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Kevin C Abbott

Publications and source records attributed to Kevin C Abbott.

81 records · Page 5Linked to original sources

Scleroderma at end stage renal disease in the United States: patient characteristics and survival.

BACKGROUND: The patient characteristics and mortality associated with scleroderma have not been characterized for a national sample of end stage renal disease (ESRD) patients. METHODS: 364,317 patients in the United States Renal Data System initiated on ESRD therapy between 1 January 1992 and 30 June 1997 with valid causes of ESRD were analyzed in an historical cohort study of scleroderma. RESULTS: Of the study population, 820 (0.22%) had scleroderma. The mean age of patients with scleroderma was 56.38 +/- 13.93 years vs. 60.48 +/- 16.51 years for patients with other causes of ESRD (p<0.01 by Student's t-test). In histogram analysis, there were two age peaks: 45-49 and 65-69. In logistic regression, patients with scleroderma, compared to patients with other causes of ESRD, were significantly more likely to be women, Caucasian, younger, and more likely to have congestive heart failure but less likely to have ischemic heart disease, stroke, and receive predialysis erythropoietin. The unadjusted two-year survival of patients with scleroderma during the study period was 49.3% vs. 63.8% in all other patients (adjusted hazard ratio, 1.96, 95% CI 1.70-2.26, p=0.0001 by Cox Regression). CONCLUSIONS: Among patients with ESRD, the demographics of patients with scleroderma were similar to those of patients with scleroderma in the general population. Patients with scleroderma had decreased survival compared to patients with other causes of ESRD, despite being equally likely to be wait listed and receive renal transplantation adjusted for other factors.

Adult↗

Risk factors for pulmonary embolism in chronic dialysis patients.

BACKGROUND: Risk factors for pulmonary embolism (PE) in end stage renal disease (ESRD) patients have not been studied in a large population. METHODS: 375,152 patients in the United States Renal Data System initiated on dialysis between 1 January 1992 and 30 June 1997 were analyzed in an historical cohort study of hospitalized PE (ICD9 Code 415.1x) occurring prior to receipt of renal transplant. Cox regression models were used to analyze risk factors for PE in dialysis. Dialysis modality was analyzed in an intention to treat fashion, thus patients who changed modalities later were considered to have remained on the same modality. RESULTS: The incidence of pulmonary embolism did not increase over time. Independent risk factors for hospitalizations for PE were similar to those in the general population (older age, females, systemic lupus erythematosus, lower risk for Asians) with the addition of peritoneal dialysis (vs. hemodialysis, adjusted odds ratio 1.56, 95% CI 1.15-2.13), polycystic kidney disease, and congestive heart failure. Notably, in Cox regression analysis, no relation was seen with baseline laboratory results (hematocrit, serum albumin, serum creatinine) or comorbidity (except congestive heart failure) and PE risk. Dialysis patients with PE had increased mortality (hazard ratio 1.20, 95% confidence interval 1.08-1.33). CONCLUSIONS: The incidence of PE did not increase significantly in ESRD patients from 1992-1997. PE were associated with increased mortality. Peritoneal dialysis patients may have higher risk of PE than hemodialysis patients, and other high-risk groups were identified.

Adult↗

Hospitalizations for bacterial septicemia in patients with end stage renal disease due to diabetes on the renal transplant waiting list.

The incidence and risk factors for hospitalizations for bacterial septicemia, a serious cause of morbidity and mortality in end stage renal disease (ESRD), have been studied separately for patients on chronic dialysis and after renal transplantation, but have not been compared directly. Using data from the USRDS, we studied 11,369 patients with ESRD due to diabetes enrolled on the renal and renal-pancreas transplant waiting list from 1 July 1994-30 June 1997. Cox non-proportional hazards regression models were used to calculate adjusted, time-dependent hazard ratios (HR) for time to hospitalization for bacterial septicemia (ICD9 Code 038.x). In Cox Regression analysis, renal transplantation was independently associated with a shorter time to bacterial septicemia (HR 1.22, 95% confidence interval, 1.05-1.40). In addition, renal transplantation was associated with a higher rate of sepsis due to gram-negative organisms (HR 3.32, 95% CI 2.614.23) and urinary tract infection (10.43, 95% CI 6.72-16.17) compared with patients still on the renal transplant waiting list. The relative risk of sepsis increased with time after renal transplantation. Renal transplantation was associated with a significantly higher risk and different spectrum of bacterial septicemia than maintenance dialysis, and the risk of sepsis did not decrease over time.

