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Featured researches published by Peter Guarino.


The New England Journal of Medicine | 2010

Robot-Assisted Therapy for Long-Term Upper-Limb Impairment after Stroke

Albert C. Lo; Peter Guarino; Lorie Richards; Jodie K. Haselkorn; George F. Wittenberg; Daniel G. Federman; Robert J. Ringer; Todd H. Wagner; Hermano Igo Krebs; Bruce T. Volpe; Christopher T. Bever; Dawn M. Bravata; Pamela W. Duncan; Barbara H. Corn; Alysia D. Maffucci; Stephen E. Nadeau; Susan S. Conroy; Janet M. Powell; Grant D. Huang; Peter Peduzzi

BACKGROUND Effective rehabilitative therapies are needed for patients with long-term deficits after stroke. METHODS In this multicenter, randomized, controlled trial involving 127 patients with moderate-to-severe upper-limb impairment 6 months or more after a stroke, we randomly assigned 49 patients to receive intensive robot-assisted therapy, 50 to receive intensive comparison therapy, and 28 to receive usual care. Therapy consisted of 36 1-hour sessions over a period of 12 weeks. The primary outcome was a change in motor function, as measured on the Fugl-Meyer Assessment of Sensorimotor Recovery after Stroke, at 12 weeks. Secondary outcomes were scores on the Wolf Motor Function Test and the Stroke Impact Scale. Secondary analyses assessed the treatment effect at 36 weeks. RESULTS At 12 weeks, the mean Fugl-Meyer score for patients receiving robot-assisted therapy was better than that for patients receiving usual care (difference, 2.17 points; 95% confidence interval [CI], -0.23 to 4.58) and worse than that for patients receiving intensive comparison therapy (difference, -0.14 points; 95% CI, -2.94 to 2.65), but the differences were not significant. The results on the Stroke Impact Scale were significantly better for patients receiving robot-assisted therapy than for those receiving usual care (difference, 7.64 points; 95% CI, 2.03 to 13.24). No other treatment comparisons were significant at 12 weeks. Secondary analyses showed that at 36 weeks, robot-assisted therapy significantly improved the Fugl-Meyer score (difference, 2.88 points; 95% CI, 0.57 to 5.18) and the time on the Wolf Motor Function Test (difference, -8.10 seconds; 95% CI, -13.61 to -2.60) as compared with usual care but not with intensive therapy. No serious adverse events were reported. CONCLUSIONS In patients with long-term upper-limb deficits after stroke, robot-assisted therapy did not significantly improve motor function at 12 weeks, as compared with usual care or intensive therapy. In secondary analyses, robot-assisted therapy improved outcomes over 36 weeks as compared with usual care but not with intensive therapy. (ClinicalTrials.gov number, NCT00372411.)


The New England Journal of Medicine | 2013

Combined Angiotensin Inhibition for the Treatment of Diabetic Nephropathy

Linda F. Fried; Nicholas V. Emanuele; Jane H. Zhang; Mary T. Brophy; Todd A. Conner; William C. Duckworth; David J. Leehey; Peter A. McCullough; Theresa Z. O'Connor; Paul M. Palevsky; Robert F. Reilly; Stephen L. Seliger; Stuart R. Warren; Suzanne Watnick; Peter Peduzzi; Peter Guarino

