Need for a registry of living kidney donor outcomes.
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Kidney Transplantation↗
Biomedical subjects
Amit X Garg
Publications and source records attributed to Amit X Garg.
Underrepresentation of renal disease in randomized controlled trials of cardiovascular disease.
CONTEXT: Patients with renal disease are at high risk for cardiovascular mortality. Determining which interventions best offset this risk remains a health priority. OBJECTIVE: To quantify the representation of patients with renal disease in randomized controlled trials for interventions proven efficacious for cardiovascular disease. DATA SOURCES: We searched MEDLINE for trials published from 1985 through 2005 in 11 major medical and subspecialty journals. STUDY SELECTION: Randomized controlled trials for chronic congestive heart failure and acute myocardial infarction of treatments that are currently listed as class I or II recommendations in the current American College of Cardiology/American Heart Association guidelines were included. DATA EXTRACTION: Two reviewers independently abstracted data on study and patient characteristics, renal measurements, outcomes, and prognostic features. DATA SYNTHESIS: A total of 153 trials were reviewed. Patients with renal disease were reported as excluded in 86 (56%) trials. Patients with renal disease were more likely to be excluded from trials that were multicenter; of moderate enrollment size; North American; that tested renin-angiotensin-aldosterone system antagonists and anticoagulants; and that tested chronic congestive heart failure. Only 8 (5%) original articles reported the proportion of enrolled patients with renal disease, and only 15 (10%) reported mean baseline renal function. While 81 (53%) trials performed subgroup analyses of some baseline characteristic in the original article, only 4 (3%) subgroup analyses of treatment stratified by renal disease were performed. CONCLUSION: Major cardiovascular disease trials frequently exclude patients with renal disease and do not provide adequate information on the renal function of enrollees or the effect of interventions on patients with renal disease.
Cardiovascular Diseases↗
Meta-analysis: risk for hypertension in living kidney donors.
BACKGROUND: The risk for hypertension after kidney donation remains uncertain. PURPOSE: To see whether normotensive adults who donate a kidney develop higher blood pressure and risk for hypertension compared with nondonor adults acting as control participants. DATA SOURCES: MEDLINE, EMBASE, and Science Citation Index were searched from 1966 until November 2005 for articles published in any language. Reference lists of pertinent articles were also reviewed. STUDY SELECTION: The authors selected studies involving 10 or more healthy normotensive adults who donated a kidney and in whom blood pressure was assessed at least 1 year later. DATA EXTRACTION: Two reviewers independently abstracted data on study and donor characteristics, blood pressure measurements, outcomes, and prognostic features. Comparison data were abstracted from donor studies with control participants. Thirty primary authors provided additional data. DATA SYNTHESIS: Forty-eight studies from 28 countries followed a total of 5145 donors. Before surgery, the average age of donors was 41 years, the average systolic blood pressure was 121 mm Hg, and the average diastolic blood pressure was 77 mm Hg for all studies. In controlled studies in which the average follow-up was at least 5 years after donation (range, 6 to 13 years), blood pressure was 5 mm Hg higher in donors than in control participants (the weighted mean for systolic blood pressure using 4 studies involving 157 donors and 128 control participants was 6 mm Hg [95% CI, 2 to 11 mm Hg], and the weighted mean for diastolic blood pressure using 5 studies involving 196 donors and 161 control participants was 4 mm Hg [CI, 1 to 7 mm Hg]). There was statistical heterogeneity among the 6 controlled studies that assessed hypertension; an increase in risk was noted in 1 study (relative risk, 1.9 [CI, 1.1 to 3.5]). LIMITATIONS: Most studies were retrospective and did not include control groups that were assembled and followed along with donors. Approximately one third of the donors had incomplete follow-up information. CONCLUSIONS: On the basis of the limited studies conducted to date, kidney donors may have a 5-mm Hg increase in blood pressure within 5 to 10 years after donation over that anticipated with normal aging. Future controlled, prospective studies with long periods of follow-up will better delineate safety and identify donors at lowest risk for long-term morbidity.
