Does practice make perfect?

Should we pay attention to surgeon or hospital volume in total knee arthroplasty? Evidence from a nationwide population-based study

Background

Although prior research into the relationship between volume and outcome indicates that this relationship is not linear and that an optimal volume should be specified, consensus is lacking regarding the ideal value of this optimal volume. The purposes of this study were to use a visual method to identify surgeon- and hospital-volume thresholds and to examine the relationships of surgeon and hospital volume thresholds to 30-day readmission.

Methods

A retrospective nationwide population-based study design was adopted. Patients who received total knee replacement surgery between 2007 and 2008 in any hospital in Taiwan were included. After adjusting for patient, physician, and hospital characteristics, a restricted cubic spline regression model was used to identify optimal surgeon- and hospital-volume thresholds. Further, a patient-level mixed effect model was conducted to test the respective relationships between these thresholds and 30-day readmission.

Results

A total of 30,828 patients who had received their surgeries from 1,468 surgeons in 437 hospitals were included in this study. Thresholds of 50 cases a year for surgeons and 75 cases a year for hospitals were identified using a restricted cubic spline regression model. However, only the surgeon volume threshold was associated with 30-day readmission using a patient-level mixed effect model after adjusting for patient-, surgeon- and hospital-level covariates.

Conclusions

According to the results of the restricted cubic spline models, the optimal volume thresholds for surgeons and hospitals are 50 cases and 75 cases a year, respectively. However, only the surgeon volume threshold is associated with 30-day readmission.

Effects of patient factors on inpatient mortality after complex liver, pancreatic and gastric resections

Background

There is mixed evidence that patients who receive care in hospitals with a low case volume for complex gastrointestinal and hepatobiliary operations have an increased risk of inpatient death.

Methods

A retrospective cohort study was performed of patients who had complex gastrointestinal and hepatobiliary operations in the Healthcare Cost and Utilization Project 2012 National Inpatient Sample. Multivariable weighted hierarchical generalized linear models were used to test the relationship between hospital case volume and probability of inpatient death, with detailed adjustments for the concurrent effects of differences in associated patient co‐morbidities.

Results

A total of 8260 pancreaticoduodenectomies, 2750 major hepatectomies and 3250 total gastrectomies were identified. Inpatient death occurred in 3·6 per cent of patients after pancreaticoduodenectomy, 4·9 per cent after major hepatectomy and 4·6 per cent after total gastrectomy. Mean hospital case volume was 50·6 (median 40) for pancreaticoduodenectomy, 23·6 (median 15) for major hepatectomy, 15·1 (median 10) for total gastrectomy and 70·2 (median 50) for any of the three operations. Hospital case volume was not a statistically significant predictor of mortality after any operation (all P ≥ 0·188). Patient characteristics including age and co‐morbidity were highly significant predictors of mortality (P < 0·001). No significant improvements in model performance were obtained by adding hospital case volume to any model that already included adjustments for patient‐level differences in age and co‐morbid disease, for any functional format (P ≥ 0·146 for all C statistic differences from baseline).

Conclusion

Patient co‐morbidity, not hospital case volume, was associated with significant differences in inpatient mortality following complex gastric, pancreatic and hepatobiliary resections.

Differences in Breast Cancer Survival between Public and Private Care in New Zealand: Which Factors Contribute?

Background

Patients who received private health care appear to have better survival from breast cancer compared to those who received public care. This study investigated if this applied to New Zealand women and identified factors that could explain such disparities.

Methods

This study involved all women who were diagnosed with primary breast cancer in two health regions in New Zealand, covering about 40% of the national population, between June 2000 and May 2013. Patients who received public care for primary treatment, mostly surgical treatment, were compared with those who received private care in terms of demographics, mode of presentation, disease factors, comorbidity index and treatment factors. Cox regression modelling was performed with stepwise adjustments, and hazards of breast cancer specific mortality associated with the type of health care received was assessed.

