G.A. Gooiker

Systematic review and meta‐analysis of the volume–outcome relationship in pancreatic surgery

Many studies have shown lower mortality and higher survival rates after pancreatic surgery with high‐volume providers, suggesting that centralization of pancreatic surgery can improve outcomes. The methodological quality of these studies is open to question. This study involves a systematic review of the volume–outcome relationship for pancreatic surgery with a meta‐analysis of studies considered to be of good quality.

The volume-outcome relation in the surgical treatment of esophageal cancer: a systematic review and meta-analysis.

This study was undertaken to conduct a systematic review and meta‐analysis of the literature on the relation between procedural volume and outcome of esophagectomies. A systematic search was carried out to identify articles investigating effects of hospital or surgeon volume on short‐term and long‐term outcomes published between 1995 and 2010. Articles were scrutinized for methodological quality, and after inclusion of only high‐quality studies, a meta‐analysis assuming a random effects model was done to estimate the effect of higher volume on patient outcome. Heterogeneity in study results was evaluated with an I2‐test and risk of publication bias with an Egger regression intercept. Forty‐three studies were found. Sixteen studies met the strict inclusion criteria for the meta‐analysis on hospital volume and postoperative mortality and 4 studies on hospital volume and survival. The pooled estimated effect size was significant for high‐volume providers in the analysis of postoperative mortality (odds ratio [OR], 2.30; 95% confidence interval [CI], 1.89‐2.80) and in the survival analysis (OR, 1.17; 95% CI, 1.05‐1.30). The meta‐analysis of surgical volume and outcome showed no significant results. Studies in which the results were adjusted not only for patient characteristics but also for tumor characteristics and urgency of the operation showed a stronger correlation between hospital volume and mortality. Also, studies performed on data from the United States showed higher effect sizes. The evidence for hospital volume as an important determinant of outcome in esophageal cancer surgery is strong. Concentration of procedures in high‐volume hospitals with a dedicated setting for the treatment of esophageal cancer might lead to an overall improvement in patient outcome. Cancer 2012;.

A systematic review and meta-analysis of the relationship between hospital/surgeon volume and outcome for radical cystectomy: an update for the ongoing debate.

CONTEXT There is an ongoing debate about centralisation of radical cystectomy (RC) procedures. OBJECTIVE To conduct a systematic review of the literature on the volume-outcome relationship for RC for bladder cancer (BCa) with consideration for the methodologic quality of the available evidence and to perform a meta-analysis on the studies meeting predefined quality criteria. EVIDENCE ACQUISITION A systematic search was performed to identify all articles examining the effects of procedure volume on clinical outcome for cystectomy. Reviews, opinion articles, and surveys were excluded. All articles were critically appraised for methodologic quality and risk of bias. Meta-analysis was performed to calculate the overall effect of higher surgeon or hospital volume on patient outcome. EVIDENCE SYNTHESIS Ten studies of good methodologic quality were included for meta-analysis. Eight studies were based on administrative data, two studies on clinical data. The results showed a significant association between high-volume hospitals and low mortality. A meta-analysis of the seven studies on hospital mortality showed a pooled estimated effect of odds ratio (OR) 0.55 (range: 0.44-0.69). The result was moderate heterogeneity (I(2)=50). A large variation in cut-off points used was observed. Sensitivity analyses did not show different effects in any of the subgroup analyses. Also, no significant differences in effect sizes were observed for different cut-off points. The data were not suggestive for publication bias. One study showed a positive effect of hospital volume on survival (hazard ratio [HR]: 0.89; p=0.06). Two studies showed a beneficial effect of surgeon volume on mortality (OR: 0.55; OR: 0.64). Only one study on the impact of surgeon volume on survival was found; it showed no significant positive effect for higher volume (HR: 0.83; p=0.26). CONCLUSIONS Postoperative mortality after cystectomy is significantly inversely associated with high-volume providers. However, additional quality criteria, such as infrastructure and level of specialisation, should be formulated to direct centralisation initiatives. The Dutch Association of Urology in 2010 implemented a national quality of care (QoC) registration programme for all patients treated by surgery for muscle-invasive BCa, including multiple parameters defining QoC.