Adult↗
Chronic kidney disease and mortality risk: a systematic review.
Current guidelines identify people with chronic kidney disease (CKD) as being at high risk for cardiovascular and all-cause mortality. Because as many as 19 million Americans may have CKD, a comprehensive summary of this risk would be potentially useful for planning public health policy. A systematic review of the association between non-dialysis-dependent CKD and the risk for all-cause and cardiovascular mortality was conducted. Patient- and study-related characteristics that influenced the magnitude of these associations also were investigated. MEDLINE and EMBASE databases were searched, and reference lists through December 2004 were consulted. Authors of 10 primary studies provided additional data. Cohort studies or cohort analyses of randomized, controlled trials that compared mortality between those with and without chronically reduced kidney function were included. Studies were excluded from review when participants were followed for < 1 yr or had ESRD. Two reviewers independently extracted data on study setting, quality, participant and renal function characteristics, and outcomes. Thirty-nine studies that followed a total of 1,371,990 participants were reviewed. The unadjusted relative risk for mortality in participants with reduced kidney function compared with those without ranged from 0.94 to 5.0 and was significantly more than 1.0 in 93% of cohorts. Among the 16 studies that provided suitable data, the absolute risk for death increased exponentially with decreasing renal function. Fourteen cohorts described the risk for mortality from reduced kidney function, after adjustment for other established risk factors. Although adjusted relative hazards were consistently lower than unadjusted relative risks (median reduction 17%), they remained significantly more than 1.0 in 71% of cohorts. This review supports current guidelines that identify individuals with CKD as being at high risk for cardiovascular mortality. Determining which interventions best offset this risk remains a health priority.
Cardiovascular Diseases↗
The direct and indirect economic costs incurred by living kidney donors-a systematic review.
BACKGROUND: Despite the many benefits of living donor kidney transplantation, economic consequences can result for donors. We reviewed studies which quantified the direct and indirect costs incurred by living kidney donors, in order to understand the strengths and limitations of existing literature. METHODS: We identified relevant studies in MEDLINE, EMBASE and ECONOLIT bibliographic databases, in the Science Citation Index and study reference lists. Any study which reported at least one cost relevant to donors was included. The accuracy of abstracted data was verified by two reviewers and reported in year 2004 US dollars. RESULTS: Thirty-five studies from 12 countries described costs incurred by individuals who donated between the years 1964 and 2003. No study comprehensively quantified all relevant expenses-the sum of select costs considered in one US study averaged Dollars 837 per donor and ranged from Dollars 0 to 28,906. Travel and/or accommodation costs were incurred by 9-99% of donors, and were higher in countries with a larger land mass. Post-discharge analgesics were required by 4-24% of donors, but prescription costs were not reported. Between 14 and 30% of donors incurred costs for lost income, with an average loss of Dollars 3386 in one study from the UK and Dollars 682 in another study from the Netherlands. Costs for dependent care were incurred by 9-44% of donors, while costs for domestic help were incurred by 8% of donors. CONCLUSIONS: Donors incur many types of costs attributable to kidney donation and the total costs are certainly higher than previously reported. To guide informed consent and fair reimbursement policies, further data on all relevant costs, preferably from a detailed prospective multi-centre cohort study, are required.
Compensation and Redress↗
Living organ donors face financial barriers: a national reimbursement policy is needed.
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Altruism↗
A gradient of acute gastroenteritis was characterized, to assess risk of long-term health sequelae after drinking bacterial-contaminated water.
