Dataset Information

Comparison of Rates of Lower Extremity Amputation in Patients With and Without Gout in the US Department of Veterans Affairs Health System.

ABSTRACT:

Importance

Cardiometabolic and other risk factors could render patients with gout more likely to undergo lower extremity amputation (LEA).

Objective

To examine the rate of and factors associated with LEA in patients with gout.

Design, setting, and participants

In this matched cohort study using national administrative data, multivariable Cox proportional hazards regression models were used to examine the associations of gout with LEA. In analyses limited to patients with gout, attributes of serum urate control and treatment with urate-lowering therapy were examined as factors associated with LEA. This study included patients who used US Department of Veterans Affairs services from January 1, 2000, to July 31, 2015. Patients with gout were identified using diagnostic codes and matched with up to 10 controls by age, sex, and year of benefit enrollment. Data analysis was performed from January 26, 2021, to September 3, 2021.

Exposures

Gout classification served as the primary independent variable of interest. In analyses limited to patients with gout, factors associated with serum urate control and urate-lowering therapy were examined.

Main outcomes and measures

Overall LEA, as well as toe, transmetatarsal, below-the-knee, and above-the-knee amputation.

Results

This cohort study included 5 924 918 patients, 556 521 with gout (mean [SD] age, 67 [12] years; 550 963 (99.0%) male; 88 853 [16.0%] Black non-Hispanic; 16 981 [4.3%] Hispanic/Latinx; 345 818 [62.1%] White non-Hispanic; 80 929 [14.5%] with race and ethnicity data missing; and 23 940 [4.3%] classified as other) and 5 368 397 without gout (mean [SD] age, 67 [12] years; 5 314 344 [99.0%] male; 558 464 [10.4%] Black non-Hispanic; 204 291 [3.0%] Hispanic/Latinx; 3 188 504 [59.4%] White non-Hispanic; 1 257 739 [23.4%)] with race and ethnicity data missing; and 159 399 [3.0%] classified as other). Compared with patients without gout, patients with gout were more likely to undergo amputation, an increased rate that remained after adjustment (adjusted hazard ratio, 1.20; 95% CI, 1.16-1.24) and was highest for below-the-knee amputation (adjusted hazard ratio, 1.59; 95% CI, 1.39-1.81). In those with gout, poor serum urate control (mean >7 mg/dL during the preceding year) was associated with a 25% to 37% increase in the rate of amputation. In contrast, treatment with urate-lowering therapy was not associated with the LEA rate.

Conclusions and relevance

In this matched cohort study, patients with gout were more likely to undergo LEA. This increase was independent of other comorbidities that have been associated with amputation, including diabetes and peripheral vascular disease. Serum urate control was independently associated with the LEA rate, suggesting the possibility that lower extremity amputation may be preventable in some patients.

SUBMITTER: Mikuls TR

PROVIDER: S-EPMC8739736 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Background Rates of major lower extremity amputation in patients with peripheral artery disease are higher in rural communities with markers of low socioeconomic status, but most Americans live in metropolitan areas. Whether amputation rates vary within US metropolitan areas is unclear, as are characteristics of high amputation rate urban communities. Methods and Results We estimated rates of major lower extremity amputation per 100 000 Medicare beneficiaries between 2010 and 2018 at the ZIP code level among ZIP codes with ≥100 beneficiaries. We described demographic characteristics of high and low amputation ZIP codes, and the association between major amputation rate and 3 ZIP code-level markers of socioeconomic status-the proportion of patients with dual eligibility for Medicaid, median household income, and Distressed Communities Index score-for metropolitan, micropolitan, and rural ZIP code cohorts. Between 2010 and 2018, 188 995 Medicare fee-for-service patients living in 31 391 ZIP codes with ≥100 beneficiaries had a major lower extremity amputation. The median (interquartile range) ZIP code-level number of amputations per 100 000 beneficiaries was 262 (75-469). Though nonmetropolitan ZIP codes had higher rates of major amputation than metropolitan areas, 78.2% of patients undergoing major amputation lived in metropolitan areas. Compared with ZIP codes with lower amputation rates, top quartile amputation rate ZIP codes had a greater proportion of Black residents (4.4% versus 17.5%, P<0.001). In metropolitan areas, after adjusting for clinical comorbidities and demographics, every $10 000 lower median household income was associated with a 4.4% (95% CI, 3.9-4.8) higher amputation rate, and a 10-point higher Distressed Communities Index score was associated with a 3.8% (95% CI, 3.4%-4.2%) higher amputation rate; there was no association between the proportion of patients eligible for Medicaid and amputation rate. These findings were comparable to the associations identified across all ZIP codes. Conclusions In metropolitan areas, where most individuals undergoing lower extremity amputation live, markers of lower socioeconomic status and Black race were associated with higher rates of major lower extremity amputation. Development of community-based tools for peripheral artery disease diagnosis and management targeted to communities with high amputation rates in urban areas may help reduce inequities in peripheral artery disease outcomes.

