Disparities in Receipt of Bariatric Surgery in Canada: An Analysis of Data From an Ontario Bariatric Surgery Referral Center.

BACKGROUND: Patients with lower socioeconomic status (SES) in the United States have reduced access to many health services including bariatric surgery. It is unclear whether disparities in bariatric surgery exist in countries with government-sponsored universal health benefits. The authors used data from a large regional Canadian bariatric surgery referral center to examine the relationship between SES and receipt of bariatric surgery. METHODS: The Toronto Western Hospital bariatric surgery registry was used to identify all adults referred for bariatric surgery assessment from 2010 to 2017. The authors compared demographics, SES measures, and clinical measures among patients who did not and did undergo bariatric surgery (Roux-en-Y or sleeve gastrectomy). Multiple logistic regression was used to examine differences in receipt of bariatric surgery according to patient demographic characteristics and SES factors. RESULTS: Among 2417 patients included in the study, 646 (26.7%) did not receive surgery and 1771 patients (73.2%) did. Patients who did not undergo surgery were more likely to be male individual (29.1% vs. 19.3%; P<0.001), black (12.1% vs. 8.3%; P=0.005), South Asian/Middle Eastern (8.2% vs. 4.5%; P<0.001), and less likely to be white (68.9% vs. 76.7%; P<0.001). In multiple logistic regression, factors associated with not receiving surgery were male sex, Black and South Asian/Middle Eastern ethnicity, being single, lack of employment, and history of psychiatric illness. CONCLUSIONS: Among patients referred for bariatric surgery, those who were male individuals, nonwhite, single, and unemployed were less likely to undergo surgery. Our results suggest that even with equal insurance, there are disparities in receipt of bariatric surgery.

Can Patient Selection Explain the Obesity Paradox in Orthopaedic Hip Surgery? An Analysis of the ACS-NSQIP Registry.

BACKGROUND: The "obesity paradox" is a phenomenon described in prior research in which patients who are obese have been shown to have lower postoperative mortality and morbidity compared with normal-weight individuals. The paradox is that clinical experience suggests that obesity is a risk factor for difficult wound healing and adverse cardiovascular outcomes. We suspect that the obesity paradox may reflect selection bias in which only the healthiest patients who are obese are offered surgery, whereas nonobese surgical patients are comprised of both healthy and unhealthy individuals. We questioned whether the obesity paradox (decreased mortality for patients who are obese) would be present in nonurgent hip surgery in which patients can be carefully selected for surgery but absent in urgent hip surgery where patient selection is minimized. QUESTIONS/PURPOSES: (1) What is the association between obesity and postoperative mortality in urgent and nonurgent hip surgery? (2) How is obesity associated with individual postoperative complications in urgent and nonurgent hip surgery? (3) How is underweight status associated with postoperative mortality and complications in urgent and nonurgent hip surgery? METHODS: We used 2011 to 2014 data from the American College of Surgeons National Surgical Quality Improvement Project (ACS-NSQIP) to identify all adults who underwent nonurgent hip surgery (n = 63,148) and urgent hip surgery (n = 29,047). We used logistic regression models, controlling for covariants including age, sex, anesthesia risk, and comorbidities, to examine the relationship between body mass _index (BMI) category (classified as underweight < 18.5 kg/m, normal 18.5-24.9 kg/m, overweight 25-29.9 kg/m, obese 30-39.9 kg/m, and morbidly obese > 40 kg/m) and adverse outcomes including 30-day mortality and surgical complications including wound complications and cardiovascular events. RESULTS: For patients undergoing nonurgent hip surgery, regression models demonstrate that patients who are morbidly obese were less likely to die within 30 days after surgery (odds ratio [OR], 0.12; 95% confidence interval [CI], 0.01-0.57; p = 0.038) compared with patients with normal BMI, consistent with the obesity paradox. For patients undergoing urgent hip surgery, patients who are morbidly obese had similar odds of death within 30 days compared with patients with normal BMI (OR, 1.18; 95% CI, 0.76-1.76; p = 0.54). Patients who are morbidly obese had higher odds of wound complications in both nonurgent (OR, 4.93; 95% CI, 3.68-6.65; p < 0.001) and urgent cohorts (OR, 4.85; 95% CI, 3.27-7.01; p < 0.001) compared with normal-weight patients. Underweight patients were more likely to die within 30 days in both nonurgent (OR, 3.79; 95% CI, 1.10-9.97; p = 0.015) and urgent cohorts (OR, 1.47; 95% CI, 1.23-1.75; p < 0.001) compared with normal-weight patients. CONCLUSIONS: Patients who are morbidly obese appear to have a reduced risk of death in 30 days after nonurgent hip surgery, but not for urgent hip surgery. Our results suggest that the obesity paradox may be an artifact of selection bias introduced by careful selection of the healthiest patients who are obese for elective hip surgery. Surgeons should continue to consider obesity a risk factor for postoperative mortality and complications such as wound infections for both urgent and nonurgent surgery. LEVEL OF EVIDENCE: Level III, therapeutic study.

