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Biomedical subjects

Peter G Blake

Publications and source records attributed to Peter G Blake.

At least 19 recordsLinked to original sources
PubMed2003

Effect of awareness of a randomized controlled trial on use of experimental therapy.

CONTEXT: Use of experimental therapies during but outside of randomized controlled trials (RCTs) has not been studied. OBJECTIVE: To determine whether initiation of an RCT leads to increased use of the experimental therapy outside the trial. DESIGN AND SETTING: Data on national apheresis use during 3 Canadian RCTs for multiple sclerosis (1986-1988), thrombotic thrombocytopenic purpura (1982-1988), and myeloma cast nephropathy (1998-2000) were obtained from 19 major medical centers in Canada. The multiple sclerosis and myeloma cast nephropathy trials had data on apheresis use for 3 years prior to and during the trials, which permitted a time-series analysis to determine the impact of the RCTs on the use of apheresis. The ongoing myeloma cast nephropathy trial provided data on the number of patients inside and outside of the RCTs in trial and nontrial centers. Initial and follow-up questionnaires were sent to 24 Canadian physicians in trial and nontrial centers to determine if they had noted an increase in apheresis activity during the trials and, if so, their explanation for it. MAIN OUTCOME MEASURE: Change in number of patients undergoing apheresis for thrombotic thrombocytopenic purpura, multiple sclerosis, and myeloma cast nephropathy prior to and during the respective RCTs compared with all patients undergoing apheresis during the same periods. RESULTS: During all 3 RCTs, there were large increases in use of apheresis. The majority of the increased use of apheresis was outside of the trials: for multiple sclerosis, 30 of 49 patients per year (61% of increase); thrombotic thrombocytopenic purpura, 49 of 56 patients per year (72% of increase); and myeloma cast nephropathy, 60 of 72 patients per year (57% of increase). The myeloma cast nephropathy study noted that this increase occurred in both nontrial and trial centers. Among questionnaire respondents (n = 22; 92% response rate), most physicians noted an increase in apheresis activity during the trials and attributed it to a "jumping-the-gun" phenomenon. CONCLUSIONS: During 3 Canadian RCTs, apheresis increased, but most of the increase occurred outside the trials. This behavior during an RCT, in the absence of clear efficacy, can be termed jumping the gun.

Blood Component Removal↗
PubMed2003

Adequacy of quotidian hemodialysis.

BACKGROUND: Several methods exist to quantitate small-solute clearance by daily hemodialysis (HD) regimens, but these have not been empirically applied or compared. METHODS: In the London Daily/Nocturnal Hemodialysis Study, dosing and adequacy of quotidian HD regimens, both short daily HD (n = 11) and long nocturnal HD (n = 12), were compared with conventional thrice-weekly HD (n = 22) using several models. Urea clearance was computed by percentage of reduction in urea, kinetic modeling (single-pool Kt/V [spKt/V]), Daugirdas rate equation (equilibrated Kt/V [eKt/V]), and Gotch standardized Kt/V (stdKt/V). RESULTS: Nocturnal HD patients maintained a mean single-session spKt/V of 1.64 throughout the study, similar to that of conventional HD patients (1.73), whereas daily HD patients showed a significant decrease in mean single-session spKt/V (0.93) compared with baseline (t(0)) values. Mean weekly spKt/V values increased from t(0) for both quotidian HD groups (9.08 for nocturnal HD, 5.55 for daily HD) and were higher in both quotidian HD groups compared with conventional HD patients. Weekly eKt/V, stdKt/V, and normalized protein equivalent of nitrogen appearance values showed similar trends. Comparison of the 3 different adequacy models showed an increase in weekly HD doses for both quotidian HD regimens compared with conventional HD; however, percentages of increases from t(0) to follow-up differed according to the model used. The calculated efficiency of dose delivery at the 10-month follow-up comparing daily HD with conventional HD was 257 +/- 26 minutes versus 306 +/- 17 stdKt/V unit delivered, respectively, amounting to almost 1 dialysis-hour saved per stdKt/V unit delivered for daily HD. CONCLUSION: These results show that both quotidian HD regimens are more effective than conventional HD in improving weekly urea clearance measured by spKt/V, stdKt/V, and eKt/V.

