-2.34, P = 0.023), >3 CRLM (aHR 1.33, 95% CI: 1.00-1.75, P = 0.046), extrahepatic disease (aHR 1.60, 95% CI: 1.25-2.04, P = 0.001), positive tumour margins (aHR 1.42, 95% CI: 1.09-1.85, P = 0.009). Significant hospital variation in performance of R-LR was observed, median 18.9% (8.2% to 33.3%).

CONCLUSION

Significant hospital variation was observed in performance of R-LR in the Netherlands reflecting different treatment decisions upon recurrence. On a population-based level R-LR leads to satisfactory survival.

Outcomes of liver surgery: A decade of mandatory nationwide auditing in the Netherlands

BACKGROUND

In 2013, the nationwide Dutch Hepato Biliary Audit (DHBA) was initiated. The aim of this study was to evaluate changes in indications for and outcomes of liver surgery in the last decade.

METHODS

This nationwide study included all patients who underwent liver surgery for four indications, including colorectal liver metastases (CRLM), hepatocellular carcinoma (HCC), and intrahepatic- and perihilar cholangiocarcinoma (iCCA - pCCA) between 2014 and 2022. Trends in postoperative outcomes were evaluated separately for each indication using multilevel multivariable logistic regression analyses.

RESULTS

This study included 8057 procedures for CRLM, 838 for HCC, 290 for iCCA, and 300 for pCCA. Over time, these patients had higher risk profiles (more ASA-III patients and more comorbidities). Adjusted mortality decreased over time for CRLM, HCC and iCCA, respectively aOR 0.83, 95%CI 0.75-0.92, P < 0.001; aOR 0.86, 95%CI 0.75-0.99, P = 0.045; aOR 0.40, 95%CI 0.20-0.73, P < 0.001. Failure to rescue (FTR) also decreased for these groups, respectively aOR 0.84, 95%CI 0.76-0.93, P = 0.001; aOR 0.81, 95%CI 0.68-0.97, P = 0.024; aOR 0.29, 95%CI 0.08-0.84, P = 0.021). For iCCA severe complications (aOR 0.65 95%CI 0.43-0.99, P = 0.043) also decreased. No significant outcome differences were observed in pCCA. The number of centres performing liver resections decreased from 26 to 22 between 2014 and 2022, while median annual volumes did not change (40-49, P = 0.66).

CONCLUSION

Over time, postoperative mortality and FTR decreased after liver surgery, despite treating higher-risk patients. The DHBA continues its focus on providing feedback and benchmark results to further enhance outcomes.

Developing quality indicators for cancer hospitals in China: a national modified Delphi process

OBJECTIVE

Although demand and supply of cancer care have been rapidly increasing in recent decades, there is a lack of systemic quality measurement for cancer hospitals in China. This study aimed to develop a set of core indicators for measuring quality of care for cancer hospitals in China.

DESIGN

The development of quality indicators was based on a literature review and a two-round modified Delphi survey. The theoretical framework and initial indicators were identified through the comprehensive literature review, and the selection of quality indicators relied on experts' consensus on the importance and feasibility of indicators by the modified Delphi process. In addition, indicator weight was identified using the analytical hierarchical process method and percentage weight method.

SETTING AND PARTICIPANTS

A panel of leading experts including oncologists, cancer care nurses, quality management experts from various regions of China were invited to participate in the two-round modified Delphi process from October to December 2020. A total of 25 experts completed the two-round modified Delphi process.

RESULTS

The experts reached consensus on a set of 47 indicators, comprising 17 structure indicators, 19 process indicators and 11 outcome indicators. Experts gave much higher weight to outcome indicators (accounting for 53.96% relative weight) than to structure (16.34%) and process (29.70%) indicators. In addition, experts also showed concerns and gave suggestions on data availability of specific outcome indicators.

CONCLUSIONS

Drawing on the comprehensive literature review and the modified Delphi process, this study developed a core set of quality indicators that can be used to evaluate quality performance of cancer hospitals. This is helpful in supporting quality cancer care in China and will provide new insights into the systemic measurement of cancer care internationally.

The Impact of a Liver Transplant Program on the Outcomes of Hepatocellular Carcinoma

OBJECTIVE

We sought to evaluate the impact of liver transplantation (LT) programs on the prognosis of hepatocellular carcinoma (HCC) patients who underwent liver resection (LR) and noncurative intent treatment.

BACKGROUND

LT programs have an array of resources and services that would positively affect the prognosis of patients with HCC.