Complications of the Arteriovenous Fistula: A Systematic Review.

The implementation of patient-centered care requires an individualized approach to hemodialysis vascular access, on the basis of each patient's unique balance of risks and benefits. This systematic review aimed to summarize current literature on fistula risks, including rates of complications, to assist with patient-centered decision making. We searched Medline from 2000 to 2014 for English-language studies with prospectively captured data on ≥100 fistulas. We assessed study quality and extracted data on study design, patient characteristics, and outcomes. After screening 2292 citations, 43 articles met our inclusion criteria (61 unique cohorts; n>11,374 fistulas). Median complication rates per 1000 patient days were as follows: 0.04 aneurysms (14 unique cohorts; n=1827 fistulas), 0.11 infections (16 cohorts; n>6439 fistulas), 0.05 steal events (15 cohorts; n>2543 fistulas), 0.24 thrombotic events (26 cohorts; n=4232 fistulas), and 0.03 venous hypertensive events (1 cohort; n=350 fistulas). Risk of bias was high in many studies and event rates were variable, thus we could not present pooled results. Studies generally did not report variables associated with fistula complications, patient comorbidities, vessel characteristics, surgeon experience, or nursing cannulation skill. Overall, we found marked variability in complication rates, partly due to poor quality studies, significant heterogeneity of study populations, and inconsistent definitions. There is an urgent need to standardize reporting of methods and definitions of vascular access complications in future clinical studies to better inform patient and provider decision making.

Hemodialysis Arteriovenous Vascular Access Creation After Kidney Transplant Failure.

BACKGROUND: Little is known about vascular access in patients starting hemodialysis therapy after kidney transplant failure. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Adult patients (aged ≥18 years) who started hemodialysis therapy in Ontario, Canada, from January 1, 2001, through December 31, 2010, after kidney transplant failure. PREDICTOR: Patient clinical and demographic characteristics. OUTCOMES: Proportion and timing of arteriovenous (AV) vascular access creation (fistula or graft) 12 months prior and up to 24 months after starting hemodialysis therapy. MEASUREMENTS: Event rates and outcome predictors. RESULTS: Our cohort included 683 patients with a mean age of 48 years and >50% with comorbidity index score < 3. In the 12 months predialysis and 24 months postdialysis, 16% and 47% of patients had an AV access created, respectively. In the postdialysis period, 13%, 26%, and 38% of patients had an AV access creation at 3, 6, and 12 months, respectively. History of coronary artery disease, diabetes mellitus, and peritoneal dialysis use prior to transplantation were associated with a lower likelihood of AV access creation. LIMITATIONS: Residual selection bias from unmeasured variables beyond the data elements. CONCLUSIONS: In Ontario, AV access creation, both before and after starting hemodialysis therapy, is low in patients with kidney transplant failure despite their being younger and healthier compared to the overall hemodialysis population. This highlights the need for a predialysis care pathway in the transplantation clinic and an active strategy to identify this patient cohort receiving hemodialysis to align modality and access choices.

Patency rates of the arteriovenous fistula for hemodialysis: a systematic review and meta-analysis.

