Trends in mortality rates on hemodialysis in Canada, 1981–1997. Significant improvements in hemodialysis (HD) have occurred during recent years. Few previous studies have explicitly examined trends ...in patient outcomes over time. In order to evaluate whether improvements in HD have resulted in decreased mortality, we analyzed trends in mortality rates among the 28,700 patients who initiated HD in Canada during the 1981–1997 period. Mortality rate ratios (RR) were estimated using Poisson regression, and adjusted simultaneously for age, race, gender, primary renal diagnosis and follow-up time. Adjusted mortality rates decreased significantly by calendar period, with RR = 0.90 (95% CI: 0.83–0.96) for 1990–93 and RR = 0.74 (0.69–0.80) for 1994–97, relative to 1981–85 (reference; RR = 1). The decrease was concentrated in the first two years of follow-up. Among causes of death, mortality due to cardiovascular disease showed the sharpest decline. Among subgroups defined by age and diabetes status, mortality improvement was strongest among diabetics age <65 years and weakest among non-diabetics age <65 years. The observed decreases in HD mortality could be due to enhancements in dialysis technology, including improvements in dialysis machines, water purification systems, dialysate composition, and biocompatibility of dialyzer membranes. Key roles were likely played by increased attention to HD adequacy on the part of clinicians, improved nutrition, better management of comorbid conditions, and increased erythropoietin utilization. Detailed data on practice patterns are required in order that the degree of association between trends in dialysis methodology and mortality may be quantitatively evaluated.
Projecting renal replacement therapy–specific end-stage renal disease prevalence using registry data. End-stage renal disease incidence and prevalence are increasing in many countries worldwide. ...Projections of ESRD prevalence are useful for forecasting future resource requirements, and organ failure registry databases are valuable for the development of appropriate projection models. We outline one method of generating renal replacement therapy (RRT)–specific ESRD prevalence projections based on data obtained from the Canadian Organ Replacement Register (CORR). To illustrate the methods, we present national RRT-specific prevalence projections for Canada to the year 2005. Continued large increases in ESRD incidence and prevalence are projected, particularly among diabetics. As of December 31, 1996, there were 17,807 patients receiving RRT in Canada. This number is projected to climb to 32,952 by the end of 2005, for a relative increase of 85% (average relative increase of 5.8% per year). Registry data are a useful basis for future health care planning.
The descriptive analyses presented in this chapter provide a brief overview of transplant activity in Canada. While Canada's cadaveric organ donation rate has remained static, between 13-14 per ...million population, transplant rates increased from 1992-2001. This growth was due to more organs being retrieved per cadaveric donor and increased rates of living donor transplants for kidney, most notably, but also liver. The steady climb of the transplant waiting list continued to outstrip the number of patients transplanted on an annual basis. In 2002, 237 people died will waiting for an organ transplant. Canada is a net importer of organs from the US, particularly hearts and lungs. Heart transplantation activity has varied least of all organ transplant types from 1992-2001, reflecting in large part the stagnant cadaveric donation rate and the fact that fewer than 40% of hearts were retrieved and transplanted from the available cadaveric donors. Liver, lung, most notably double lung, and pancreas/kidney-pancreas transplant activity all grew significantly from 1992-2001. Accumulated expertise in the surgical realm combined with improved donor management and organ preservation techniques have facilitated this growth. Patient and graft survival continue to increase in Canada both for patients who are very ill at the time of their transplant, and those not as ill. Future growth areas for transplantation in Canada will likely be in the area of living kidney and liver donation, continued kidney-pancreas transplantation and islet cell transplantation. Without significant improvements in cadaveric organ donation rates in Canada, exploration of expanded donation criteria like non-heartbeating donors as well as continued improvements in donor management for the purposes of increased organ retrieval, the transplantation rates for hearts, livers, and lungs are not expected to increase, and the gap between the number of patients waiting for a transplant and the number of patients transplanted will widen.
