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Biomedical subjects

F K Port

Publications and source records attributed to F K Port.

At least 91 records · Page 5Linked to original sources
PubMed1995

Differences in the patterns of age-specific black/white comparisons between end-stage renal disease attributed and not attributed to diabetes.

To assess differences in the patterns of age-specific black/white comparisons between end-stage renal disease (ESRD) attributed to diabetes (ESRD-DM) and not attributed to diabetes (ESRD-NON-DM), data for subjects 20 to 79 years of age reported by the US Renal Data System as incident cases of ESRD during 1988 to 1991 were analyzed. While the black to white incidence rate ratio (B/W RR) for ESRD-NON-DM peaked in patients before the age of 40 years, the most striking B/W RRs for ESRD-DM were observed in patients older than 40 years. This study also explored evidence supporting the hypothesis that an increased risk of premature death attributed to cardiovascular disease (CVD death) in black patients, alone or in combination with black/white differences in prevalence of diabetes, influences the pattern of age-specific black/white ESRD-DM comparisons. By using estimates of the diabetic population as denominators for the rates, the incidence or ESRD-DM remained much higher in black patients than in white patients for those aged 45 years or above. However, the incidence of ESRD-DM for patients aged below 45 years was found to be significantly (P < 0.05) lower (B/W RR = 0.6) for black male diabetic patients and slightly, yet significantly, higher (P < 0.05; B/W RR = 1.1) for black female diabetic patients than for their white counterparts. Therefore, prevalence of diabetes could not fully explain the pattern of age-specific B/W RR for ESRD-DM.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Inferior outcome of two-haplotype matched renal transplants in blacks: role of early rejection.

Acute rejection in the early post-transplant period is a major determinant of long-term outcome. A cohort analysis was performed to evaluate the race-specific incidence rates of early acute rejection episodes (AR) and delayed graft function (DGF) in Americans of African (blacks) and European (whites) descent (N = 2565) who received a 2-HM living-related donor (LRD) first kidney transplant between 1984 and 1992. After adjusting for center and recipient characteristics, blacks had a higher incidence of AR during the initial transplant hospitalization (blacks 13.2% vs. whites 7.4%, OR = 1.64, P = 0.02). DGF also occurred more frequently in blacks (unadjusted OR = 1.58, P = 0.07). Blacks with AR had significantly worse Cox-adjusted five year graft survival than similarly affected whites (blacks 50% vs. whites 76%, P < 0.01). We conclude that failure to take immunosuppressive medications cannot be implicated as a cause of the higher incidence of AR during the initial transplant hospitalization in black kidney transplant recipients. The excess risk of AR in blacks may reflect previously reported intrinsic differences in immune responsiveness and/or pharmacokinetics of immunosuppressive agents. The profound deleterious effect of AR appears to be largely responsible for the accelerated rate of late graft loss in African Americans.

Adult↗
PubMed1995

Hospitalization among United States dialysis patients: hemodialysis versus peritoneal dialysis.

Measurements of hospitalization in the dialysis population are important because they provide insight into the morbidity and the cost of treatment among dialysis patients. Prior comparisons of hospitalization for different dialysis modalities have had conflicting results. This study was designed to compare hospitalization for patients treated with peritoneal dialysis (PD) versus hemodialysis (HD) using the data from the U.S. Renal Data System 1993 Annual Data Report. The study population included all Medicare dialysis patients prevalent on January 1, 1988 through 1990. Patients were monitored to transplantation, death, or end of the calendar year for a total of 189,654 patient years. Hospital admission rates were computed from the total number of hospital admissions during the year divided by the total number of patient years at risk. Patients were classified by treatment modality (PD, HD), cause of ESRD (diabetes as a cause of ESRD versus all other causes), age (0 to 19, 20 to 44, 45 to 65, +65), and race (black, white). Rate ratios (RR:PD/HD) for hospital admissions per year at risk were estimated, while adjusting for the other factors with Poison regression. On average, hospital admission rates per patient year at risk for dialysis patients treated with PD were 14% higher than for those treated with HD (RR = 1.14; 95% confidence interval (Cl), 1.13 to 1.15) when adjusting for race, age, gender, and cause of ESRD. The excess in the overall adjusted admission rates in PD patients compared with HD patients was higher for black than for white patients (RR:PD/HD = 1.22 versus RR = 1.11; 95% Cl, 1.10 to 1.13).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

A comparison of mortality between patients treated with hemodialysis and peritoneal dialysis.