Adult↗
PubMed2003

Report of the International Society of Nephrology: North American Renal Disaster Response Task Force.

This article comprises a report from the North American Renal Disaster Response Task Force (RDRTF) set up in 2001 by the International Society of Nephrology Acute Renal Failure Commission. The conclusions of the report are (1) given the rarity of renal disasters in the Americas the North American and Latin American RDRTF's should be merged; (2) for the same reason, a single RDRFT Coordination Center for the whole world should be established and it is suggested that this be in Ghent, Belgium; (3) the collaborative group set up in Europe and involving the European RDRTF and Medecins Sans Frontiers be asked to extend their rapid response service to cover acute renal disasters in the Americas south of the United States-Mexico border; (4) the combined RDRTF for the Americas should establish a list of nephrologists, nurses, and technicians who are available to assist in the acute response to renal disasters; (5) the combined RDRTF of the Americas establish an inventory of equipment, machines, and methods for their transport that would be available in the event of a disaster; and (6) the RDRTF of the Americas should undertake a large-scale educational initiative on management of renal disasters.

Advisory Committees↗
PubMed2002

Factors influencing erythropoietin compliance in peritoneal dialysis patients.

BACKGROUND: Peritoneal dialysis patients who manage their own therapy with subcutaneous erythropoietin (EPO) may be at risk for noncompliance. The objectives of this study were to examine the rate of noncompliance and to investigate the factors that are associated with patient noncompliance with the prescribed EPO regimen. METHODS: A multiple-choice questionnaire was mailed to eligible patients, and a review of pharmacy records was conducted for EPO dates of refill. Noncompliance was defined as less than 90% use of the prescribed dose either by pharmacy record review or missed injections on the questionnaire. RESULTS: Of 55 eligible patients, 54 completed the questionnaire. The overall rate of noncompliance was 35%. Patients who were noncompliant were younger (P = 0.005), had fewer comorbidities (P = 0.050), had been on EPO therapy longer (P = 0.011), were more likely to have completed postsecondary education (P = 0.011), and were more likely to admit to missed peritoneal dialysis exchanges (P = 0.011). On multiple regression analysis, the independent predictors of noncompliance, in order of importance, were missing dialysis exchanges, completion of postsecondary education, and younger age. CONCLUSION: These findings suggest that noncompliance with EPO injections is relatively common among peritoneal dialysis patients. The independent predictors of noncompliance were missing dialysis exchanges, completion of postsecondary education, and younger age. Further studies are needed to determine if specific interventions targeting this group of patients can affect compliance.

Age Factors↗
PubMed2002

Economics, focus on pre-dialysis may help stabilize peritoneal dialysis in Canada.

PD use has stabilized somewhat in Canada after five years of relative decline. Fiscal constraints on health care funding in general and fiscal incentives in some provinces to do PD may be contributing to this, and may lead to PD growth in the years ahead. Other factors that may help PD to grow are the proliferation of predialysis clinics with an associated emphasis on the patient's right to make an elective modality choice, new innovations in treatment, ongoing evidence of improving outcomes, and perhaps, more simplicity in prescribing the modality in the post-ADEMEX era.

Canada↗
PubMedDate not supplied

Peritoneal dialysis in Asia: an external perspective.

There are almost 30,000 patients maintained on peritoneal dialysis (PD) in Asia, representing about 8% of all Asian dialysis patients. The largest numbers of PD patients are in Japan and China, but the highest PD penetration is in Hong Kong, Korea, and Singapore. Notable features of PD in Asia include the varying rates of use across the different countries. The reasons for this are reviewed here, with particular emphasis on the significance of whether dialysis providers are predominantly private or public. The excellent rates of both patient and technique survival in the richer Asian countries are also examined and interpreted in the context of recent data showing that Asian patients living in North America have generally superior survival on dialysis and better compliance with PD than their Caucasian counterparts. It is concluded that the healthier baseline health status in South East Asian patients, in particular, contributes to their impressive outcomes. The approach to both clearance and ultrafiltration is less aggressive in Asian countries than in the West. Studies looking at the relationship between clearance and clinical outcome in Asia are reviewed and it is concluded that the benefits of higher clearances have been harder to show than in North America because of the relatively better outcomes of the patients. The concern about sclerosing encapsulating peritonitis in Japan particularly is emphasized. The Hong Kong model of dialysis delivery with its high use of PD and the arguments for and against it are also reviewed.