METHODS

Patients who underwent LT, LR, radiotherapy (RT), or chemotherapy (CTx) for HCC between 2004 and 2018 were included in the National Cancer Database. Institutions with LT programs were defined as those that performed 1 or more LT for at least 5 years. Centers were stratified by hospital volume. The impact of LT programs was assessed after propensity score matching to achieve covariate balance.

RESULTS

A total of 71,735 patients were identified, of which 7997 received LT (11.1%), 12,683 LR (17.7%), 15,675 RT (21.9%), and 35,380 CTx (49.3%). Among a total of 1267 distinct institutions, 94 (7.4%) were categorized as LT programs. Designation as an LT program was also associated with a high volume of LR and noncurative intent treatment (both P <0.001). After propensity score matching, LT programs were associated with better survival among LR and noncurative intent treatment patients. Although hospital volume was also associated with improved prognosis, LT programs were associated with additional survival benefits in noncurative intent treatment. On the other hand, no such benefit was noted in patients who underwent LR.

CONCLUSIONS

The presence of an LT program was associated with a higher volume of LR and noncurative intent treatment. Furthermore, designation as an LT program had a "halo effect" on the prognosis of patients undergoing RT/CTx that went beyond the procedure-volume effect.

Textbook outcome as a composite outcome measure to compare hospital performances regarding cytoreductive surgery for ovarian cancer: A nationwide population-based study

OBJECTIVE

Textbook outcome (TO) is a composite outcome measure used in surgical oncology to compare hospital outcomes using multiple quality indicators. This study aimed to develop TO as an outcome measure to assess healthcare quality for patients undergoing cytoreductive surgery (CRS) for advanced-stage ovarian cancer.

METHODS

This population-based study included all CRS for FIGO IIIC-IVB primary ovarian cancer registered in the Netherlands between 2017 and 2020. The primary outcome was TO, defined as a complete CRS, combined with the absence of 30-day mortality, severe complications, and prolonged length of admission (≥ten days). Delayed start of adjuvant chemotherapy (≥six weeks) was not included in TO because of missing data. Logistic regressions were used to assess the association of case-mix factors with TO. Hospital variation was displayed using funnel plots.

RESULTS

A total of 1909 CRS were included, of which 1434 were interval CRS and 475 were primary CRS. TO was achieved in 54% of the interval CRS cohort and 47% of the primary CRS cohort. Macroscopic residual disease after CRS was the most important factor for not achieving TO. Age ≥ 70 was associated with lower TO rates in multivariable logistic regressions. TO rates ranged from 40% to 69% between hospitals in the interval CRS cohort and 22% to 100% in the primary CRS cohort. In both analyses, one hospital had significantly lower TO rates (different hospitals). Case-mix adjustment significantly affected TO rates in the primary CRS analysis.

CONCLUSIONS

TO is a suitable composite outcome measure to detect hospital variation in healthcare quality for patients with advanced-stage ovarian cancer undergoing CRS. Case-mix adjustment improves the accuracy of the hospital comparison.

Pulmonary metastasectomy and repeat metastasectomy for colorectal pulmonary metastases: outcomes from the Dutch Lung Cancer Audit for Surgery

BACKGROUND

Surgical resection of recurrent pulmonary metastases in patients with colorectal cancer is an established treatment option; however, the evidence for repeat resection is limited. The aim of this study was to analyse long-term outcomes from the Dutch Lung Cancer Audit for Surgery.

METHODS

Data from the mandatory Dutch Lung Cancer Audit for Surgery were used to analyse all patients after metastasectomy or repeat metastasectomy for colorectal pulmonary metastases from January 2012 to December 2019 in the Netherlands. Kaplan-Meier survival analysis was performed to determine the difference in survival. Multivariable Cox regression analyses were performed to identify predictors of survival.

RESULTS

A total of 1237 patients met the inclusion criteria, of which 127 patients underwent repeat metastasectomy. Five-year overall survival was 53 per cent after pulmonary metastasectomy for colorectal pulmonary metastases and 52 per cent after repeat metastasectomy (P = 0.852). The median follow-up was 42 (range 0-285) months. More patients experienced postoperative complications after repeat metastasectomy compared with the first metastasectomy (18.1 per cent versus 11.6 per cent respectively; P = 0.033). Eastern Cooperative Oncology Group performance status greater than or equal to 1 (HR 1.33, 95 per cent c.i. 1.08 to 1.65; P = 0.008), multiple metastases (HR 1.30, 95 per cent c.i. 1.01 to 1.67; P = 0.038), and bilateral metastases (HR 1.50, 95 per cent c.i. 1.01 to 2.22; P = 0.045) were prognostic factors on multivariable analysis for pulmonary metastasectomy. Diffusing capacity of the lungs for carbon monoxide less than 80 per cent (HR 1.04, 95 per cent c.i. 1.01 to 1.06; P = 0.004) was the only prognostic factor on multivariable analysis for repeat metastasectomy.