Project description:ImportanceLower extremity amputation (LEA) is associated with significant morbidity and mortality. However, national temporal trends of LEA incidence rates among US veterans and associated factors have not been well characterized.ObjectiveTo describe the temporal trends of LEA, characterize associated risk factors, and decompose the associations of these risk factors with changes in temporal trends of LEA among US veterans using Department of Veteran Affairs (VA) services between 2008 and 2018.Design, setting, and participantsThis cohort study used VA data from 2008 to 2018 to estimate incidence rates of LEA among veterans using VA services. Cox regression models were used to identify risk factors associated with LEA. Decomposition analyses estimated the associations of changes in prevalence of risk factors with changes in LEA rates. Data were analyzed from October 1, 2007, to September 30, 2018.Main outcomes and measuresToe, transmetatarsal, below-knee, or above-knee LEA.ResultsA total of 6 493 141 veterans were included (median [interquartile range] age, 64 [54-76] years; 6 060 390 [93.4%] men). Veterans were studied for a median (interquartile range) of 10.9 (5.6-11.0) years. Between 2008 and 2018, rates of LEA increased from 12.89 (95% CI, 12.53-13.25) LEA per 10 000 persons to 18.12 (95% CI, 17.70-18.54) LEA per 10 000 persons, representing a net increase of 5.23 (95% CI, 4.68-5.78) LEA per 10 000 persons. Between 2008 and 2018, toe amputation rates increased by 3.24 (2.89-3.59) amputations per 10 000 persons, accounting for 62.0% of the total increase in LEA rates. Transmetatarsal amputations increased by 1.54 (95% CI, 1.27-1.81) amputations per 10 000 persons; below-knee amputation rates increased by 0.81 (95% CI, 0.56-1.05) amputations per 10 000 persons; and above-knee amputation rates decreased by 0.37 (95% CI, 0.14-0.59) amputations per 10 000 persons. Compared with men, women had decreased risk of any LEA (hazard ratio [HR], 0.34 [95% CI, 0.31-0.37]). Factors associated with increased risk of any LEA included Black race (HR, 1.25 [95% CI, 1.21-1.28]) or another non-White race (ie, Asian, Latino, or other; HR, 2.36 [95% CI, 2.30-2.42]), obesity (HR, 1.59 [95% CI, 1.55-1.63]), diabetes (HR, 6.38 [95% CI, 6.22-6.54]), chronic kidney disease (CKD; eg, CKD stage 5: HR, 3.94 [95% CI, 3.22-4.83]), and smoking status (eg, current smoking: HR, 1.97 [95% CI, 1.92-2.03]). Decomposition analyses suggested that while changes in demographic composition, primarily driven by increased proportion of women veterans, associated with a decrease of 0.18 (95% CI, 0.14-0.22) LEA per 10 000 persons, and decreases in smoking rates, associated with a decrease of 0.88 (95% CI, 0.79-0.97) LEA per 10 000 persons. However, these were overwhelmed by increased rates of diabetes, associated with an increase of 1.86 (95% CI, 1.72-1.99) LEA per 10 000 persons; peripheral arterial disease, associated with an increase of 1.53 (95% CI, 1.41-1.65) LEA per 10 000 persons; CKD, associated with an increase of 1.45 (95% CI, 1.33-1.57) LEA per 10 000 persons; and other clinical factors, including body mass index, cancer, cardiovascular disease, cerebrovascular disease, chronic lung disease, dementia, and hypertension, associated with an increase of 1.45 (95% CI, 1.33-1.57) LEA per 10 000 persons.Conclusions and relevanceThis cohort study found that incidence rates of LEA among veterans using VA services increased between 2008 and 2018. Efforts aimed at reducing burden of LEA should target the reduction of diabetes, peripheral arterial disease, and CKD at the individual and population levels.