OBJECTIVE: A municipal water system became contaminated with Escherichia coli O157:H7 and Campylobacter spp. Beginning 2 years after an outbreak, all residents from the region were invited to participate in a cohort study assessing the risk of long-term sequelae. We aimed to develop a method to grade the accuracy and severity of self-reported acute symptoms. STUDY DESIGN AND SETTING: We corroborated participant survey responses with health records at the time of the outbreak. Of the 4,135 participants, 1,388 were asymptomatic during the outbreak, 1,752 had symptoms of acute self-limited gastroenteritis that could neither be confirmed nor refuted by prior health records, and 995 had symptoms that necessitated medical attention (and thus were confirmed by prior health records). RESULTS: The gradient related to the severity of acute symptoms. Compared to those with unconfirmed gastroenteritis, participants with confirmed gastroenteritis were more likely to describe fever, bloody diarrhea, and prolonged diarrhea (all P < .03). The gradient also correlated with long-term plausible outcomes, including chronic gastrointestinal symptoms, chronic symptoms of arthritis or depression, and the avoidance of municipal water ingestion after the outbreak (P for trend consistently < .03). Conversely, for the outcome of chronic tinnitus, an association was neither expected nor observed (P for trend = .26). CONCLUSION: We successfully characterized a gradient to be used in future primary analyses assessing the risk of long-term health sequelae after an outbreak.
Acute Disease↗
Incidence and epidemiology of irritable bowel syndrome after a large waterborne outbreak of bacterial dysentery.
BACKGROUND & AIMS: Postinfectious irritable bowel syndrome (PI-IBS) is a common clinical phenomenon. To better define its incidence and epidemiology, a large cohort study was initiated after the contamination of a municipal water supply led to a large outbreak of acute Escherichia coli 0157:H7 and Campylobacter jejuni gastroenteritis. METHODS: Local residents were invited to undergo structured assessments at research clinics established 2 years after the outbreak. Permanent adult residents with no prior history of inflammatory bowel disease or IBS were eligible. Standardized questionnaires defined past and current health. The cohort was divided into controls without gastroenteritis, subjects with clinically suspected gastroenteritis, and subjects with only self-reported gastroenteritis that could not be substantiated by another source. A modified Bowel Disease Questionnaire identified IBS according to Rome criteria. The incidence and epidemiology of PI-IBS was characterized. Risk factors were assessed using multiple logistic regression. RESULTS: There were 2069 eligible study participants. Rome I criteria were met by 71 of 701 controls (10.1%) vs 249 of 904 subjects with self-reported gastroenteritis (27.5%) and 168 of 464 subjects with clinically suspected gastroenteritis (36.2%) (all comparisons, P < 001). Independent risk factors for PI-IBS included younger age, female sex, bloody stools, abdominal cramps, weight loss, and prolonged diarrhea. PI-IBS was more likely than sporadic IBS to show diarrhea-predominant features. CONCLUSIONS: PI-IBS is common after gastroenteritis from water contamination and often is diarrhea-predominant. Characteristics of the acute illness identify patients at increased risk for PI-IBS.
Campylobacter Infections↗
The International Quotidian Dialysis Registry: annual report 2006.
Interest in short daily and nocturnal hemodialysis (HD) regimens continues to grow worldwide. Despite growing optimism that these therapies will afford better patient outcomes over conventional HD, the current literature has not been viewed as sufficiently compelling to affect widespread implementation in most jurisdictions. Before these therapies can gain wider acceptance, larger and more rigorous studies will likely be needed. In June 2004, the Quotidian Dialysis Registry, based at the Lawson Health Research Institute at the University of Western Ontario, Canada, began recruiting patients across North America. By using an Internet-based data entry platform, patients from various centers worldwide will eventually be recruited, and studied prospectively. This paper constitutes the second annual update on patient and center recruitment, patient and treatment characteristics, and future directions for the registry.
Adult↗
Review: the renoprotective effects of ACE inhibitors and ARBs independent of blood pressure control are uncertain.
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Comment↗
Randomized trials of frequent hemodialysis--infinite possibilities.