Patients with ESRD treated with dialysis have a high mortality rate. Controversy exists as to whether this high mortality rate is affected by modality choice. The purpose of this epidemiologic study was to compare mortality in prevalent hemodialysis-treated (HD) and peritoneal dialysis-treated (PD) patients in a large national sample, adjusting for demographic characteristics. Data were obtained from the U.S. Renal Data System for patients prevalent on January 1 of the years 1987, 1988, and 1989, each with 1 yr of follow-up. Patients were censored at transplantation. Death rates per 100 patient years were compared between HD and PD, adjusting for age, race, gender, cause of ESRD (diabetes versus nondiabetes) and < 1 yr or > 1 yr of prior ESRD, by the use of Poisson regression. There were 42,372 deaths occurring over 170,700 patient years at risk. On average, prevalent patients treated with PD had a 19% higher adjusted mortality risk (relative risk (RR) = 1.19; P < 0.001) than did those treated with HD. This risk was found to be insignificant (P > 0.05) and small for ages < 55 and increasingly large and significant for ages > 55 yr. It was accentuated in diabetics (RR = 1.38; P < 0.001) but was also present in nondiabetics (RR = 1.11; P < 0.001). Although present in both males and females, this risk was accentuated in females (RR = 1.30 versus 1.11; both P < 0.001). In this national study of prevalent U.S. dialysis patients, treatment assignment to PD was associated with a 19% higher all-cause mortality rate than HD.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1995

A comparison of cause of death between patients treated with hemodialysis and peritoneal dialysis.

Mortality rates associated with peritoneal dialysis (PD) have been found to be higher than those associated with hemodialysis (HD) among prevalent U.S. patients over the age of 55 in the preceding study. Given the substantial technical differences between PD and HD, causes of death might also be expected to differ between these dialytic modalities. In order to help elucidate the relative contributions of these technical differences and to further the understanding of the excess mortality observed among PD-treated dialysis patients, this epidemiologic study compared cause of death in prevalent HD- and PD-treated patients in a large national sample, adjusting for demographic characteristics. Data for patients prevalent on January 1 of the years 1987, 1988, and 1989, each with 1 yr of follow-up, were obtained from the U.S. Renal Data System. Patients were censored at transplantation. Death rates per 100 patient years for seven cause-of-death categories were compared between HD and PD, adjusting for age, race, gender, cause of ESRD (diabetes versus nondiabetes), and < 1 yr or > 1 yr of prior ESRD, by use of the Poisson regression. There were 42,372 deaths occurring over 170,700 patient years at risk. There was a significantly increased mortality risk for PD compared with HD for all cause-of-death categories, except malignancy, for which there was a higher mortality risk for HD. The excess all-cause mortality observed in PD-treated patients can be accounted for, in decreasing order, by infection (35%), acute myocardial infarction (24%), other cardiac causes (16%), cerebrovascular disease (8%), withdrawal (8%), and malignancy (-6%).(ABSTRACT TRUNCATED AT 250 WORDS)

Cause of Death↗
PubMed1995

End-stage renal disease: magnitude of the problem, prognosis of future trends and possible solutions.

The incidence rate per million population of treated end-stage renal disease (ESRD) has been increasing at similar rates in most countries that record counts of new ESRD patients per year. Data from the United States Renal Data System (USRDS) suggest an exponential growth for both incidence rates and prevalence rates. Doubling of the number of new patients per year occurred over a recent 8.5 year period, and this interval was even shorter for older patients, Asians, Native Americans and for patients with diabetes or hypertension as cause of ESRD. Reasons for this growth in incidence include greater acceptance to therapy of older and sicker patients, reduced mortality from other conditions and possibly more kidney disease. A recent reduction in mortality rates for ESRD patients in the US has additionally influenced the growth in prevalence. In view of these striking recent trends a prognosis for the next decade is discussed. As major possible solutions prevention efforts for renal disease and for the progression of renal disease are proposed, as are means to enhance renal organ donation.

