Search PubMed⌕ Search

Biomedical subjects

Amit X Garg

Publications and source records attributed to Amit X Garg.

At least 19 recordsLinked to original sources
PubMed2006

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↗
PubMed2006

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↗
PubMed2006

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↗
PubMed2005

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↗
PubMed2005

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↗
PubMed2005

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↗
PubMed2005

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↗
PubMed2005

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↗
PubMed2005

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↗
PubMed2005

The International Quotidian Dialysis Registry: annual report 2005.

The International Quotidian Dialysis Registry was designed to collect data describing treatments, characteristics, and outcomes of patients treated with quotidian hemodialysis (HD) worldwide. In July 2004, North American centers were first invited to enroll patients. By March 1, 2005, a total of 70 nocturnal and 8 short-daily HD patients from three Canadian and two US centers were enrolled. As recruitment continues, projected enrollment for 2005 may exceed 200 patients from North America alone. Preliminary analyses indicate that the current registry cohort is younger (mean age, 49.5 +/- 1.6 years) and carries a lower burden of comorbidity than the overall North American HD population. The low event rate expected in this cohort underlines the need for a large sample size if an appropriately powered survival study is to be undertaken. Increasing recruitment in the United States by including HD centers owned or managed by large dialysis organizations, and beginning overseas collaborations to include Australia, New Zealand, Europe, and South America will be the primary areas of focus for 2005.

Adolescent↗
PubMed2005

Microalbuminuria three years after recovery from Escherichia coli O157 hemolytic uremic syndrome due to municipal water contamination.

BACKGROUND: Knowledge of the long-term renal prognosis of diarrhea associated hemolytic uremic syndrome (HUS) is important for patient counseling and follow-up. However, estimates of long-term risk are highly variable, with previous studies not using a healthy control group. METHODS: A municipal water system in the small rural town of Walkerton, Ontario, became contaminated with Escherichia coli O157:H7 in 2000. A cohort of 19 children who recovered from HUS was randomly age- and sex-matched to 38 children with no symptoms at the time of the outbreak. Both groups had detailed renal function testing 3 years after the outbreak, including a random urine albumin to creatinine, glomerular filtration rate estimated by Schwartz formula, and automated and manual blood pressure measurements. RESULTS: There were no baseline differences between the groups with respect to age (mean 4.8 years, range 1 to 15), sex, or birth weight (mean 3.4 kg). In follow-up there were no differences between the groups in body surface area (mean 1.0 m(2)), or in the methods by which renal function was assessed. Compared to the group with no symptoms, patients with HUS demonstrated more microalbuminuria [32% vs. 5%, relative risk 4.8 (95% CI 1.1 to 22.0)], a nonsignificant trend toward lower GFR (124 vs. 134 mL/min per 1.73 m(2)), and no difference in blood pressure. CONCLUSION: Children may demonstrate microalbuminuria 3 years after recovering from HUS. Longer follow-up is needed to determine if this finding has clinical relevance and utility.

Albuminuria↗
PubMed2005

Diabetes during diarrhea-associated hemolytic uremic syndrome: a systematic review and meta-analysis.

OBJECTIVE: To quantify the incidence of diabetes during the acute phase of diarrhea-associated hemolytic uremic syndrome (D + HUS) and to identify features associated with its development. RESEARCH DESIGN AND METHODS: A systematic review and meta-analysis of articles assessing diabetes during D + HUS was conducted. Relevant citations were identified from Medline, Embase, and Institute for Scientific Information Citation Index databases. Bibliographies of relevant articles were hand searched. All articles were independently reviewed for inclusion and data abstraction by two authors. RESULTS: Twenty-one studies from six countries were included. Only 2 studies reported a standard definition of diabetes; 14 defined diabetes as hyperglycemia requiring insulin. The incidence of diabetes during the acute phase of D + HUS could be quantified in a subset of 1,139 children from 13 studies (1966-1998, age 0.2-16 years) and ranged from 0 to 15%, with a pooled incidence of 3.2% (95% CI 1.3-5.1, random-effects model, significant heterogeneity among studies, P = 0.007). Children who developed diabetes were more likely to have severe disease (e.g., presence of coma or seizures, need for dialysis) and had higher mortality than those without diabetes. Twenty-three percent of those who developed diabetes acutely died, and 38% of survivors required long-term insulin (median follow-up 12 months). Recurrence of diabetes was possible up to 60 months after initial recovery. CONCLUSIONS: Children with D + HUS should be observed for diabetes during their acute illness. Consideration should be given to long-term screening of D + HUS survivors for diabetes.

Acute Disease↗
PubMed2004

Midodrine appears to be safe and effective for dialysis-induced hypotension: a systematic review.