Current understanding of the benefits of daily and nocturnal hemodialysis is limited by the designs used in previous studies which tested these therapies. There is increasing momentum to evaluate these therapies in randomized controlled trials. By establishing the efficacy, safety and delivery of daily and nocturnal hemodialysis, such trials will guide policy and funding decisions regarding the role of these therapies in the treatment of end-stage renal disease. However, in designing trials that fulfill these goals, many questions arise. What study population should be used? How should the intervention be defined? Which outcomes should be evaluated? Several methodological issues particular to trials of frequent dialysis require additional consideration. The 'ideal' trial in terms of methods must be balanced against the feasibility of implementation and budgetary constraints. Here, we explore some of these issues.
Adult↗
Plasma exchange when myeloma presents as acute renal failure: a randomized, controlled trial.
BACKGROUND: Two small, randomized trials provide conflicting evidence about the benefits of plasma exchange for patients with acute renal failure at the onset of multiple myeloma. OBJECTIVE: To assess the effect of 5 to 7 plasma exchanges on a composite outcome in patients with acute renal failure at the onset of multiple myeloma. DESIGN: Randomized, open, controlled trial, stratified by chemotherapy and dialysis dependence, conducted from 1998 to 2004. SETTING: Hospital plasma exchange units in 14 Canadian medical centers. PARTICIPANTS: 104 patients between 18 and 81 years of age with acute renal failure at the onset of myeloma. INTERVENTION: Study participants were randomly assigned to conventional therapy plus 5 to 7 plasma exchanges of 50 mL per kg of body weight of 5% human serum albumin for 10 days or conventional therapy alone. Ninety-seven participants completed the 6-month follow-up. MEASUREMENTS: The primary outcome was a composite measure of death, dialysis dependence, or glomerular filtration rate less than 0.29 mL x s(-2) x m(-2) (<30 mL/min per 1.73 m2). RESULTS: At enrollment, the plasma exchange and control groups were similar for dialysis dependence, chemotherapy, sex, age, hypercalcemia, serum albumin level, 24-hour urine protein level, serum creatinine level, and Durie-Salmon staging. The primary composite end point occurred in 33 of 57 (57.9%) patients in the plasma exchange group and in 27 of 39 (69.2%) patients in the control group (difference between groups, 11.3% [95% CI, -8.3% to 29.1%]; P = 0.36). One third of patients in each group died. LIMITATIONS: The study was small, used a composite outcome, and did not use renal biopsy as an inclusion criterion. Recruiting physicians were blinded to treatment allocation but not to treatment thereafter. CONCLUSIONS: In patients with acute renal failure at the onset of multiple myeloma, there is no conclusive evidence that 5 to 7 plasma exchanges substantially reduce a composite outcome of death, dialysis dependence, or glomerular filtration rate less than 0.29 mL.s(-2).m(-2) (<30 mL/min per 1.73 m2) at 6 months.
Acute Kidney Injury↗
The tension between E-health innovation and E-valuation.
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Cost-Benefit Analysis↗
Risk of hypertension and reduced kidney function after acute gastroenteritis from bacteria-contaminated drinking water.
BACKGROUND: The long-term health consequences of acute bacterial gastroenteritis remain uncertain. We studied the risk of hypertension and reduced kidney function after an outbreak of acute gastroenteritis due to contamination of a regional drinking water supply with Escherichia coli O157:H7 and Campylobacter species. METHODS: A total of 1958 adults with no known history of hypertension or kidney disease before the outbreak participated in a long-term follow-up study. Of the participants, 675 had been asymptomatic during the outbreak, 909 had had moderate symptoms of acute self-limited gastroenteritis, and 374 had had severe symptoms that necessitated medical attention. The outcomes of interest were a diagnosis of hypertension or the presence of reduced kidney function and albuminuria during the follow-up period. RESULTS: After a mean follow-up of 3.7 years after the outbreak, hypertension was diagnosed in 27.0% of participants who had been asymptomatic during the outbreak and in 32.3% and 35.9% of those who had had moderate and severe symptoms of acute gastroenteritis respectively (trend p = 0.009). Compared with the asymptomatic participants, those with moderate and severe symptoms of gastroenteritis had an adjusted relative risk of hypertension of 1.15 (95% confidence interval [CI] 0.97-1.35) and 1.28 (95% CI 1.04-1.56) respectively. A similar graded association was seen for reduced kidney function, defined as the presence of an estimated glomerular filtration rate below 60 mL/min per 1.73 m2 (trend p = 0.03). No association was observed between gastroenteritis and the subsequent risk of albuminuria. INTERPRETATION: Acute bacterial gastroenteritis necessitating medical attention was associated with an increased risk of hypertension and reduced kidney function 4 years after infection. Maintaining safe drinking water remains essential to human health, as transient bacterial contaminations may have implications well beyond a period of acute self-limited illness.