Forecasting↗
PubMed1994

The impact of HLA mismatches on the survival of first cadaveric kidney transplants.

BACKGROUND: The benefits of HLA-A, B, and DR matching of cadaveric kidney grafts and recipients remain controversial when viewed from the perspective of social equity and graft survival. METHODS: We estimated graft survival using proportional-hazards techniques, adjusting for patient and donor characteristics, for a series of 30,564 Medicare patients receiving a first cadaveric kidney transplant between 1984 and 1990. The effects of minimal achievable HLA mismatches and maximal matching on graft survival were estimated by simulated allocation of a sample of organs to a sample of 20,000 candidates for transplantation. RESULTS: The adjusted one-year graft survival was 84.3 percent for grafts with no mismatches and 77.0 percent for grafts with four mismatches. National rationing of donor organs to achieve minimal mismatching and maximal matching could potentially decrease the average number of HLA mismatches from 3.6 to 1.2, with a corresponding increase in the number of matches. As a consequence, projected five-year graft survival could potentially increase from 58.5 percent to 62.9 percent. This would be associated with a decrease in the proportion of kidneys allocated to black recipients from 22.2 to 15.0 percent. CONCLUSIONS: Under ideal circumstances, a policy of maximal matching of cadaveric renal transplants would increase five-year graft survival by a comparatively small 4.4 percentage points, but the actual benefit is likely to be smaller.

Adolescent↗
PubMed1994

Effect of race on access to recombinant human erythropoietin in long-term hemodialysis patients.

OBJECTIVE: To quantify access to recombinant human erythropoietin (EPO) among patients with dialysis-dependent end-stage renal disease (ESRD). DESIGN: National random sample of hemodialysis patients from a random sample of dialysis units, using data abstracted from patients' medical records. SETTING: All US hemodialysis units. PARTICIPANTS: A total of 4024 Medicare-entitled in-center hemodialysis patients. MAIN OUTCOME MEASURES: The relative odds that black patients received EPO (compared with white patients). RESULTS: There was no evidence in this national study that black hemodialysis patients were more or less likely to receive EPO than white patients (P = .74). CONCLUSIONS: Three years after Food and Drug Administration approval and Medicare coverage of EPO, there was no evidence of racial disparity in access to EPO among Medicare patients with ESRD who were receiving long-term hemodialysis. However, there was evidence of greater need for EPO among black patients.

Black People↗
PubMed1994

Analysis of the association of dialyzer reuse practices and patient outcomes.

This historic prospective study assessed the relationship between dialyzer reuse practices and hemodialysis patient mortality through 1 year of follow-up. Medicare patient demographic and survival data were combined with dialyzer reuse data from the Centers for Disease Control and Prevention's annual survey of dialysis-related diseases. Data were analyzed for the US Medicare hemodialysis population of never transplanted patients prevalent on January 1, 1989, and January 1, 1990, who were treated in freestanding dialysis units that used primarily conventional (not high-flux) dialyzers. Time to mortality, or transplant, and other censoring on December 31st of each year was regressed with proportional hazards models on patient, dialysis unit, and reuse measures. Age-, race-, and diagnosis-standardized mortality ratios for dialysis units were also regressed with weighted least squares techniques against dialysis unit and reuse measures. The results showed that patients treated in dialysis units that disinfected dialyzers with a peracetic acid, hydrogen peroxide, acetic acid mixture, or glutaraldehyde experienced higher mortality than patients treated in units that used formalin or in units that did not reuse dialyzers. The relative risk of mortality, compared with patients treated in nonreuse dialysis units, was 1.17 (P = 0.010) for glutaraldehyde and 1.13 (P < 0.001) for the peracetic acid mixture. The relative risk for formalin compared with the reference group of nonreuse was 1.06 (P = 0.088). With adjustment for several patient and dialysis unit characteristics, dialyzer reuse with certain germicides was associated with a significantly elevated mortality risk. This elevated risk, the etiology of which is currently not known, may represent a large number of potentially avoidable deaths per year. Only a large, nationally based analysis of this type has sufficient sample size to detect mortality risks such as these.

Dialysis↗
PubMed1994

Comparative mortality risks of chronic dialysis and cadaveric transplantation in black end-stage renal disease patients.