The number of patients initiating treatment for end-stage renal disease (ESRD) has increased dramatically in Canada and other countries. To assist healthcare planners, the prevalence of ESRD in ...Canada has been projected to the year 2000 using a Markov modelling technique. Significant increases in ESRD are expected in Canada during the next decade, particularly among the elderly and diabetic populationsestimated increases in prevalence rates of ESRD between 1992 and the year 2000 were 78% and 154% for non diabetic and diabetic populations respectively. These expected increases did not differ significantly between the treatment groups, except among patients with diabetes, in whom projected increases in the prevalence of functioning transplant was smaller than for hemodialysis or peritoneal dialysis. Because the current Canadian prevalence rates are lower than those of some other countries, such as the United States and Japan, these expected trends in prevalence appear reasonable, and illustrate the growing healthcare needs of the ESRD population in Canada during the next decade. ASAIO Journal 1995; 41:230-233.
The authors describe and empirically demonstrate a form of bias that results from deriving subjects for clinical studies from available patients currently being followed in specific disease clinics ...instead of inception cohorts (patients enrolled at a uniform and early point in their disease). They label this effect "clinic patient bias." It is a variation of prevalence-incidence (Neyman) bias in that it also results from the time gap between the onset of a specific characteristic (a risk factor, exposure or disease) and enrollment in the study, causing selective exclusion of fatal or short episodes, or mild or silent cases. Clinic patient bias may distort an estimate of relative risk in either direction. The empirical example is derived from a study of risk factors for developing complications such as peritonitis among end-stage renal disease patients treated with continuous ambulatory peritoneal dialysis (CAPD). The use of available clinic patients rather than an inception cohort (patients newly beginning CAPD) resulted in the demonstration of false apparent risk relationships for two variables: the calendar date when patients began CAPD (with those enrolled at an earlier time appearing to be at lower risk), and serum albumin level at the start of CAPD (with those having lower albumin levels appearing to be at higher risk). This example demonstrates one of the potential hazards of using active or available clinic patients as a source of subjects for clinical studies.
Vestibular toxicity is known to occur from gentamicin. Over a five-year period seven patients with severe and prolonged ataxia from gentamicin vestibular toxicity were seen. Two of these patients ...were not in renal failure. Case reports of five of these are presented. The possible explanations for prolonged disability are discussed.
Continuous ambulatory peritoneal dialysis (CAPD) has been initiated on 51 patients: 27 females (mean age -- 43.9 years) and 24 males (mean age -- 46.4 years). This group has been observed for a total ...of 1420 patient weeks of treatment (27.3 patient years). Thirty-six episodes of peritonitis have been noted among 19 patients. The overall incidence was one episode per 39.4 patient weeks. Recurrent episodes of peritonitis resulted in discontinuation of CAPD in five (9.8%) of the patients. Three (5.9%) of the patients were unable to continue with CAPD because of its inability to control extracellular fluid balance. In the patients who transferred from intermittent peritoneal dialysis to CAPD, there was a 4.5 mg/dl drop in serum creatinine and a 34 mg/dl drop in mean BUN values. There was a rise of approximately 2 gm in the hemoglobin levels of this group of patients. If the problem of peritonitis can be solved, CAPD will become the dialytic treatment of choice for the majority of patients with end-stage renal disease.
This study revealed the following. Malnutrition was frequent (41.6%) in patients on CAPD for less than three months and was present in 18.1% of patients on CAPD for longer than 3 months. Fifty ...percent of these malnourished patients returned to normal on conventional nutritional management within 2 to 6 months, but 10% remained malnourished throughout the study period. There was increased mortality among malnourished patients, but we were unable to demonstrate that the state of nutrition was an independent risk factor, because of the increased prevalence of other co-morbid risk factors known to influence survival and because of the limitation of a small sample size. The influence, if any, of nutritional state as an independent risk factor on the survival of CAPD patients should be answered, because malnutrition is potentially reversible with aggressive nutritional interventions, such as enteral, parenteral, or intraperitoneal supplementation.
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