Adult↗

Hospitalizations for bacterial pneumonia after renal transplantation in the United States.

PURPOSE: Bacterial pneumonia has been cited as the leading cause of infectious death in renal transplant recipients but has not been studied in a national transplant population. SUBJECT AND METHODS: Retrospective analysis of the incidence, risk factors and mortality of hospitalized bacterial pneumonia (ICD9 Code 481.x486.x) for 33,479 renal transplant recipients in the United States Renal Data System transplanted from 1 July 1994-30 June 1997. RESULTS: Among all transplant recipients, 4.7% were hospitalized for a primary discharge diagnosis of pneumonia in the study period (2.86 episodes per 100 person years). 9.9% had bronchoscopy and 4.8% had open lung biopsy. A specific etiology was not identified in 72.5% of patients. The hospitalization rate for pneumonia and hazard for mortality due to hospitalized pneumonia were both constant over time. In logistic regression analysis, pneumonia prior to transplant (odds ratio 1.73, 95% confidence interval, 1.32-2.26), older recipient age, diabetes, delayed graft function, rejection (occurring at any time after transplant during the time of the study), duration of pre-transplant dialysis, and positive recipient cytomegalovirus serology were associated with pneumonia. In Cox Regression, hospitalization for pneumonia was associated with greater risk of mortality (hazard ratio 1.64, 95% CI, 1.42-1.89). CONCLUSIONS: Renal transplant recipients with a previous history of pneumonia are at increased risk for subsequent pneumonia, which is associated with substantially decreased patient survival. Given the low rate of specific etiologies identified in this study, invasive diagnosis may be underutilized in this population.

Aged↗

Total hip arthroplasty in chronic dialysis patients in the United States.

BACKGROUND: The national incidence of and factors associated with total hip arthroplasty (THA) in chronic dialysis patients has never been reported. METHODS: We therefore performed an historical cohort study of 375,857 chronic dialysis patients listed in the 2000 United States Renal Data System between 1 April 1995 and 31 December 1999 and followed-up until 14 May 2000. Primary outcomes were associations with hospitalizations for a primary discharge code of THA (ICD9 procedure code 81.51x) after initiation of dialysis. RESULTS: Dialysis patients had a cumulative incidence of THA of 35 episodes/10,000 person-years, compared to 5.3/10,000 in the general population. The leading indication for THA was osteoarthritis of the hip and pelvis (58% of cases). However, the strongest risk factor for THA in dialysis patients was end-stage renal disease (ESRD) due to systemic lupus erythematosus (SLE, adjusted rate ratio (ARR), 6.80, 95% CI 4.62-10.03, in whom avascular necrosis of the hip was the most common indication, 68.4%). The database did not include information on use of corticosteroids. Diabetic recipients were significantly less likely to receive THA, as were males, and African Americans. Mortality after THA was 0.25% at thirty days and 30% at three years, not significantly different from the expected mortality of dialysis, adjusted for comorbidity. CONCLUSIONS: The most common indication for THA in dialysis patients is osteoarthritis of the hip, similar to the general population. Patients with SLE are more likely to receive THA which is well tolerated and not associated with increased mortality in this population, perhaps reflecting selection bias due to appropriate screening for this elective procedure.

Aged↗

Body mass index and enrollment on the renal transplant waiting list in the United States.