In view of the relatively low mortality risk on dialysis and the high risk of allograft loss among black compared with white end-stage renal disease (ESRD) patients, we studied the relative mortality risks of all black renal transplant candidates in Michigan from 1984 to 1989. There were 770 black ESRD patients followed from wait-listing for cadaveric (CAD) kidney transplantation until the time of transplantation, death, or December 31, 1989. The time on dialysis prior to wait-listing exceeded 1 year in 24% of these patients. Black diabetic patients on the waiting list have more than twofold relative mortality risk (RR) compared with nondiabetic individuals (RR = 2.73, P < 0.001) while the RR by diabetes status among CAD transplant recipients was small. Overall, CAD transplantation was associated with elevated risk of mortality in the first month posttransplantation (RR = 3.39, P < 0.03). Cadaveric donor transplant and wait-listed dialysis patients have equal death rates 112 days after transplantation. Thereafter, death rates were lower for transplant recipients compared with transplant candidates on dialysis. One year after transplantation, CAD transplant recipients on the average have approximately half the risk of death compared with dialysis patients who remain on the waiting list (RR = 0.49, P < 0.03). The cumulative survival probabilities are superior in transplant recipients just beyond 1 year after transplantation. Therefore, CAD transplantation in black ESRD patients is associated with a high risk of mortality in the early period after transplantation. Beyond 1 year, black transplant recipients have a substantial survival advantage over corresponding dialysis patients on the waiting list.

Adolescent↗
PubMed1994

The joint effects of race and age on the risk of end-stage renal disease attributed to hypertension.

To describe the joint effects of race and age on the risk of end-stage renal disease (ESRD) attributed to hypertension (ESRD-HT), we analyzed data for white and black adults, 20 to 84 years of age, reported by the United States Renal Data System during the period 1987 to 1990. The risk of ESRD-HT increased substantially with age for both blacks and whites; however, at each age, the risk was greater for blacks. A more in-depth description of the combination of effects involving race and age on ESRD-HT incidence was provided by two models of joint effects, one additive and the other multiplicative. Both models used the 20- to 24-year age group as the referent. Under the additive model the risk of ESRD-HT in blacks attributable to the joint effects between race and age increased continuously from younger to older groups. This indicates that although ESRD-HT risk increases with age for both blacks and whites, the increase for blacks is greater than expected if the effects of race were independent of the effects of age. However, the multiplicative model indicated that the proportional increase with age in ESRD-HT risk among blacks, as compared with whites, was more striking for younger ages (< or = 50 years among women and < or = 40 years among men), and especially so for men. This suggests a more accelerated course of hypertension toward ESRD for blacks (especially younger men) than for whites. A conceptual model to explain these patterns of race-age joint effects is proposed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Hemodialysis therapy in the United States: what is the dose and does it matter?

There is an ongoing discussion in the renal community about how to monitor the treatment of hemodialysis patients in the United States. Comparison of the US patient experience to that of other countries with populations of similar health status is one way to assess treatment. Another technique involves examining the level of dialysis therapy US patients receive. This paper reviews recent studies which found that the United States has higher mortality than both Japan and Europe and provides additional information as to why those comparisons might be underestimating the mortality differences. We also examine the data on the level of dialysis US patients receive, both as a prescription and as delivered care. We conclude that US patients receive less hemodialysis therapy than their European and Japanese counterparts, and that in general US patients are not receiving the level of dialysis they were prescribed. These factors are correlated with an increased mortality among US hemodialysis patients.

Europe↗
PubMed1994

Socioeconomic status and end-stage renal disease in the United States.