Results

Of the 14,468 patients, 8,916 (61.6%) received public care. Compared to patients treated in private care facilities, they were older, more likely to be Māori, Pacifika or Asian and to reside in deprived neighbourhoods and rural areas, and less likely to be diagnosed with early staged cancer and to receive timely cancer treatments. They had a higher risk of mortality from breast cancer (hazard ratio: 1.95; 95% CI: 1.75, 2.17), of which 80% (95% CI: 63%, 100%) was explained by baseline differences, particularly related to ethnicity, stage at diagnosis and type of loco-regional therapy. After controlling for these demographic, disease and treatment factors, the risk of mortality was still 14% higher in the public sector patients.

Conclusions

Ethnicity, stage at diagnosis and type of loco-regional therapy were the three key contributors to survival disparities between patients treated in public and private health care facilities in New Zealand. The findings underscore the need for more efforts to improve the quality, timeliness and equitability of public cancer care services.

Achieving minimum caseload requirements: an analysis of hospital quality control reports from 2004-2010

BACKGROUND

Legally mandated minimum hospital caseload requirements for certain invasive procedures, including pancreatectomy, esophagectomy, and some types of organ transplantation, have been in effect in Germany since 2004. The goal of such requirements is to improve patient care by ensuring that patients undergo certain procedures only in hospitals that have met the corresponding minimum caseload requirement. We used the case numbers published in legally mandated hospital quality control reports to determine whether the hospitals actually met the stipulated requirements.

METHOD

We performed a secondary analysis of data supplied by hospitals in their quality control reports for the years 2004, 2006, 2008, and 2010 with respect to six procedures that have a minimum caseload requirement: complex interventions on the esophagus and pancreas, total knee replacement, and hepatic, renal, and stem-cell transplantation.

RESULTS

The total case numbers for these six different procedures rose from 22 064 (0.1% of all procedures) in 2004 to 170 801 (0.9% of all procedures) in 2010. From 2006 onward, procedures to which minimum caseload requirements apply have been carried out in half of all hospitals studied. These procedures account for 0.9% of all inpatient cases in Germany. The percentage of hospitals that continue to perform certain procedures despite not having met the minimum caseload requirement ranged from 5% to 45%, depending on the type of procedure, and the percentage of cases carried out in such hospitals ranged from 1% to 15%. These values remained nearly constant for each of the six minimum caseload requirements over the 4 reporting years for which data were examined.

CONCLUSION

The establishment of minimum caseload requirements in Germany in 2004 did not lessen the number of cases performed in violation of these requirements over the period 2004 to 2010.

Which Kind of Provider's Operation Volumes Matters? Associations between CABG Surgical Site Infection Risk and Hospital and Surgeon Operation Volumes among Medical Centers in Taiwan

BACKGROUND

Volume-infection relationships have been examined for high-risk surgical procedures, but the conclusions remain controversial. The inconsistency might be due to inaccurate identification of cases of infection and different methods of categorizing service volumes. This study takes coronary artery bypass graft (CABG) surgical site infections (SSIs) as an example to examine whether a relationship exists between operation volumes and SSIs, when different SSIs case identification, definitions and categorization methods of operation volumes were implemented.

METHODS

A population-based cross-sectional multilevel study was conducted. A total of 7,007 patients who received CABG surgery between 2006 and 2008 from 19 medical centers in Taiwan were recruited. SSIs associated with CABG surgery were identified using International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9 CM) codes and a Classification and Regression Trees (CART) model. Two definitions of surgeon and hospital operation volumes were used: (1) the cumulative CABG operation volumes within the study period; and (2) the cumulative CABG operation volumes in the previous one year before each CABG surgery. Operation volumes were further treated in three different ways: (1) a continuous variable; (2) a categorical variable based on the quartile; and (3) a data-driven categorical variable based on k-means clustering algorithm. Furthermore, subgroup analysis for comorbidities was also conducted.