BACKGROUND: Previous studies of body mass index (BMI) and enrollment on the renal transplant waiting list have not analyzed a national population of chronic dialysis patients. METHODS: 161,265 patients in the United States Renal Data System (USRDS) initiated on end-stage renal disease (ESRD) therapy between 1 April 1995 and 30 June 1997 who had data sufficient to calculate BMI were analyzed in an historical cohort study. Cox Regression analysis was used to model the association of BMI and rates of listing for renal transplantation, censored for death and receipt of renal transplant, and adjusted for demographics, comorbidities in the Medical Evidence Form (2728) and in comparison with patient survival. RESULTS: In univariate analysis, only patients with BMI <21.3 kg/m(2) had a statistically significant lower rate of listing compared to patients with BMI 24.5-28.6 kg/m(2) (6.1 vs. 7.5/100 person years). In Cox Regression analysis, patients with BMI <21.3 kg/m(2) had a 18% lower adjusted rate of listing and a 38% lower rate of survival, and patients with BMI >=24.5-28.7 had an 11% higher adjusted rate of listing and no significant difference in adjusted survival compared with patients with BMI>=28.7 kg/m(2). Caucasian females were disproportionately affected by high BMI. CONCLUSIONS: Among ESRD patients, lower BMI was independently associated with reduced adjusted rates of listing. High BMI affected rates of listing disproportionately in caucasian females.

Aged↗

Hospitalized gastrointestinal bleeding and procedures after renal transplantation in the United States.

The risk of hospitalized gastrointestinal bleeding (GIB) in renal transplant recipients has not been studied in a national renal transplant population. Therefore, 42,906 renal transplant recipients in the United States Renal Data System (USRDS) from 1 July 1994 - 30 June 1998 were analyzed in an historical cohort study of hospitalizations with a primary discharge diagnosis of GIB (ICD9 Code 578.9x) using Cox regression analysis. The 1997 National Hospital Discharge Survey was used to obtain rates of GIB for the general population. Renal transplant recipients had a cumulative incidence of hospitalizations for GIB of 334 events/100,000 person-years. In 1997, compared to the general population, renal transplant recipients had an age-adjusted rate ratio for GIB of 10.69 at one year of follow-up. The strongest risk factors for GIB in Cox regression analysis were graft loss (adjusted hazard ratio, 4.28 (2.84-6.47) and African American recipients who experienced allograft rejection (AHR, 3.04, 95% CI, 1.45-6.37). GIB was associated with increased all-cause mortality (hazard ratio 1.78, 95% CI, 1.39-2.28). GIB is significantly more common in renal transplant recipients than in the general population, and the strongest risk factors are graft loss and African Americans who experience rejection.

Adolescent↗

Arteriovenous fistula use and heart disease in long-term elderly hemodialysis patients: analysis of United States Renal Data System Dialysis Morbidity and Mortality Wave II.

BACKGROUND: There are some concerns that arteriovenous fistula (AVF) use or other dialysis specific factors may exacerbate cardiovascular disease in long-term hemodialysis (HD) patients. METHODS: We performed a historical cohort study of the United States Renal Data System Dialysis Morbidity and Mortality Wave II study, limited to 993 patients who started HD in 1996 with valid information on vascular access and who were primarily eligible for Medicare at the start of the study. We assessed the association between hemodialysis vascular access and heart disease, defined as Medicare Claims for heart failure (HF, International Classification of Diseases (ICD9) code 428.x) and acute coronary syndromes (ACS, ICD9 code 410.x and 411.x). Cox proportional hazards regression (using propensity analysis) was used to model adjusted hazard ratios (AHR) for the association between patients factors and heart disease after dialysis. RESULTS: The rate of HF per 100 person years at risk (PYAR) was 19.6 among AVF users, 25.7 among patients using polytetrafluoroethylene grafts (grafts), and 31.1 among patients using temporary catheters. Corresponding rates of ACS were 8.2 among AVF users, 11.0 among users of grafts, and 12.4 among users of temporary catheters. In Cox Regression analysis, there was no significant association between AVF use and either HF or ACS. This lack of association was consistent across gender, diabetes, race, and age. CONCLUSIONS: We found that AVF use had no significant association with the incidence of HF or ACS. We conclude that use of AVF by 60 days after the start of dialysis is not associated with an increased risk of later non-fatal cardiovascular outcomes in long-term hemodialysis patients.

Aged↗