Project description:Importance:Patients with end-stage renal disease (ESRD) who receive dialysis are at high risk of lower extremity amputation. Recent studies indicate decreasing rates of lower extremity amputation in non-ESRD populations, but contemporary data for patients with ESRD who receive dialysis are lacking. Objectives:To assess rates of lower extremity amputation among patients with ESRD who receive dialysis during a recent 15-year period; to analyze whether those rates differed by age, sex, diabetes, or geographic region; and to determine 1-year mortality rates in this population after lower extremity amputation. Design, Setting, and Participants:This retrospective study of 3?700?902 records obtained from a US national registry of patients with ESRD who receive dialysis assessed cross-sectional cohorts for each calendar year from 2000 through 2014. Adult patients with prevalent ESRD treated with hemodialysis or peritoneal dialysis covered by Medicare Part A and B on January 1 of each cohort year were included. Data analysis was conducted from August 2017 to April 2018. Exposures:Age, sex, diabetes, and hospital referral region. Main Outcomes and Measures:Annual rates per 100 person-years of nontraumatic major (above- or below-knee) and minor (below-ankle) amputations. Results:For each annual cohort, there were fewer women (47.5% in 2000, 46.2% in 2005, 44.9% in 2010, and 44.0% in 2014) than men, more than half the patients were white individuals (58.1% in 2000, 56.9% in 2005, 56.9% in 2010, and 56.7% in 2014), and a small proportion were employed (13.9% in 2000, 15.1% in 2005, 16.1% in 2010, and 16.5% in 2014). The rate of lower extremity amputations for patients with ESRD who receive dialysis decreased by 51.0% from 2000 to 2014, driven primarily by a decrease in the rate of major amputations (5.42 [95% CI, 5.28-5.56] in 2000 vs 2.66 [95% CI, 2.59-2.72] per 100 person-years in 2014). Patients with diabetes had amputation rates more than 5 times as high as patients without diabetes. Patients younger than 65 years had higher adjusted amputation rates than older patients, and men had consistently higher adjusted amputation rates than women. Adjusted 1-year mortality rates after lower extremity amputation for patients with ESRD who receive dialysis decreased from 52.2% (95% CI, 50.9%-53.4%) in 2000 to 43.6% (95% CI, 42.5%-44.8%) in 2013. In general, amputation rates decreased among all regions from 2000 to 2014, but regional variability persisted across time despite adjustment for differences in patient demographics and comorbid conditions. Conclusions and Relevance:Although rates of lower extremity amputations among US patients with ESRD who receive dialysis decreased by 51% during a recent 15-year period, mortality rates remained high, with nearly half of patients dying within a year after lower extremity amputation. Our results highlight the need for more research on ways to prevent lower extremity amputation in this extremely high-risk population.

Project description:Lower extremity amputation is often performed in patients where both lower extremities are at risk due to peripheral arterial disease or diabetes, yet the proportion of patients who progress to amputation of their contralateral limb is not well defined. We sought to determine the rate of subsequent amputation on both the ipsilateral and contralateral lower extremities following initial amputation.We conducted a retrospective review of all patients undergoing lower extremity amputation (exclusive of trauma or tumor) at our institution from 1998 to 2010. We used International Classification of Diseases-Ninth Revision codes to identify patients and procedures as well as comorbidities. Outcomes included the proportion of patients at 1 and 5 years undergoing contralateral and ipsilateral major and minor amputation stratified by initial major vs minor amputation. Cox proportional hazards regression analysis was performed to determine predictors of major contralateral amputation.We identified 1715 patients. Mean age was 67.2 years, 63% were male, 77% were diabetic, and 34% underwent an initial major amputation. After major amputation, 5.7% and 11.5% have a contralateral major amputation at 1 and 5 years, respectively. After minor amputation, 3.2% and 8.4% have a contralateral major amputation at 1 and 5 years while 10.5% and 14.2% have an ipsilateral major amputation at 1 and 5 years, respectively. Cox proportional hazards regression analysis revealed end-stage renal disease (hazard ratio [HR], 3.9; 95% confidence interval [CI], 2.3-6.5), chronic renal insufficiency (HR, 2.2; 95% CI, 1.5-3.3), atherosclerosis without diabetic neuropathy (HR, 2.9; 95% CI, 1.5-5.7), atherosclerosis with diabetic neuropathy (HR, 9.1; 95% CI, 3.7-22.5), and initial major amputation (HR, 1.8; 95% CI, 1.3-2.6) were independently predictive of subsequent contralateral major amputation.Rates of contralateral limb amputation are high and predicted by renal disease, atherosclerosis, and atherosclerosis with diabetic neuropathy. Physicians and patients should be alert to the high risk of subsequent amputation in the contralateral leg. All patients, but particularly those at increased risk, should undergo close surveillance and counseling to help prevent subsequent amputations in their contralateral lower extremity.