BACKGROUND Combination therapy with angiotensin-converting-enzyme (ACE) inhibitors and angiotensin-receptor blockers (ARBs) decreases proteinuria; however, its safety and effect on the progression of kidney disease are uncertain. Methods We provided losartan (at a dose of 100 mg per day) to patients with type 2 diabetes, a urinary albumin-to-creatinine ratio (with albumin measured in milligrams and creatinine measured in grams) of at least 300, and an estimated glomerular filtration rate (GFR) of 30.0 to 89.9 ml per minute per 1.73 m(2) of body-surface area and then randomly assigned them to receive lisinopril (at a dose of 10 to 40 mg per day) or placebo. The primary end point was the first occurrence of a change in the estimated GFR (a decline of ≥ 30 ml per minute per 1.73 m(2) if the initial estimated GFR was ≥ 60 ml per minute per 1.73 m(2) or a decline of ≥ 50% if the initial estimated GFR was <60 ml per minute per 1.73 m(2)), end-stage renal disease (ESRD), or death. The secondary renal end point was the first occurrence of a decline in the estimated GFR or ESRD. Safety outcomes included mortality, hyperkalemia, and acute kidney injury. Results The study was stopped early owing to safety concerns. Among 1448 randomly assigned patients with a median follow-up of 2.2 years, there were 152 primary end-point events in the monotherapy group and 132 in the combination-therapy group (hazard ratio with combination therapy, 0.88; 95% confidence interval [CI], 0.70 to 1.12; P=0.30). A trend toward a benefit from combination therapy with respect to the secondary end point (hazard ratio, 0.78; 95% CI, 0.58 to 1.05; P=0.10) decreased with time (P=0.02 for nonproportionality). There was no benefit with respect to mortality (hazard ratio for death, 1.04; 95% CI, 0.73 to 1.49; P=0.75) or cardiovascular events. Combination therapy increased the risk of hyperkalemia (6.3 events per 100 person-years, vs. 2.6 events per 100 person-years with monotherapy; P<0.001) and acute kidney injury (12.2 vs. 6.7 events per 100 person-years, P<0.001). Conclusions Combination therapy with an ACE inhibitor and an ARB was associated with an increased risk of adverse events among patients with diabetic nephropathy. (Funded by the Cooperative Studies Program of the Department of Veterans Affairs Office of Research and Development; VA NEPHRON-D ClinicalTrials.gov number, NCT00555217.).


The Lancet | 2013

Effects of folic acid supplementation on overall and site-specific cancer incidence during the randomised trials: meta-analyses of data on 50 000 individuals

Stein Emil Vollset; Robert Clarke; Sarah Lewington; Marta Ebbing; Jim Halsey; Eva Lonn; Jane Armitage; JoAnn E. Manson; Graeme J. Hankey; J. David Spence; Pilar Galan; Kaare H. Bønaa; Rex L. Jamison; J. Michael Gaziano; Peter Guarino; John A. Baron; Richard F. Logan; Edward Giovannucci; Martin den Heijer; Per Magne Ueland; Derrick Bennett; Rory Collins; Richard Peto

BACKGROUND Some countries fortify flour with folic acid to prevent neural tube defects but others do not, partly because of concerns about possible cancer risks. We aimed to assess any effects on site-specific cancer rates in the randomised trials of folic acid supplementation, at doses higher than those from fortification. METHODS In these meta-analyses, we sought all trials completed before 2011 that compared folic acid versus placebo, had scheduled treatment duration at least 1 year, included at least 500 participants, and recorded data on cancer incidence. We obtained individual participant datasets that included 49,621 participants in all 13 such trials (ten trials of folic acid for prevention of cardiovascular disease [n=46,969] and three trials in patients with colorectal adenoma [n=2652]). All these trials were evenly randomised. The main outcome was incident cancer (ignoring non-melanoma skin cancer) during the scheduled treatment period (among participants who were still free of cancer). We compared those allocated folic acid with those allocated placebo, and used log-rank analyses to calculate the cancer incidence rate ratio (RR). FINDINGS During a weighted average scheduled treatment duration of 5·2 years, allocation to folic acid quadrupled plasma concentrations of folic acid (57·3 nmol/L for the folic acid groups vs 13·5 nmol/L for the placebo groups), but had no significant effect on overall cancer incidence (1904 cancers in the folic acid groups vs 1809 cancers in the placebo groups, RR 1·06, 95% CI 0·99–1·13, p=0·10). There was no trend towards greater effect with longer treatment. There was no significant heterogeneity between the results of the 13 individual trials (p=0·23), or between the two overall results in the cadiovascular prevention trials and the adenoma trials (p=0·13). Moreover, there was no significant effect of folic acid supplementation on the incidence of cancer of the large intestine, prostate, lung, breast, or any other specific site. INTERPRETATION Folic acid supplementation does not substantially increase or decrease incidence of site-specific cancer during the first 5 years of treatment. Fortification of flour and other cereal products involves doses of folic acid that are, on average, an order of magnitude smaller than the doses used in these trials. FUNDING British Heart Foundation, Medical Research Council, Cancer Research UK, Food Standards Agency.


Journal of Clinical Epidemiology | 2016

Million Veteran Program: A mega-biobank to study genetic influences on health and disease.