CONCLUSION

This study demonstrates that patients with colorectal pulmonary metastases have comparable median and 5-year overall survival rates after primary or recurrent pulmonary metastasectomy. However, repeat metastasectomy has a higher risk of postoperative complications.

Practice variation and outcomes of minimally invasive minor liver resections in patients with colorectal liver metastases: a population-based study

INTRODUCTION

In 2017, the Southampton guideline stated that minimally invasive liver resections (MILR) should considered standard practice for minor liver resections. This study aimed to assess recent implementation rates of minor MILR, factors associated with performing MILR, hospital variation, and outcomes in patients with colorectal liver metastases (CRLM).

METHODS

This population-based study included all patients who underwent minor liver resection for CRLM in the Netherlands between 2014 and 2021. Factors associated with MILR and nationwide hospital variation were assessed using multilevel multivariable logistic regression. Propensity-score matching (PSM) was applied to compare outcomes between minor MILR and minor open liver resections. Overall survival (OS) was assessed with Kaplan-Meier analysis on patients operated until 2018.

RESULTS

Of 4,488 patients included, 1,695 (37.8%) underwent MILR. PSM resulted in 1,338 patients in each group. Implementation of MILR increased to 51.2% in 2021. Factors associated with not performing MILR included treatment with preoperative chemotherapy (aOR 0.61 CI:0.50-0.75, p < 0.001), treatment in a tertiary referral hospital (aOR 0.57 CI:0.50-0.67, p < 0.001), and larger diameter and number of CRLM. Significant hospital variation was observed in use of MILR (7.5% to 93.0%). After case-mix correction, six hospitals performed fewer, and six hospitals performed more MILRs than expected. In the PSM cohort, MILR was associated with a decrease in blood loss (aOR 0.99 CI:0.99-0.99, p < 0.01), cardiac complications (aOR 0.29, CI:0.10-0.70, p = 0.009), IC admissions (aOR 0.66, CI:0.50-0.89, p = 0.005), and shorter hospital stay (aOR CI:0.94-0.99, p < 0.01). Five-year OS rates for MILR and OLR were 53.7% versus 48.6%, p = 0.21.

CONCLUSION

Although uptake of MILR is increasing in the Netherlands, significant hospital variation remains. MILR benefits short-term outcomes, while overall survival is comparable to open liver surgery.

Case-mix adjustment to compare hospital performances regarding complications after cytoreductive surgery for ovarian cancer: a nationwide population-based study

OBJECTIVE

Complication rates after cytoreductive surgery are important quality indicators for hospitals that treat patients with advanced-stage ovarian cancer. Case-mix factors are patient and tumor characteristics that may influence hospital outcomes such as the complication rates. Currently, no case-mix adjustment model exists for complications after cytoreductive surgery; therefore, it is unclear whether hospitals are being compared correctly. This study aims to develop the first case-mix adjustment model for complications after surgery for advanced-stage ovarian cancer, enabling an accurate comparison between hospitals.

METHODS

This population-based study included all patients undergoing cytoreductive surgery for advanced-stage ovarian cancer registered in the Netherlands in 2017-2019. Case-mix variables were identified and assessed using logistic regressions. The primary outcome was the composite outcome measure 'complicated course'. Patients had a complicated course when at least one of the following criteria were met: (1) any complication combined with a prolonged length of hospital stay; (2) complication requiring reintervention; (3) any complication with a prolonged length of stay in the intensive care unit; or (4) 30-day mortality or in-hospital mortality during admission following surgery. Inter-hospital variation was analyzed using univariable and multivariable logistic regressions and visualized using funnel plots.

RESULTS

A total of 1822 patients were included, of which 10.7% (n=195) had a complicated course. Comorbidity and tumor stage had a significant impact on complicated course rates in multivariable logistic regression. Inter-hospital variation was not significant for case-mix factors. Complicated course rates ranged between 2.2% and 29.1%, and case-mix adjusted observed/expected ratios ranged from 0.20 to 2.67 between hospitals. Three hospitals performed outside the confidence intervals for complicated course rates. These hospitals remained outliers after case-mix adjustment.