Acute Disease↗
Measured creatinine clearance from timed urine collections substantially overestimates glomerular filtration rate in patients with liver cirrhosis: a systematic review and individual patient meta-analysis.
BACKGROUND: Accurate glomerular filtration rate (GFR) assessment in patients with liver cirrhosis is important for prognostication, chronic kidney disease staging, drug dosing and identifying combined liver-kidney transplantation candidates. The objective of this study was to review the accuracy of measured creatinine clearance (MCrCl) from timed urine collections for estimating true GFR. METHODS: A systematic review and individual patient meta-analysis was performed. MEDLINE, old MEDLINE, Index Medicus and Cochrane library bibliographic databases and conference proceedings were searched up to June 2004. Reference lists of relevant studies were searched and experts were contacted. Comparative diagnostic studies describing stable adult patients with cirrhosis categorized according to the Child-Pugh classification were included if a gold standard GFR measurement was performed within 3 days of MCrCl. Individual patient data were abstracted from graphs of primary articles to allow a pooled analysis of agreement between renal measures. RESULTS: Seven studies of 193 patients from 1974 to 2002 were summarized. MCrCl overestimated inulin clearance (CIn) by a mean of +13 ml/min/1.73 m2 and the limits of agreement (mean of the differences+/-2 SD) were +60 ml/min/1.73 m2 and -34 ml/min/1.73 m2. This overestimation was highest in patients with lower GFR. The mean clearance ratios [95% confidence interval (CI)] between MCrCl and CIn in the high (> or =60 ml/min/1.73 m2) and low (<60 ml/min/1.73 m2) GFR subgroups were 1.18 (1.12-1.23) and 1.49 (1.33-1.66), respectively (P<0.0001). Fourteen percent of patients with a MCrCl > or =60 ml/min/1.73 m2 had a CIn of <30 ml/min/1.73 m2. CONCLUSIONS: For patients with liver cirrhosis, MCrCl from timed urine collections consistently overestimates the true GFR. For patients requiring complete clinical evaluation, GFR assessment by CIn is justified.
Adult↗
Identifying individuals with a reduced GFR using ambulatory laboratory database surveillance.
The use of outpatient laboratory databases to identify people with a low GFR may be part of an effective strategy to increase their use of treatments to prevent kidney failure. All renal function data from 17 independent outpatient laboratories in Eastern Ontario were combined to determine the proportion of adults with at least one serum creatinine measurement during a 1-yr period. The detection rates of low GFR were measured using different algorithms, and what proportion of identified low GFR was transient was considered. Canadian census data were used to calculate rates and proportions. Renal function testing was common. Of the 1,090,000 adult residents, 32% of the entire population and 63% of seniors had at least one serum creatinine measured during the study year. Sixteen percent of the population (49% of those with tests performed) had at least one GFR <80 ml/min per 1.73 m2, 5% (16%) had at least one GFR <60 ml/min per 1.73 m2, and 0.6% (1.7%) had at least one GFR <30 ml/min per 1.73 m2. Low GFR were usually not transient: 68% of individuals with subsequent testing at least 30 d later had a similar or worse GFR. Ambulatory laboratory database case finding, particularly in older patients, seems to be a promising method for easily identifying large segments of the population with persistent reductions in GFR. Whether such identification leads to improved health outcomes warrants further study.