John Michael Gaziano; John Concato; Mary T. Brophy; Louis D. Fiore; Saiju Pyarajan; James Breeling; Stacey Whitbourne; Jennifer Deen; Colleen Shannon; Donald E. Humphries; Peter Guarino; Mihaela Aslan; Daniel Anderson; Rene LaFleur; Timothy R. Hammond; Kendra Schaa; Jennifer Moser; Grant D. Huang; Sumitra Muralidhar; Ronald Przygodzki; Timothy J. O'Leary

OBJECTIVE To describe the design and ongoing conduct of the Million Veteran Program (MVP), as an observational cohort study and mega-biobank in the Department of Veterans Affairs (VA) health care system. STUDY DESIGN AND SETTING Data are being collected from participants using questionnaires, the VA electronic health record, and a blood sample for genomic and other testing. Several ongoing projects are linked to MVP, both as peer-reviewed research studies and as activities to help develop an infrastructure for future, broad-based research uses. RESULTS Formal planning for MVP commenced in 2009; the protocol was approved in 2010, and enrollment began in 2011. As of August 3, 2015, and with a steady state of ≈50 recruiting sites nationwide, N = 397,104 veterans have been enrolled. Among N = 199,348 with currently available genotyping data, most participants (as expected) are male (92.0%) between the ages of 50 and 69 years (55.0%). On the basis of self-reported race, white (77.2%) and African American (13.5%) populations are well represented. CONCLUSIONS By helping to promote the future integration of genetic testing in health care delivery, including clinical decision making, the MVP is designed to contribute to the development of precision medicine.


Neurorehabilitation and Neural Repair | 2009

Multicenter Randomized Trial of Robot-Assisted Rehabilitation for Chronic Stroke: Methods and Entry Characteristics for VA ROBOTICS

Albert C. Lo; Peter Guarino; Hermano Igo Krebs; Bruce T. Volpe; Christopher T. Bever; Pamela W. Duncan; Robert J. Ringer; Todd H. Wagner; Lorie Richards; Dawn M. Bravata; Jodie K. Haselkorn; George F. Wittenberg; Daniel G. Federman; Barbara H. Corn; Alysia D. Maffucci; Peter Peduzzi

Background. Chronic upper extremity impairment due to stroke has significant medical, psychosocial, and financial consequences, but few studies have examined the effectiveness of rehabilitation therapy during the chronic stroke period. Objective. To test the safety and efficacy of the MIT-Manus robotic device for chronic upper extremity impairment following stroke. Methods. The VA Cooperative Studies Program initiated a multicenter, randomized, controlled trial in November 2006 (VA ROBOTICS). Participants with upper extremity impairment ≥6 months poststroke were randomized to robot-assisted therapy (RT), intensive comparison therapy (ICT), or usual care (UC). RT and ICT consisted of three 1-hour treatment sessions per week for 12 weeks. The primary outcome was change in the Fugl-Meyer Assessment upper extremity motor function score at 12 weeks relative to baseline. Secondary outcomes included the Wolf Motor Function Test and the Stroke Impact Scale. Results. A total of 127 participants were randomized: 49 to RT, 50 to ICT, and 28 to UC. The majority of participants were male (96%), with a mean age of 65 years. The primary stroke type was ischemic (85%), and 58% of strokes occurred in the anterior circulation. Twenty percent of the participants reported a stroke in addition to their index stroke. The average time from the index stroke to enrollment was 56 months (range, 6 months to 24 years). The mean Fugl-Meyer score at entry was 18.9. Conclusions. VA ROBOTICS demonstrates the feasibility of conducting multicenter clinical trials to rigorously test new rehabilitative devices before their introduction to clinical practice. The results are expected in early 2010.


American Journal of Kidney Diseases | 2009

Homocysteine Lowering and Cognition in CKD: The Veterans Affairs Homocysteine Study

Christopher B. Brady; J. Michael Gaziano; Roberta A. Cxypoliski; Peter Guarino; James S. Kaufman; Stuart R. Warren; Pamela Hartigan; David S. Goldfarb; Rex L. Jamison