Asia↗
PubMedDate not supplied

Changes in peritoneal dialysis practices in Canada 1996-1999.

OBJECTIVE: Over the past decade, clinical studies and clinical practice guidelines have suggested the use of higher small solute clearance targets for patients on peritoneal dialysis (PD). This study asks whether these recommendations have translated into changes in clinical prescription of PD. STUDY DESIGN: Data were collected annually from 1996 to 1999 on all prevalent dialysis patients in 24 Canadian centers, accounting for approximately 40% of the Canadian chronic dialysis population. Approximately a third of these patients were on PD. Full details of each patient's prescription were recorded, with particular attention to dwell volumes and frequency of exchanges for continuous ambulatory PD (CAPD) and to total treatment volumes and day dwells for automated PD (APD). The most recent Kt/V and creatinine clearance values available were recorded for each patient and the overall results for each year were compared to present treatment recommendations. SETTING: 24 university- and community-based hospitals. RESULTS: From 1996 to 1999, the use of APD, relative to CAPD, grew from 14% to 28% of all PD patients. Among CAPD patients, the proportion using dwell volumes greater than 2 L rose from 14% to 32%, and the proportion doing more than 4 dwells per day rose from 16% to 28%. The mean daily volume of prescribed fluid for CAPD patients increased from 8.3 to 9.1 L. As a result, the proportion of patients achieving a weekly Kt/V above 2.0 rose from 54% to 72%, and those receiving a Kt/V less than 1.7 fell from 22% to 10%. For creatinine clearance, those exceeding 60 L per week rose from 63% to 73%. For APD, the mean treatment volume rose from 11.8 L in 1996 to plateau at about 13.4 L in 1998 and 1999. However, the proportion of patients receiving more than 1 day dwell grew from 31% in 1998 to 40% in 1999, and the proportion that were "day dry" fell from 25% to 17%. For APD, the proportion of patients with a Kt/V above 2.0 rose from 67% to 77%, and with a creatinine clearance above 60 L, from 62% to 70%. The proportion with no recent clearance value recorded fell during the course of the study, from 45% to 27%. CONCLUSION: There was a marked change in PD prescription practices in Canada during the second half of the 1990s. This occurred in response to clinical studies and publication of guidelines. There is room for further improvement, especially with respect to the proportion of patients that did not have regular clearance measurements made.

Canada↗
PubMedDate not supplied

Peritoneal dialysis in Ontario: a natural experiment in physician reimbursement methodology.

BACKGROUND: The factors that determine dialysis modality selection and distribution are not well understood. Physician reimbursement incentives have been suggested to play an important role. Under the fee-for-service system in Ontario that existed prior to July 1998, nephrologists were paid about sevenfold more for a hemodialysis (HD) patient than for a patient on peritoneal dialysis (PD). However, since then, nephrologists have been reimbursed via a modality-independent capitation fee, whereby payment for any form of dialysis is the same. This was expected to markedly increase the use of PD. METHODS: When the capitation fee was introduced in 1998, a survey questionnaire of all Ontario nephrologists was done and repeated 3 years later (response rate 62.5%). Changes in dialysis modality incidence and prevalence rates in Ontario and in the rest of Canada were examined. RESULTS: On a scale of 1 to 7, nephrologists were convinced that the capitation fee was a good thing (mean rating 6.07); 75% said they had been seeing patients at every dialysis under the old system, compared to 41% now. Of significance, the proportion of prevalent patients on PD in Ontario declined from 27.3% in 1997 to 19.7% in 2000, increasing to 22.6% in 2002. Similarly, the incident PD rate seems to have stabilized, while the use of nonhospital-based HD has increased. CONCLUSIONS: Following the introduction of the capitation fee, PD use in Ontario continued to decline for 2 years, and then began to increase. In the rest of Canada, there are continuing declines in PD use. This is consistent with the hypothesis that the new incentives caused by the altered physician reimbursement are acting in a subtle way to increase PD and non-hospital-based HD. A longer period of observation may be required to assess the complete effect.

Capitation Fee↗
PubMedDate not supplied

Cycling forward.

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Automation↗