CONCLUSION

There is variation between hospitals regarding complicated course rates after cytoreductive surgery for ovarian cancer in the Netherlands. While comorbidity and tumor stage significantly affected the complicated course rates, adjusting for case-mix factors did not significantly affect hospital outcomes. The limited impact of case-mix adjustment could be a result of the Dutch centralized healthcare model.

Textbook outcome as a composite outcome measure in laparoscopic pancreaticoduodenectomy: a multicenter retrospective cohort study

BACKGROUND

Textbook outcome (TO) is a composite outcome measure for surgical quality assessment. The aim of this study was to assess TO following laparoscopic pancreaticoduodenectomy (LPD), identify factors independently associated with achieving TO, and analyze hospital variations regarding the TO after case-mix adjustment.

METHODS

This multicenter cohort study retrospectively analyzed 1029 consecutive patients undergoing LPD at 16 high-volume pancreatic centers in China from January 2010 to August 2016. The percentage of patients achieving TO was calculated. Preoperative and intraoperative variables were compared between the TO and non-TO groups. Multivariate logistic regression was performed to identify factors independently associated with achieving TO. Hospital variations regarding the TO were analyzed by the observed/expected TO ratio after case-mix adjustment. Differences in expected TO rates between different types of hospitals were analyzed using the one-way analysis of variance test.

RESULTS

TO was achieved in 68.9% ( n =709) of 1029 patients undergoing LPD, ranging from 46.4 to 85.0% between different hospitals. Dilated pancreatic duct (>3 mm) was associated with the increased probability of achieving TO [odds ratio (OR): 1.564; P =0.001], whereas advanced age (≥75 years) and concomitant cardiovascular disease were associated with a lower likelihood of achieving TO (OR: 0.545; P =0.037 and OR: 0.614; P =0.006, respectively). The observed/expected TO ratio varied from 0.62 to 1.22 after case-mix adjustment between different hospitals, but no significant hospital variations were observed. Hospital volume, the surgeon's experience with open pancreaticoduodenectomy and minimally invasive surgery, and surpassing the LPD learning curve were significantly correlated with expected TO rates.

CONCLUSION

TO was achieved by less than 70% of patients following LPD. Dilated pancreatic ducts, advanced age, and concomitant cardiovascular disease were independently associated with achieving TO. No significant hospital variations were observed after case-mix adjustment.

Defining Textbook Outcome in liver surgery and assessment of hospital variation: A nationwide population-based study

INTRODUCTION

Textbook outcome (TO) is a composite outcome measure covering the surgical care process in a single outcome measure. TO has an advantage over single outcome parameters with low event rates, which have less discriminating impact to detect differences between hospitals. This study aimed to assess factors associated with TO, and evaluate hospital and network variation after case-mix correction in TO rates for liver surgery.

METHODS

This was a population-based retrospective study of all patients who underwent liver resection for malignancy in the Netherlands in 2019 and 2020. TO was defined as absence of severe postoperative complications, mortality, prolonged length of hospital stay, and readmission, and obtaining adequate resection margins. Multivariable logistic regression was used for case-mix adjustment.

RESULTS

2376 patients were included. TO was accomplished in 1380 (80%) patients with colorectal liver metastases, in 192 (76%) patients with other liver metastases, in 183 (74%) patients with hepatocellular carcinoma and 86 (51%) patients with biliary cancers. Factors associated with lower TO rates for CRLM included ASA score ≥3 (aOR 0.70, CI 0.51-0.95 p = 0.02), extrahepatic disease (aOR 0.64, CI 0.44-0.95, p = 0.02), tumour size >55 mm on preoperative imaging (aOR 0.56, CI 0.34-0.94, p = 0.02), Charlson Comorbidity Index ≥2 (aOR 0.73, CI 0.54-0.98, p = 0.04), and major liver resection (aOR 0.50, CI 0.36-0.69, p < 0.001). After case-mix correction, no significant hospital or oncological network variation was observed.

CONCLUSION

TO differs between indications for liver resection and can be used to assess between hospital and network differences.

Interregional practice variations in the use of local therapy for synchronous colorectal liver metastases in the Netherlands

BACKGROUND

The aim of this study was to evaluate the Dutch regional practice variation in treatment of synchronous colorectal liver metastases (CRLM) over time and assess their impact on patients survival.