BACKGROUND Individuals with advanced chronic kidney disease (CKD) and end-stage renal disease (ESRD) have high plasma total homocysteine (tHcy) levels, which may be a risk factor for cognitive impairment. Whether treatment with high-dose B vitamins to decrease high tHcy levels improves cognition in persons with kidney disease is unknown. STUDY DESIGN Randomized controlled trial. SETTING & PARTICIPANTS A substudy of 659 patients (mean age, 67.3 +/- 11.7 years) who participated in a randomized double-blind clinical trial 5 years in duration conducted in 36 US Department of Veterans Affairs medical centers of the effect on all-cause mortality of vitamin-induced lowering of plasma tHcy level. 236 (35.8%) were treated by using dialysis (ESRD) and 423 (64.2%) had a Cockcroft-Gault estimated creatinine clearance of 30 mL/min or less (advanced CKD). All had high tHcy levels (> or =15 micromol/L) at baseline. Cognitive assessments began during the follow-up period of the main trial 3 years after treatment began; participants subsequently were retested 1 year later to assess cognitive change. INTERVENTION Daily high-dose B vitamin capsule (40 mg of folic acid, 100 mg of vitamin B(6), and 2 mg of vitamin B(12)) or placebo. OUTCOMES Cognitive function at initial assessment and 1 year later. MEASUREMENTS Telephone Interview of Cognitive Status-modified, supplemented with attention, working memory, and executive function tests. RESULTS Initial cognitive function was impaired in approximately 19% of patients regardless of treatment assignment (vitamin or placebo) or kidney disease status (advanced CKD or ESRD). Treatment decreased tHcy levels by 26.7%. Unadjusted and adjusted analyses showed that treatment did not improve initial cognitive outcomes or affect subsequent cognitive status 1 year later. LIMITATIONS Cognitive assessments began after treatment was initiated; cognitive assessment was limited. CONCLUSION Treatment with high daily doses of B vitamins, which decreased tHcy levels, did not affect cognitive outcomes in patients with advanced CKD and ESRD.


American Journal of Kidney Diseases | 2009

Original InvestigationPathogenesis and Treatment of Kidney DiseaseHomocysteine Lowering and Cognition in CKD: The Veterans Affairs Homocysteine Study

Christopher B. Brady; J. Michael Gaziano; Roberta A. Cxypoliski; Peter Guarino; James S. Kaufman; Stuart R. Warren; Pamela Hartigan; David S. Goldfarb; Rex L. Jamison

BACKGROUND Individuals with advanced chronic kidney disease (CKD) and end-stage renal disease (ESRD) have high plasma total homocysteine (tHcy) levels, which may be a risk factor for cognitive impairment. Whether treatment with high-dose B vitamins to decrease high tHcy levels improves cognition in persons with kidney disease is unknown. STUDY DESIGN Randomized controlled trial. SETTING & PARTICIPANTS A substudy of 659 patients (mean age, 67.3 +/- 11.7 years) who participated in a randomized double-blind clinical trial 5 years in duration conducted in 36 US Department of Veterans Affairs medical centers of the effect on all-cause mortality of vitamin-induced lowering of plasma tHcy level. 236 (35.8%) were treated by using dialysis (ESRD) and 423 (64.2%) had a Cockcroft-Gault estimated creatinine clearance of 30 mL/min or less (advanced CKD). All had high tHcy levels (> or =15 micromol/L) at baseline. Cognitive assessments began during the follow-up period of the main trial 3 years after treatment began; participants subsequently were retested 1 year later to assess cognitive change. INTERVENTION Daily high-dose B vitamin capsule (40 mg of folic acid, 100 mg of vitamin B(6), and 2 mg of vitamin B(12)) or placebo. OUTCOMES Cognitive function at initial assessment and 1 year later. MEASUREMENTS Telephone Interview of Cognitive Status-modified, supplemented with attention, working memory, and executive function tests. RESULTS Initial cognitive function was impaired in approximately 19% of patients regardless of treatment assignment (vitamin or placebo) or kidney disease status (advanced CKD or ESRD). Treatment decreased tHcy levels by 26.7%. Unadjusted and adjusted analyses showed that treatment did not improve initial cognitive outcomes or affect subsequent cognitive status 1 year later. LIMITATIONS Cognitive assessments began after treatment was initiated; cognitive assessment was limited. CONCLUSION Treatment with high daily doses of B vitamins, which decreased tHcy levels, did not affect cognitive outcomes in patients with advanced CKD and ESRD.


Clinical Trials | 2006

Consumer involvement in consent document development: a multicenter cluster randomized trial to assess study participants' understanding