RESULTS

This study showed that hospital volumes were not significantly associated with SSIs, no matter which definitions or categorization methods of operation volume, or SSIs case identification approaches were used. On the contrary, the relationships between surgeon's volumes varied. Most of the models demonstrated that the low-volume surgeons had higher risk than high-volume surgeons.

CONCLUSION

Surgeon volumes were more important than hospital volumes in exploring the relationship between CABG operation volumes and SSIs in Taiwan. However, the relationships were not robust. Definitions and categorization methods of operation volume and correct identification of SSIs are important issues for future research.

Association Between Physician Caseload and Patient Outcome for Sepsis Treatment

Objective.

The purpose of this study was to investigate whether physicians with larger sepsis caseloads provide better outcomes, defined as lower in-hospital mortality rates, for patients with sepsis.

Design.

Retrospective cross-sectional study.

Method.

This study used pooled data from the 2002-2004 Taiwan National Health Insurance Research Database. A total of 48,336 patients hospitalized with a principal diagnosis of septicemia were selected and assigned to 1 of 4 caseload groups on the basis of their treating physician's sepsis caseload during the 3 years reflected in the pooled data (low caseload, less than 39 cases; medium caseload, 39–88 cases; high caseload, 89–176 cases; and very high caseload, more than 176 cases). Generalized estimating equation models were used for analysis.

Results.

Receipt of treatment from physicians in the very high, high, and medium caseload groups decreased patients' odds of inhospital mortality by 49% (95% confidence interval [CI], 0.41-0.67; P < .001 ), 40% (95% CI, 0.53-0.68; P < .001 ), and 18% (95% CI, 0.73-0.92; P < .001), respectively, compared with the odds for patients treated by low-caseload physicians. These findings persisted after partitioning out systematic physician-specific and hospital-specific variation and isolating the effects of most hospital, physician, and patient confounders.

Conclusion.

Patients treated by physicians who had a larger sepsis caseload had a substantially lower in-hospital mortality rate than did patients treated by physicians in the other caseload groups, and the difference was statistically significant. This result supports the “practice makes perfect” hypothesis.

Re-examining the significance of surgical volume to breast cancer survival and recurrence versus process quality of care in Taiwan

OBJECTIVE

This study explored the association of surgical volume versus process quality with breast cancer survival and recurrence.

DATA SOURCES/STUDY SETTING

Population-based cancer registration data and National Health Insurance claim data.

STUDY DESIGN

This population-based study linked Taiwan's Cancer Database with Taiwan's National Health Insurance Database to collect data on all patients diagnosed with breast cancer in 2003-2004 who received surgical treatment.

PRINCIPAL FINDINGS

This study included 6,396 female breast cancer patients, reported by 26 hospitals. After controlling for patient and provider characteristics, Cox's regression models did not reveal any association between a physician's surgical volume and breast cancer recurrence or survival, although hospital volume was marginally associated with positive 5-year recurrence (HR: 1.001, 95%CI: 1.000, 1.001). After controlling for hospital or physician volume of surgery, we found a significant association between quality of care and both 5-year survival and recurrence. Random effects were also identified between patients and providers based on 5-year survival and 5-year recurrence.

CONCLUSIONS

Process quality of care was significantly more related to survival or recurrence than to surgical volume. The random effects found within hospital-patient clustered data indicated that the effect of the clustered feature of this data should be considered when performing volume-outcome related studies.

The incidence and relative risk of stroke in patients with schizophrenia: a five-year follow-up study

OBJECTIVE

This study aimed to estimate the incidence and relative risk of stroke and post-stroke all-cause mortality in patients with schizophrenia.

METHODS

This study identified a study population from the National Health Insurance Research Database (NHIRD) between 1999 and 2003 that included 80,569 patients with schizophrenia and 241,707 age- and sex-matched control participants without schizophrenia. The participants were randomly selected from the 23,981,020-participant NHIRD, which consists of 96% Taiwanese participants. Participants who had experienced a stroke between 1999 and 2003 were excluded. Using data from the NHIRD between 2004 and 2008, the incidence of stroke (ICD-9-CM code 430-438) and patient survival after stroke were calculated for both groups. After adjusting for confounding risk factors, a Cox proportional-hazards model was used to compare the five-year stroke-free survival rate to the all-cause mortality rate across the two cohorts.