METHODS

Two cohorts of patients with synchronous CRLM were selected from the Netherlands Cancer Registry (NCR). All patients diagnosed between 2014 and 2018 were selected to analyze interregional practice variations in local therapy (LT) with multivariable logistic regression. Overall survival (OS) was assessed for patients diagnosed from 2008 to 2013 using Kaplan Meier method and Cox regression analyses.

RESULTS

The proportion of patients who underwent LT increased from 15.5% to 21.9%. Interregional use of LT varied from 19.1% to 25.0%. Multivariable logistic regression showed significant differences between regions in the use of LT (p = 0.001) in 2014-2018. There was no association between OS and region of diagnosis for patients who underwent LT after correction for confounders.The use of LT for CRLM increased from 15.5% in 2008-2013 to 21.9% in 2014-2018. Three-year OS increased from 16% to 19% respectively.

CONCLUSION

Interregional practice variations have decreased. The remaining differences are not associated with OS. The use of local therapy and 3-year overall survival have increased over time. Local practice should be monitored to prevent undesirable variation in outcomes.

Case-mix adjustment to compare colonoscopy performance between endoscopy centers: a nationwide registry study

BACKGROUND : Nonmodifiable patient and endoscopy characteristics might influence colonoscopy performance. Differences in these so-called case-mix factors are likely to exist between endoscopy centers. This study aimed to examine the importance of case-mix adjustment when comparing performance between endoscopy centers. METHODS : Prospectively collected data recorded in the Dutch national colonoscopy registry between 2016 and 2019 were retrospectively analyzed. Cecal intubation rate (CIR) and adequate bowel preparation rate (ABPR) were analyzed. Additionally, polyp detection rate (PDR) was studied in screening colonoscopies following a positive fecal immunochemical test (FIT). Variation in case-mix factors between endoscopy centers and expected outcomes for each performance measure were calculated per endoscopy center based on case-mix factors (sex, age, American Society of Anesthesiologist [ASA] score, indication) using multivariable logistic regression. RESULTS:  363 840 colonoscopies were included from 51 endoscopy centers. Mean percentages per endoscopy center were significantly different for age > 65 years, male patients, ASA ≥ III, and diagnostic colonoscopies (all P < 0.001). In the FIT-positive screening population, significant differences were observed between endoscopy centers for age > 65 years, male patients, and ASA ≥ III (all P ≤ 0.001). The expected CIR, ABPR, and PDR ranged from 95.0 % to 96.9 %, from 93.6 % to 96.4 %, and from 76.2 % to 79.1 %, respectively. Age, sex, ASA classification, and indication were significant case-mix factors for CIR and ABPR. In the FIT-positive screening population, age, sex, and ASA classification were significant case-mix factors for PDR. CONCLUSION:  Our findings emphasize the importance of considering case-mix adjustment when comparing colonoscopy performance measures between endoscopy centers.

Development of a data-driven case-mix adjustment model for comparison of hospital performance in hip fracture care

To compare hospitals' hip fracture patient mortality in a quality of care registry, correction for patient characteristics is needed. This study evaluates in 39,374 patients which characteristics are associated with 30 and 90-day mortality, and showed how using these characteristics in a case mix-model changes hospital comparisons within the Netherlands.

PURPOSE

Mortality rates after hip fracture surgery are considerable and may be influenced by patient characteristics. This study aims to evaluate hospital variation regarding patient demographics and disease burden, to develop a case-mix adjustment model to analyse differences in hip fracture patients' mortality to calculate case-mix adjusted hospital-specific mortality rates.

METHODS

Data were derived from 64 hospitals participating in the Dutch Hip Fracture Audit (DHFA). Adult hip fracture patients registered in 2017-2019 were included. Variation of case-mix factors between hospitals was analysed, and the association between case-mix factors and mortality at 30 and 90 days was determined through regression models.

RESULTS

There were 39,374 patients included. Significant variation in case-mix factors amongst hospitals was found for age ≥ 80 (range 25.8-72.1% p < 0.001), male gender (12.0-52.9% p < 0.001), nursing home residents (42.0-57.9% p < 0.001), pre-fracture mobility aid use (9.9-86.7% p < 0,001), daily living dependency (27.5-96.5% p < 0,001), ASA-class ≥ 3 (25.8-83.3% p < 0.001), dementia (3.6-28.6% p < 0.001), osteoporosis (0.0-57.1% p < 0.001), risk of malnutrition (0.0-29.2% p < 0.001) and fracture types (all p < 0.001). All factors were associated with 30- and 90-day mortality. Eight hospitals showed higher and six showed lower 30-day mortality than expected based on their case-mix. Six hospitals showed higher and seven lower 90-day mortality than expected. The specific outlier hospitals changed when correcting for case-mix factors.