BACKGROUND: Dialysis-induced hypotension is an important complication of haemodialysis. Midodrine is an oral alpha-1 agonist that has been used in several small studies to prevent intradialytic hypotension (IDH). METHODS: The authors searched MEDLINE, EMBASE, ASN conference proceedings, and references of potentially relevant articles, and contacted industry (Shire Pharmaceuticals) for unpublished data. Observational studies, randomized controlled trials, crossover studies and pre- and post-intervention design studies with >/=5 haemodialysis patients were included. Study outcomes assessed were: hypotensive symptoms, changes in systolic and/or diastolic blood pressure, dry weight and length of stay after treatment. Data were abstracted on: study design, patient characteristics, intradialytic changes in blood pressure, nadir blood pressure and symptom improvement with midodrine. Thirty-seven full text articles were retrieved and nine met the selection criteria, in addition to one unpublished study. Midodrine dosing regimens ranged from 2.5 to 10 mg of midodrine given 15-30 min before dialysis. RESULTS: Post-dialysis systolic blood pressure was higher by 12.4 mmHg [95% confidence interval (CI) 7.5-17.7] and diastolic pressure was higher by 7.3 mmHg (95% CI 3.7-10.9) during midodrine treatment vs control. Likewise, the nadir systolic blood pressure was higher by 13.3 mmHg (95% CI 8.6-18.0), with a difference in nadir diastolic pressure of 5.9 mmHg (95% CI 2.7-9.1). Six of 10 studies report improvement in symptoms of IDH, and there were no reported serious adverse events ascribed to midodrine. CONCLUSIONS: This systematic review would suggest that midodrine has a role in the therapy of haemodialysis patients experiencing IDH. This conclusion must be viewed with caution, however, given the quality and sample size of the studies included in this review.

Adrenergic alpha-Agonists↗
PubMed2004

An observational study found that authors of randomized controlled trials frequently use concealment of randomization and blinding, despite the failure to report these methods.

BACKGROUND AND OBJECTIVE: Readers of randomized controlled trials (RCTs) commonly assume that what was not reported did not occur. We undertook an observational study to determine whether concealment of randomization or blinding was used in RCTs that failed to report these bias-reducing strategies. METHODS: We recorded the reporting of concealment of randomization and blinding in 105 RCTs. We subsequently contacted the authors and determined if they had used these methodological safeguards. RESULTS: We successfully obtained data from 98 authors. The authors in the full-text publications of these 98 RCTs failed to report the presence or absence of concealment of randomization in 55%, and the blinding status of participants in 26%, health care providers in 64%, data collectors in 84%, outcome assessors in 83%, and data analysts in 96%. In direct contact, authors frequently reported concealing randomization (96%; 95% confidence interval CI=87-100%), blinding participants (20%; 95% CI=7-41%), blinding health care providers (65%; 95% CI=52-77%), blinding data collectors (65%; 95% CI=53-75%), blinding outcome assessors (79%; 95% CI=69-87%), and blinding data analysts (50%; 95% CI=40-60%), despite not reporting the use of these methodological safeguards in their publications. CONCLUSIONS: Readers should not assume that bias-reducing procedures not reported in an RCT did not occur.

Bias↗
PubMed2004

Estimating the prevalence of renal insufficiency in seniors requiring long-term care.

BACKGROUND: Renal function declines with age, but little is known about the extent of renal insufficiency among the institutionalized elderly. The objective of this study was to estimate the prevalence of low glomerular filtration rate (GFR) in a large sample of elderly adults living in long-term care facilities, and to compare two commonly used methods for estimating GFR. METHODS: A total of 9931 residents aged 65 years and older participated in a retrospective cross-sectional study of 87 long-term care facilities in Ontario. GFR was estimated by the Cockcroft-Gault and Modification of Diet in Renal Disease Study (MDRD) equations. The prevalence of low GFR, using the Cockcroft-Gault equation (<30 mL/min), was compared with the MDRD equation (<30 mL/min/1.73 m2). RESULTS: A total of 17.0% (95% CI 15.6 to 18.5) of men and 14.4% (95% CI 13.6 to 15.3) of women had a serum creatinine concentration above the laboratory reported upper reference limit of normal. The prevalence of both elevated serum creatinine and low GFR were observed to increase with age (P < 0.0001). The Cockcroft-Gault equation produced a consistently lower estimate of GFR than did the MDRD equation, a discrepancy most pronounced in the oldest residents. Among all men, a low GFR was more prevalent using the Cockcroft-Gault (10.3%, 95% CI 9.2 to 11.5) than MDRD (3.5%, 95% CI 2.8 to 4.2) equation, with a similar difference also seen in women (23.3%, 95% CI 22.4 to 24.3 versus 4.0%, 95% CI 3.6 to 4.5, respectively). Of all residents whose Cockcroft-Gault estimated GFR was under 30 mL/min, 14.7% (95% CI 13.2 to 16.3) were found to have GFR greater than 60 mL/min/1.73 m2 according to the MDRD equation. CONCLUSION: Age-associated renal impairment is common among elderly long-term care residents, but there exists a clear discrepancy between the Cockcroft-Gault and MDRD equations in predicting GFR. Consideration should be given to medication dose adjustment, based on a practical estimate of GFR. However clarification is needed about which method, if either, is most valid among the frail elderly. Complex patient and societal issues surrounding advanced care directives, treatments associated with renal insufficiency, and, if and when to initiate dialysis, require further attention.

Aged↗