Antonia J. Henry

Socioeconomic and hospital-related predictors of amputation for critical limb ischemia

OBJECTIVE Disparities in limb salvage procedures may be driven by socioeconomic status (SES) and access to high-volume hospitals. We sought to identify SES factors associated with major amputation in the setting of critical limb ischemia (CLI). METHODS The 2003-2007 Nationwide Inpatient Sample was queried for discharges containing lower extremity revascularization (LER) or major amputation and chronic CLI (N = 958,120). The Elixhauser method was used to adjust for comorbidities. Significant predictors in bivariate logistic regression were entered into a multivariate logistic regression for the dependent variable of amputation vs LER. RESULTS Overall, 24.2% of CLI patients underwent amputation. Significant differences were seen between both groups in bivariate and multivariate analysis of SES factors, including race, income, and insurance status. Lower-income patients were more likely to be treated at low-LER-volume institutions (odds ratio [OR], 1.74; P < .001). Patients at higher-LER-volume centers (OR, 15.16; P <.001) admitted electively (OR, 2.19; P < .001) and evaluated with diagnostic imaging (OR, 10.63; P < .001) were more likely to receive LER. CONCLUSIONS After controlling for comorbidities, minority patients, those with lower SES, and patients with Medicaid were more likely receive amputation for CLI in low-volume hospitals. Addressing SES and hospital factors may reduce amputation rates for CLI.

Disparities in Vascular Surgery: Is It Biology or Environment?

Disparities in health care are well documented for several racial, ethnic, and gender groups. In peripheral arterial disease, differences in prevalence, treatment selection, treatment outcomes, and resulting quality of life have negative effects on some minority groups and women. It may be easy to document disparities, but it is harder to understand their underlying causes. Are there biologic differences between members of racial and ethnic groups that influence disease presentation and outcomes? Or is the socioeconomic environment that surrounds them the true driver of observed differences? This article reviews the evidence for racial and gender disparities in vascular surgery and presents some potential mechanisms that may explain the disparities.

Impact of hospital market competition on endovascular aneurysm repair adoption and outcomes

OBJECTIVE The share of total abdominal aortic aneurysm (AAA) repairs performed by endovascular aneurysm repair (EVAR) increased rapidly from 32% in 2001 to 65% in 2006 with considerable variation between states. We hypothesized that hospitals in competitive markets were early EVAR adopters and had improved AAA repair outcomes. METHODS Nationwide Inpatient Sample and linked Hospital Market Structure (HMS) data was queried for patients who underwent repair for nonruptured AAA in 2003. In HMS, the Herfindahl Hirschman Index (HHI, range 0-1) is a validated and widely accepted economic measure of competition. Hospital markets were defined using a variable geographic radius that encompassed 90% of discharged patients. We conducted bivariate and multivariable linear and logistic regression analyses for the dependent variable of EVAR use. A propensity score-adjusted multivariable logistic regression model was used to control for treatment bias in the assessment of competition on AAA repair outcomes. RESULTS A weighted total of 21,600 patients was included in our analyses. Patients at more competitive hospitals (lower HHI) were at increased odds of undergoing EVAR vs open repair (odds ratio, 1.127 per 0.1 decrease in HHI; P < .0127) after adjusting for patient demographics, comorbidities, and hospital level factors (bed size, teaching status, AAA repair volume, and ownership). Competition was not associated with differences in in-hospital mortality or vascular, neurologic, or other minor postoperative complications. CONCLUSIONS Greater hospital competition is significantly associated with increased EVAR adoption at a time when diffusion of this technology passed its tipping point. Hospital competition does not influence post-AAA repair outcomes. These results suggest that adoption of novel vascular technology is not solely driven by clinical indications but may also be influenced by market forces.

A systematic review of functional and quality of life assessment after major lower extremity amputation.

BACKGROUND When judging the success or failure of major lower extremity (MLE) amputation, the assessment of appropriate functional and quality of life (QOL) outcomes is paramount. The heterogeneity of the scales and tests in the current literature is confusing and makes it difficult to compare results. We provide a primer for outcome assessment after amputation and assess the need for the additional development of novel instruments. METHODS MEDLINE, EMBASE, and Google Scholar were searched for all studies using functional and QOL instruments after MLE amputation. Assessment instruments were divided into functional and QOL categories. Within each category, they were subdivided into global and amputation-specific instruments. An overall assessment of instrument quality was obtained. RESULTS The initial search revealed 746 potential studies. After a review of abstracts, 102 were selected for full review, and 40 studies were then included in this review. From the studies, 21 different assessment instruments were used 63 times. There were 14 (67%) functional measures and 7 (33%) QOL measures identified. Five (36%) of the functional instruments and 3 (43%) of the QOL measures were specific for MLE amputees. Sixteen instruments were used >1 time, but only 5 instruments were used >3 times. An additional 5 instruments were included that were deemed important by expert opinion. The 26 assessment instruments were rated. Fourteen of the best-rated instruments were then described. CONCLUSIONS The heterogeneity of instruments used to measure both functional and QOL outcomes make it difficult to compare MLE amputation outcome studies. Future researchers should seek to use high-quality instruments. Clinical and research societies should endorse the best validated instruments for future use in order to strengthen overall research in the field.

Factors predicting resource utilization and survival after major amputation

OBJECTIVE Major amputation is associated with increased short-term healthcare resource utilization (RU), early mortality, and socioeconomic status (SES) disparities. Our objective is to study patient-specific and SES-related predictors of long-term RU and survival after amputation. METHODS This retrospective analysis identified 364 adult patients who underwent index major amputation for critical limb ischemia from January 1995 through December 2000 at two tertiary centers with outcomes through December 2010. Age, gender, SES (race, income, insurance, and marital status), comorbidities (congestive heart failure [CHF], diabetes, diabetes with complications, and renal failure [RF]), subsequent procedures, cumulative length of stay (cLOS), and mortality were analyzed. Bivariate and multivariate Poisson regression for subsequent procedures and cLOS and Cox proportional hazard modeling for all-cause mortality were undertaken. RESULTS During a mean follow-up of 3.25 years, amputation patients had mean cLOS of 71.2 days per person-year (median, 17.6), 19.5 readmissions per person-year (median, 2.1), 0.57 amputation-related procedures (median, 0), and 0.31 cardiovascular procedures (median, 0). Below-knee amputation as the index procedure was performed in 70% of patients, and 25% had additional amputation procedures. Of readmissions at ≤ 30 days, 52% were amputation-related. Overall mortality during follow-up was 86.9%; 37 patients (10.2%) died within 30 days. Among patients surviving >30 days, multivariate Poisson regression demonstrated that younger age (incidence rate ratio [IRR], 0.98), public insurance (IRR, 1.63), CHF (IRR, 1.60), and RF (IRR, 2.12) were associated with increased cLOS. Diabetes with complications (IRR, 1.90) and RF (IRR, 2.47) affected subsequent amputation procedures. CHF (IRR, 1.83) and RF (IRR, 3.67) were associated with a greater number of cardiovascular procedures. Cox proportional hazard modeling indicated older age (hazard ratio [HR], 1.04), CHF (HR, 2.26), and RF (HR, 2.60) were risk factors for decreased survival. Factors associated with SES were not significantly related to the outcomes. CONCLUSIONS This study found that RU is high for amputees, and increased RU persists beyond the perioperative period. Results were similar across SES indices, suggesting higher SES may not be protective against poor outcomes when limb salvage is no longer attainable. These findings support the hypothesis that SES disparities may be more modifiable during earlier stages of care for critical limb ischemia.