Algorithms↗
Effects of computerized clinical decision support systems on practitioner performance and patient outcomes: a systematic review.
CONTEXT: Developers of health care software have attributed improvements in patient care to these applications. As with any health care intervention, such claims require confirmation in clinical trials. OBJECTIVES: To review controlled trials assessing the effects of computerized clinical decision support systems (CDSSs) and to identify study characteristics predicting benefit. DATA SOURCES: We updated our earlier reviews by searching the MEDLINE, EMBASE, Cochrane Library, Inspec, and ISI databases and consulting reference lists through September 2004. Authors of 64 primary studies confirmed data or provided additional information. STUDY SELECTION: We included randomized and nonrandomized controlled trials that evaluated the effect of a CDSS compared with care provided without a CDSS on practitioner performance or patient outcomes. DATA EXTRACTION: Teams of 2 reviewers independently abstracted data on methods, setting, CDSS and patient characteristics, and outcomes. DATA SYNTHESIS: One hundred studies met our inclusion criteria. The number and methodologic quality of studies improved over time. The CDSS improved practitioner performance in 62 (64%) of the 97 studies assessing this outcome, including 4 (40%) of 10 diagnostic systems, 16 (76%) of 21 reminder systems, 23 (62%) of 37 disease management systems, and 19 (66%) of 29 drug-dosing or prescribing systems. Fifty-two trials assessed 1 or more patient outcomes, of which 7 trials (13%) reported improvements. Improved practitioner performance was associated with CDSSs that automatically prompted users compared with requiring users to activate the system (success in 73% of trials vs 47%; P = .02) and studies in which the authors also developed the CDSS software compared with studies in which the authors were not the developers (74% success vs 28%; respectively, P = .001). CONCLUSIONS: Many CDSSs improve practitioner performance. To date, the effects on patient outcomes remain understudied and, when studied, inconsistent.
Clinical Pharmacy Information Systems↗
Causes of reversible nephrogenic diabetes insipidus: a systematic review.
BACKGROUND: In nephrogenic diabetes insipidus (NDI), the kidney is unable to produce concentrated urine because of the insensitivity of the distal nephron to antidiuretic hormone (arginine vasopressin). In settings in which fluid intake cannot be maintained, this may result in severe dehydration and electrolyte imbalances. The risk for conversion of reversible to irreversible NDI seems to be a potential complication. This review summarizes the reversible causes of acquired NDI to facilitate earlier recognition and more effective treatment by clinicians. METHODS: Two reviewers independently searched MEDLINE, Experta Medica (EMBASE), and ISI bibliographic databases. Human studies that described NDI caused by drugs, substances, or metabolic disturbances were included. To evaluate the causal role of the risk factor, data were abstracted according to Koch's postulates. RESULTS: One hundred fifty-five studies published between 1957 and March 2004 described 30 risk factors. Of 155 studies, 58 studies provided a "definite" diagnosis of NDI; 83 studies, a "probable" diagnosis; and 14 studies, a "possible" diagnosis. Nine factors were considered "definite" causes of NDI; 15 factors, "probable" causes; and 6 factors, "possible" causes. The most reported risk factors were lithium (84 studies), antibiotics (16 studies), antifungals (11 studies), antineoplastic agents (9 studies), antivirals (8 studies), and metabolic disturbances (8 studies). Duration of NDI reversal, as well as conversion to irreversible symptoms, seemed to depend on the duration of exposure. CONCLUSION: Most risk factors for reversible NDI were medications, and their identification and removal resulted in resolution of the condition. Long-term treatment with lithium seemed to result in irreversible NDI.
Anti-Infective Agents↗