RESULTS

Over five years, 1380 (1.71%) patients with schizophrenia and 2954 (1.22%) controls suffered from strokes. After adjusting for demographic characteristics and comorbid medical conditions, patients with schizophrenia were 1.13 times more likely to have a stroke (95% CI=1.05-1.22; P=0.0006). In addition, 1039 (24%) patients who had a stroke died during the follow-up period. After adjusting for patient, physician and hospital variables, the all-cause mortality hazard ratio for patients with schizophrenia was 1.23 (95% CI=1.06-1.41; P=0.0052).

CONCLUSIONS

During a five-year follow-up, the likelihood of developing a stroke and the all-cause mortality rate were greater among patients with schizophrenia as compared with the control group.

Assessing the relationship between volume and outcome in hospital services: implications for service centralization

Proposals for centralizing services are often justified on the basis of studies linking the volume of activity to the outcomes achieved. However, the evidence of such studies is far from demonstrating a causal link between volume and outcome. This article assesses the main reasons why volume and outcome studies do not in themselves demonstrate a causal link, and therefore do not provide adequate support for proposals for centralizing hospital services. It then sets out a number of precepts to guide those responsible for proposing centralization of services.

Hospital volume influences the choice of operation for thyroid cancer

BACKGROUND

Many authors advocate total or near-total thyroidectomy for thyroid carcinoma. This study examined the relationship between hospital volume of thyroidectomies and choice of bilateral thyroidectomy for thyroid carcinoma.

METHODS

Data were extracted from the administrative databases of all hospital discharge abstracts in the Rhône-Alpes area of France. The study population included inpatient stays from 1999 to 2004 with a diagnosis of thyroid disease (benign or malignant) and a procedural code for thyroid surgery. Multivariable logistic regression analyses were performed to determine factors associated with the extent of surgery (unilateral versus bilateral) for thyroid carcinoma.

RESULTS

A total of 20 140 thyroidectomies were identified, including 4006 procedures for cancer. Compared with hospitals performing a high volume of procedures for all thyroid diseases (at least 100 annually), the risk of a unilateral procedure for thyroid cancer increased by 2.46 (95 per cent confidence interval 1.63 to 3.71) in low-volume hospitals (fewer than ten operations per year) and by 1.56 (1.27 to 1.92) in medium-volume centres (ten to 99 per year).

CONCLUSION

There is a significant relationship between hospital volume and the decision to perform bilateral surgery for thyroid carcinoma. Thyroid cancer surgery should be performed by experienced surgical teams in high-volume centres.

Socioeconomic deprivation adversely affects survival of patients with rectal cancer

Background

The aim was to examine the influence of socioeconomic deprivation on stage at presentation, perioperative mortality, permanent stoma rates and overall survival in patients with rectal cancer.

Methods

Data on patient demographics, mode and stage of presentation, and short- and longer-term outcomes were extracted from a database of patients with rectal cancer. Comparisons were made after stratification into quintiles of socioeconomic deprivation.

Results

In total 486 patients were identified. Fewer patients from the most deprived group than from the least deprived group underwent resectional surgery (79·2 versus 93 per cent; P = 0·005). Permanent stoma rates among patients who had surgery were 40·8 and 30 per cent respectively (P = 0·110). The overall 5-year survival rate was 32·8 per cent for the most deprived compared with 64·0 per cent for the least deprived patients (P &lt; 0·001). Respective rates for those who underwent resectional surgery were 49·9 and 72 per cent (P = 0·030).

Conclusion

In rectal cancer, socioeconomic deprivation appears to be associated with poorer outcomes and survival. This has important implications for healthcare planning.