Impact of centralization of pancreatic cancer surgery on resection rates and survival

Centralization of pancreatic surgery has been shown to reduce postoperative mortality. It is unknown whether resection rates and survival have also improved. The aim of this study was to analyse the impact of nationwide centralization of pancreatic surgery on resection rates and long‐term survival.

A systematic review and meta-analysis of the volume-outcome relationship in the surgical treatment of breast cancer. Are breast cancer patients better of with a high volume provider?

AIMS To conduct a systematic review of the literature on the volume-outcome relationship for the surgical treatment of breast cancer with consideration of the methodological quality of the available evidence and to perform a meta-analysis on the studies of considered good quality. METHODS A systematic search was done to identify all articles examining the effects of hospital or surgeon volume on clinical outcome of the surgical treatment of breast cancer. Reviews, opinion articles and surveys were excluded. All articles were critically appraised on methodological quality and risk of bias. After strict inclusion, meta-analysis assuming a random effects model was done to estimate the effect of higher hospital or surgeon volume on patient outcome. RESULTS We found 12 studies of good methodological quality which could be included for meta-analysis. The results showed a significant association between high volume providers and an improved survival. The association is the most robust for surgeon volume (HR 0.80 (0.71-0.90) and RR 0.85 (0.80-0.90). In addition there is an effect of hospital volume on the in-hospital mortality, although the mortality was very low (0.1-0.2%). Results of meta-analysis were heterogeneous. Sensitivity analysis showed a larger effect size for studies also adjusting for comorbidity for both studies on hospital and surgeon volume. The data were not suggestive for publication bias. CONCLUSIONS The results show that survival after breast cancer surgery is significantly associated with high volume providers.

The Relationship Between Volume or Surgeon Specialty and Outcome in the Surgical Treatment of Lung Cancer A Systematic Review and Meta-Analysis

Background: Whether improvement of quality of surgical cancer care can be achieved by centralizing care in high-volume specialized centers is a subject of ongoing debate. We have conducted a meta-analysis of the literature on the effect of procedural volume or surgeon specialty on outcome of lung resections for cancer. Methods: A systematic search of articles published between January 1, 1990 and January 20, 2011 on the effects of surgeon specialty and hospital or surgeon volume of lung resections on mortality and survival was conducted. After strict inclusion, meta-analysis assuming a random-effects model was performed. Meta-regression was used to identify volume cutoff values. Heterogeneity and the risk of publication bias were evaluated. Results: Nineteen relevant studies were found. Studies were heterogeneous, especially in defining volume categories. The pooled estimated effect size was significant in favor of high-volume hospitals regarding postoperative mortality (odds ratio [OR] 0.71; confidence interval 0.62–0.81), but not for survival (OR 0.93; confidence interval 0.84–1.03). Surgeon volume showed no significant effect on outcome. General surgeons had significantly higher mortality risks than general thoracic (OR 0.78; 0.70–0.88) or cardiothoracic surgeons (OR 0.82; 0.69–0.96). A minimal annual volume of resections for lung cancer could not be identified. Conclusions: Hospital volume and surgeon specialty are important determinants of outcome in lung cancer resections, but evidence-based minimal-volume standards are lacking. Evaluation of individual institutions in a national audit program might help elucidate the influence of individual quality-of-care parameters, including hospital volume, on outcome.

Successful and safe introduction of laparoscopic colorectal cancer surgery in Dutch hospitals