BACKGROUND: Advantages of the arteriovenous fistula (AVF), including long patency and few complications, were ascertained more than 2 decades ago and may not apply to the contemporary dialysis population. STUDY DESIGN: Systematic review and meta-analysis. Estimates were pooled using a random-effects model and sources of heterogeneity were explored using metaregression. SETTING & POPULATION: Patients treated with long-term hemodialysis using an AVF. SELECTION CRITERIA FOR STUDIES: English-language studies indexed in MEDLINE between 2000 and 2012 using prospectively collected data on 100 or more AVFs. PREDICTOR: Age, AVF location, and study location. OUTCOMES: Outcomes of interest were primary AVF failure and primary and secondary patency at 1 and 2 years. RESULTS: 7,011 citations were screened and 46 articles met eligibility criteria (62 unique cohorts; n = 12,383). The rate of primary failure was 23% (95% CI, 18%-28%; 37 cohorts; 7,393 AVFs). When primary failures were included, the primary patency rate was 60% (95% CI, 56%-64%; 13 studies; 21 cohorts; 4,111 AVFs) at 1 year and 51% (95% CI, 44%-58%; 7 studies; 12 cohorts; 2,694 AVFs) at 2 years. The secondary patency rate was 71% (95% CI, 64%-78%; 10 studies; 11 cohorts; 3,558 AVFs) at 1 year and 64% (95% CI, 56%-73%; 6 studies; 11 cohorts; 1,939 AVFs) at 2 years. In metaregression, there was a significant decrease in primary patency rate in studies that started recruitment in more recent years. LIMITATIONS: Low quality of studies, variable clinical settings, and variable definitions of primary AVF failure. CONCLUSIONS: In recent years, AVFs had a high rate of primary failure and low to moderate primary and secondary patency rates. Consideration of these outcomes is required when choosing a patient's preferred access type.

Vascular access creation before hemodialysis initiation and use: a population-based cohort study.

BACKGROUND AND OBJECTIVES: In Canada, approximately 17% of patients use an arteriovenous access (fistula or arteriovenous graft) at commencement of hemodialysis, despite guideline recommendations promoting its timely creation and use. It is unclear if this low pattern of use is attributable to the lack of surgical creation or a high nonuse rate. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Using large health care databases in Ontario, Canada, a population-based cohort of adult patients (≥18 years old) who initiated hemodialysis as their first form of RRT between 2001 and 2010 was studied. The aims were to (1) estimate the proportion of patients who had an arteriovenous access created before starting hemodialysis and the proportion who successfully used it at hemodialysis start, (2) test for secular trends in arteriovenous access creation, and (3) estimate the effect of late nephrology referral and patient characteristics on arteriovenous access creation. RESULTS: There were 17,183 patients on incident hemodialysis. The mean age was 65.8 years, 60% were men, and 40% were referred late to a nephrologist; 27% of patients (4556 of 17,183) had one or more arteriovenous accesses created, and the median time between arteriovenous access creation and hemodialysis start was 184 days. When late referrals were excluded, 39% of patients (4007 of 10,291) had one or more arteriovenous accesses created, and 27% of patients (2724 of 10,291) used the arteriovenous access. Since 2001, there has been a decline in arteriovenous access creation before hemodialysis initiation. Women, higher numbers of comorbidities, and rural residence were consistently associated with lower rates of arteriovenous access creation. These results persisted even after removing patients with <6 months nephrology care or who had AKI 6 months before starting hemodialysis. CONCLUSIONS: In Canada, arteriovenous access creation before hemodialysis initiation is low, even among patients followed by a nephrologist. Better understanding of the barriers and influencers of arteriovenous access creation is needed to inform both clinical care and guidelines.

Association between vascular access type and patient mortality among elderly patients on hemodialysis in Canada.

Optimal vascular access in elderly patients requires consideration of the benefits and risks in a population with increased comorbidity and mortality. Our objective was to examine the association between vascular access type and patient mortality by age category among incident adult hemodialysis patients registered in the Canadian Organ Replacement Register between 2001 and 2010. We also describe the secular trend in incident and prevalent vascular access use. We used a Cox proportional hazards model to evaluate the overall mortality in patients aged less than 65, 65-74, 75-85, and greater than 85 years who initiated hemodialysis using a central venous catheter (catheter) or arteriovenous (AV)-access (fistula or graft) using an intention-to-treat approach. The cohort of 39,721 patients consisted of 42%, 27%, 26%, and 5% of patients aged <65, 65-74, 75-85, and >85, respectively. Patients who initiated hemodialysis using an AV-access constituted 21%, 22%, 20%, and 15% of each age category. AV access use was associated with lower adjusted mortality compared with catheter use in each age category (Hazard Ratios [HR], 0.67; 95% Confidence Interval [0.62-0.72]; HR, 0.76 [0.63-0.91]; HR, 0.77 [0.64-0.93], HR, 0.73 [0.56-0.96], respectively). In Canada, use of an AV-access is associated with lower mortality across all age categories, even in the very elderly. Further studies are required to understand the patient preference, complications, and resource use when selecting access type in the elderly.