Peter Guarino; Diana Elbourne; James Carpenter; Peter Peduzzi

Background Despite widespread agreement on the importance of informed consent in clinical research, uncertainty remains about the adequacy of current consent procedures and documentation. Methods The objective of the study was to compare an informed consent document developed by a consumer group of potential study participants to one developed by the study investigators. The study was a cluster randomized, controlled study embedded in a ‘parent’ randomized controlled trial of 1092 participants with Gulf War veterans’ illnesses recruited in 1999–2000 at 20 US medical centers. Centers were randomized to the investigator-developed or participant-developed consent document. The primary outcome measure was an Informed Consent Questionnaire-4 (ICQ-4), a validated four-item scale measuring self-reported participant understanding scored from 0 to 1. Secondary outcomes included the Client Satisfaction Questionnaire-8 and measures of study refusal and adherence to the parent trial protocol. Results There were no significant differences between consent documents on the ICQ-4 score overall or at any of the time points. Mean (95% CI) treatment differences ranged from 0.020 (0.015, 0.055) (better understanding) at entry to 0.021 (0.054, 0.012) (worse understanding) at three-months for the participant versus the investigator document group. There were also no significant differences in satisfaction, adherence to the protocol, or in the proportion of patients who refused to participate in the trial. Limitations The consumer group may not have been representative of the study participants and they did not suggest dramatic changes to the consent document. The outcome assessment questionnaire was not validated prior to the trials initiation. Conclusions Consumer modification of the consent document did not lead to either benefit or harm in understanding, satisfaction, or study refusal and adherence rates. This study did demonstrate, however, that embedding consent studies in a clinical trial is feasible and can address important questions about informed consent without disrupting the primary study.


American Heart Journal | 2014

Pioglitazone for secondary prevention after ischemic stroke and transient ischemic attack: Rationale and design of the Insulin Resistance Intervention after Stroke Trial

Catherine M. Viscoli; Lawrence M. Brass; Antonio Carolei; Robin Conwit; Gary A Ford; Karen L. Furie; Mark Gorman; Peter Guarino; Silvio E. Inzucchi; Anne M. Lovejoy; Mark W. Parsons; Peter Peduzzi; Peter A. Ringleb; Gregory G. Schwartz; J. David Spence; David Tanne; Lawrence H. Young; Walter N. Kernan

BACKGROUND Recurrent vascular events remain a major source of morbidity and mortality after stroke or transient ischemic attack (TIA). The IRIS Trial is evaluating an approach to secondary prevention based on the established association between insulin resistance and increased risk for ischemic vascular events. Specifically, IRIS will test the effectiveness of pioglitazone, an insulin-sensitizing drug of the thiazolidinedione class, for reducing the risk for stroke and myocardial infarction (MI) among insulin resistant, nondiabetic patients with a recent ischemic stroke or TIA. DESIGN Eligible patients for IRIS must have had insulin resistance defined by a Homeostasis Model Assessment-Insulin Resistance > 3.0 without meeting criteria for diabetes. Within 6 months of the index stroke or TIA, patients were randomly assigned to pioglitazone (titrated from 15 to 45 mg/d) or matching placebo and followed for up to 5 years. The primary outcome is time to stroke or MI. Secondary outcomes include time to stroke alone, acute coronary syndrome, diabetes, cognitive decline, and all-cause mortality. Enrollment of 3,876 participants from 179 sites in 7 countries was completed in January 2013. Participant follow-up will continue until July 2015. SUMMARY The IRIS Trial will determine whether treatment with pioglitazone improves cardiovascular outcomes of nondiabetic, insulin-resistant patients with stroke or TIA. Results are expected in early 2016.


Alzheimers & Dementia | 2014

Vitamin E and memantine in Alzheimer's disease: Clinical trial methods and baseline data

Maurice W. Dysken; Peter Guarino; Julia E. Vertrees; Sanjay Asthana; Mary Sano; Maria Llorente; Muralidhar Pallaki; Susan M. Love; Gerard D. Schellenberg; J. Riley McCarten; Julie Malphurs; Susana Prieto; Peijun Chen; David Loreck; Sara Carney; George Trapp; Rajbir S. Bakshi; Jacobo Mintzer; Judith L. Heidebrink; Ana Vidal-Cardona; Lillian M. Arroyo; Angel R. Cruz; Neil W. Kowall; Mohit P. Chopra; Suzanne Craft; Stephen Thielke; Carolyn Turvey; Catherine Woodman; Kimberly A. Monnell; Kimberly Gordon

Alzheimers disease (AD) has been associated with both oxidative stress and excessive glutamate activity. A clinical trial was designed to compare the effectiveness of (i) alpha‐tocopherol, a vitamin E antioxidant; (ii) memantine (Namenda), an N‐methyl‐D‐aspartate antagonist; (iii) their combination; and (iv) placebo in delaying clinical progression in AD.

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J. Michael Gaziano

Brigham and Women's Hospital

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Albert C. Lo

University of Pennsylvania

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Charles C. Engel

Uniformed Services University of the Health Sciences

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Sam T. Donta

United States Department of Veterans Affairs

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