The incidence of treated end-stage renal disease (ESRD) varies markedly according to age, race, sex, and geographic characteristics of the population. We asked whether some of the variability in the incidence of treated ESRD (t-ESRD) was associated with differences in socioeconomic status and whether socioeconomic status could explain some of the effects of race on t-ESRD incidence. Demographic characteristics of incident cases of t-ESRD from the years 1983 to 1988 were obtained from the U.S. Renal Data System, which registers most treated cases of ESRD. The average race specific, per capita income of the county of residence, as determined from the Bureau of Health Professions Area Resource File, was used as a surrogate measure of socioeconomic status. the incidence of t-ESRD for individuals < 60 years of age was modeled as a log-linear function of socioeconomic and demographic factors, including age, sex, the urban fraction of the county of residence, and the census geographic region. For both Whites and Blacks, the incidence of t-ESRD was higher for males and older age groups, as expected. In general, the incidence of t-ESRD was inversely related to income level. For Whites, the relative risk was 1.21 for income of $0 to 10.000, 1.11 for $10,000 to 15,000, 1.00 for $15,000 to 20,000 (reference), 0.89 for $20,000 to 25,000, and 0.77 for income > $25,000. For Blacks, the relative risk was 1.10 for income of $0 to 10,000, 1.20 for $10,000 to 15,000, 1.00 for $15,000 to 20,000 (reference), 0.81 for $20,000 to 25,000, and 0.69 for income > $25,000.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Continuous ambulatory peritoneal dialysis and hemodialysis: comparison of patient mortality with adjustment for comorbid conditions.

A historical prospective national sample of 1,725 diabetic and 2,411 non-diabetic Medicare end-stage renal disease (ESRD) patients incident from 1986 to 1987 was analyzed for the mortality of patients selected to receive continuous ambulatory peritoneal dialysis (CAPD) or hemodialysis (HD) with adjustment for patient characteristics, including the presence of comorbid conditions at onset of ESRD. Cox proportional hazards analyses were used to compare the mortality of CAPD and HD patients. Patients were followed from 30 days following onset of ESRD until two to four years post-onset. No statistically significant difference in relative mortality risk (RR) was found among non-diabetic patients selected for CAPD compared to HD (RR = 0.84 for CAPD versus HD, P = 0.25), while evidence of higher adjusted mortality for CAPD compared to HD was found among diabetic patients (RR = 1.26, P = 0.03). Mortality analyses adjusted for pre-treatment risk factors suggest that CAPD and HD provide incident non-diabetic ESRD patients with similar expected survival outcomes. Evidence that increased mortality was associated with CAPD among diabetic patients, particularly among elderly patients, suggests the need for further controlled studies of mortality among CAPD patients with diabetes.

Aged↗
PubMed1994

Potential pitfalls in interpreting maps of stabilized rates.

There have been many advances in the mapping of disease mortality and morbidity rates in recent years. An increasingly common approach is to calculate "stabilized" rates for individual geographic areas by incorporating information from the entire set of data. One such method, adopted by the Environmental Protection Agency [corrected] for its mortality maps, is described and applied to national end-stage renal disease data. Some possible difficulties in interpretation are noted, resulting from: (1) insufficient shrinkage, (2) highly skewed rate distributions, (3) different denominator distributions, and (4) variations in population density.

Aged↗
PubMed1994

The association of diabetic status, age, and race to withdrawal from dialysis.

Higher rates of withdrawal from dialysis have been shown among young diabetic patients. This study examined the hypothesis that diabetic status has a joint effect with age as the result of an age-related increase in co-morbid conditions among nondiabetic ESRD patients. Using data collected during the 1980s by the Michigan Kidney Registry, the experience of 4,753 white and 2,988 black Michigan dialysis patients (13,863 patient years) is analyzed. During follow-up, 364 white and 80 black patients withdrew from dialysis. By use of a Cox analysis, adjusted rates of withdrawal were shown to be higher among white than black patients (rate ratio (RR) = 3.34; P < 0.001), without significant differences by diabetic status. Rates increased with age (RR = 7.9 for 80+ versus 20 to 35 yr; P < 0.001), without significantly different patterns by race. Adjusted withdrawal rates among diabetics were 2.3 times that of nondiabetics overall (P < 0.001), with a statistically significant joint effect with age, the RR being highest among young patients. Among white patients, nondiabetics using continuous ambulatory peritoneal dialysis had a lower relative withdrawal rate than those using hemodialysis (RR = 0.73; P = 0.07), whereas diabetics using continuous ambulatory peritoneal dialysis showed slightly higher although statistically insignificant rates than their counterparts using hemodialysis (RR = 1.21; P = 0.50). Between 1980 and 1989, withdrawal rates for white patients aged 20 to 34 yr tended to decrease by 20% per year (P = 0.05), whereas they increased by 11% per year for patients aged 50 to 69 yr (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