CONCLUSIONS

Dutch hospitals show significant case-mix variation regarding hip fracture patients. Case-mix adjustment is a prerequisite when comparing hospitals' 30-day and 90-day hip fracture patients' mortality. Adjusted mortality may serve as a starting point for improving hip fracture care.

Nationwide oncological networks for resection of colorectal liver metastases in the Netherlands: Differences and postoperative outcomes

INTRODUCTION

Widespread differences in patient demographics and disease burden between hospitals for resection of colorectal liver metastases (CRLM) have been described. In the Netherlands, networks consisting of at least one tertiary referral centre and several regional hospitals have been established to optimize treatment and outcomes. The aim of this study was to assess variation in case-mix, and outcomes between these networks.

METHODS

This was a population-based study including all patients who underwent CRLM resection in the Netherlands between 2014 and 2019. Variation in case-mix and outcomes between seven networks covering the whole country was evaluated. Differences in case-mix, expected 30-day major morbidity (Clavien-Dindo ≥3a) and 30-day mortality between networks were assessed.

RESULTS

In total 5383 patients were included. Thirty-day major morbidity was 5.7% and 30-day mortality was 1.5%. Significant differences between networks were observed for Charlson Comorbidity Index, ASA 3+, previous liver resection, liver disease, preoperative MRI, preoperative chemotherapy, ≥3 CRLM, diameter of largest CRLM ≥55 mm, major resection, combined resection and ablation, rectal primary tumour, bilobar and extrahepatic disease. Uncorrected 30-day major morbidity ranged between 3.3% and 13.1% for hospitals, 30-day mortality ranged between 0.0% and 4.5%. Uncorrected 30-day major morbidity ranged between 4.4% and 6.0% for networks, 30-day mortality ranged between 0.0% and 2.5%. No negative outliers were observed after case-mix correction.

CONCLUSION

Variation in case-mix and outcomes are considerably smaller on a network level as compared to a hospital level. Therefore, auditing is more meaningful at a network level and collaboration of hospitals within networks should be pursued.

The use and clinical outcome of total pancreatectomy in the United States, Germany, the Netherlands, and Sweden

BACKGROUND

Total pancreatectomy has high morbidity and mortality and differences among countries are currently unknown. This study compared the use and postoperative outcomes of total pancreatectomy among 4 Western countries.

METHODS

Patients who underwent one-stage total pancreatectomy were included from registries in the United States, Germany, the Netherlands, and Sweden (2014-2018). Use of total pancreatectomy was assessed by calculating the ratio total pancreatectomy to pancreatoduodenectomy. Primary outcomes were major morbidity (Clavien Dindo ≥3) and in-hospital mortality. Predictors for the primary outcomes were assessed in multivariable logistic regression analyses. Sensitivity analysis assessed the impact of volume (low-volume <40 or high-volume ≥40 pancreatoduodenectomies annually; data available for the Netherlands and Germany).

RESULTS

In total, 1,579 patients underwent one-stage total pancreatectomy. The relative use of total pancreatectomy to pancreatoduodenectomy varied up to fivefold (United States 0.03, Germany 0.15, the Netherlands 0.03, and Sweden 0.15; P < .001). Both the indication and several baseline characteristics differed significantly among countries. Major morbidity occurred in 423 patients (26.8%) and differed (22.3%, 34.9%, 38.3%, and 15.9%, respectively; P < .001). In-hospital mortality occurred in 85 patients (5.4%) and also differed (1.8%, 10.2%, 10.8%, 1.9%, respectively; P < .001). Country, age ≥75, and vascular resection were predictors for in-hospital mortality. In-hospital mortality was lower in high-volume centers in the Netherlands (4.9% vs 23.1%; P = .002), but not in Germany (9.8% vs 10.6%; P = .733).

CONCLUSION

Considerable differences in the use of total pancreatectomy, patient characteristics, and postoperative outcome were noted among 4 Western countries with better outcomes in the United States and Sweden. These large, yet unexplained, differences require further research to ultimately improve patient outcome.