Objective:To investigate the safety of laparoscopic colorectal cancer resections in a nationwide population-based study. Background:Although laparoscopic techniques are increasingly used in colorectal cancer surgery, little is known on results outside trials. With the fast introduction of laparoscopic resection (LR), questions were raised about safety. Methods:Of all patients who underwent an elective colorectal cancer resection in 2010 in the Netherlands, 93% were included in the Dutch Surgical Colorectal Audit. Short-term outcome after LR, open resection (OR), and converted LR were compared in a generalized linear mixed model. We further explored hospital differences in LR and conversion rates. Results:A total of 7350 patients, treated in 90 hospitals, were included. LR rate was 41% with a conversion rate of 15%. After adjustment for differences in case-mix, LR was associated with a lower risk of mortality (odds ratio 0.63, P < 0.01), major morbidity (odds ratio 0.72, P < 0.01), any complications (odds ratio 0.74, P < 0.01), hospital stay more than 14 days (odds ratio 0.71, P < 0.01), and irradical resections (odds ratio 0.68, P < 0.01), compared to OR. Outcome after conversion was similar to OR (P > 0.05). A large variation in LR and conversion rates among hospitals was found; however, the difference in outcome associated with operative techniques was not influenced by hospital of treatment. Conclusions:Use of laparoscopic techniques in colorectal cancer surgery in the Netherlands is safe and results are better in short-term outcome than open surgery, irrespective of the hospital of treatment. Outcome after conversion was similar to OR.

Risk Factors for Excess Mortality in the First Year After Curative Surgery for Colorectal Cancer

BackgroundThirty-day mortality after surgery for colorectal cancer may vastly underestimate 1-year mortality. This study aimed to quantify the excess mortality in the first postoperative year of stage I–III colorectal cancer patients and to identify risk factors for excess mortality.MethodsAll 2,131 patients who were operated with curative intent for stage I–III colorectal cancer in the western region of the Netherlands between January 1, 2006, and December 31, 2008, were analyzed. Thirty-day mortality and relative survival were calculated. In addition, relative excess risk (RER) of death was estimated by a multivariable model.ResultsThirty-day mortality was 4.9%. One-year mortality was 12.4%. Risk factors for excess mortality in the first postoperative year for colon cancer patients were emergency surgery (excess mortality 29.7%, RER 2.5, 95% confidence interval 2.5–5.0), a Charlson score of >1 (excess mortality 12.6%, RER 2.3, 95% confidence interval 1.5–3.7), stage II or III disease (excess mortality 14.9%, RER 3.9, 95% confidence interval 1.9–8.1), and postoperative adverse events (excess mortality 22.6%, RER 2.1, 95% confidence interval 1.4–3.2).ConclusionsThe 30-day mortality rate highly underestimates the risk of dying in the first year after surgery, with excess 1-year mortality rates varying from 15 to 30%. This excess mortality was especially prominent in patients with comorbidities, higher stages of disease, emergency surgery, and postoperative surgical complications.

Cause of death the first year after curative colorectal cancer surgery; a prolonged impact of the surgery in elderly colorectal cancer patients.

BACKGROUND The 1-year mortality after colorectal cancer surgery is high and explains age related differences in colorectal cancer survival. To gain better insight in its etiology, cause of death for these patients was studied. METHODS All 1924 patients who had a resection for stage I-III colorectal cancer from 2006 to 2008 in the Western region of the Netherlands were identified. Data were merged with cause of death data from the Central Bureau of Statistics Netherlands. To calculate excess mortality as compared to the general population, national data were used. RESULTS Overall 13.2% of patients died within the first postoperative year. One-year mortality increased with age. It was as high as 43% in elderly patients that underwent emergency surgery. In 75% of patients, death was attributed to the colorectal cancer. In 25% of all patients, registered deaths were attributed to postoperative complications. Elderly patients with comorbidity more frequently died due to complications (p < 0.01). Death of other causes was similar to background mortality according to age group. CONCLUSION In the presently studied cohort of patients that died within one year of surgery, cause of death was predominantly attributed to colorectal cancer. However, because it is not to be expected that in this cohort the number of deaths from recurrences is very high, the excess 1-year mortality indicates a prolonged impact of the surgery, especially in elderly patients. Therefore, in these patients we should focus on limiting the physiological impact of the surgery and be more involved in the post-hospital period.

Volume- or outcome-based referral to improve quality of care for esophageal cancer surgery in The Netherlands

Recently, in The Netherlands esophageal resections for cancer are banned from hospitals with an annual volume less than 10. In this study we evaluate the validity of this specific volume cut‐off, based on a review of the literature and an analysis of the available data on esophagectomies in our country. In addition, we compare the expected benefits of volume‐based referral to the results of a regional centralization process based on differences in outcome (outcome‐based referral). J. Surg. Oncol. 2009;99:481–487.