AMPREDICT PROsthetics-Predicting Prosthesis Mobility to Aid in Prosthetic Prescription and Rehabilitation Planning.

OBJECTIVE: To develop and validate a patient-specific multivariable prediction model that uses variables readily available in the electronic medical record to predict 12-month mobility at the time of initial post-amputation prosthetic prescription. The prediction model is designed for patients who have undergone their initial transtibial (TT) or transfemoral (TF) amputation because of complications of diabetes and/or peripheral artery disease. DESIGN: Multi-methodology cohort study that identified patients retrospectively through a large Veteran's Affairs (VA) dataset then prospectively collected their patient-reported mobility. SETTING: The VA Corporate Data Warehouse, the National Prosthetics Patient Database, participant mailings, and phone calls. PARTICIPANTS: Three-hundred fifty-seven veterans who underwent an incident dysvascular TT or TF amputation and received a qualifying lower limb prosthesis between March 1, 2018, and November 30, 2020 (N=357). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: The Amputee Single Item Mobility Measure (AMPSIMM) was divided into a 4-category outcome to predict wheelchair mobility (0-2), and household (3), basic community (4), or advanced community ambulation (5-6). RESULTS: Multinomial logistic lasso regression, a machine learning methodology designed to select variables that most contribute to prediction while controlling for overfitting, led to a final model including 23 predictors of the 4-category AMPSIMM outcome that effectively discriminates household ambulation from basic community ambulation and from advanced community ambulation-levels of key clinical importance when estimating future prosthetic demands. The overall model performance was modest as it did not discriminate wheelchair from household mobility as effectively. CONCLUSIONS: The AMPREDICT PROsthetics model can assist providers in estimating individual patients' future mobility at the time of prosthetic prescription, thereby aiding in the formulation of appropriate mobility goals, as well as facilitating the prescription of a prosthetic device that is most appropriate for anticipated functional goals.

Early Convalescent Plasma Therapy and Mortality Among US Veterans Hospitalized With Nonsevere COVID-19: An Observational Analysis Emulating a Target Trial.

BACKGROUND: Early convalescent plasma transfusion may reduce mortality in patients with nonsevere coronavirus disease 2019 (COVID-19). METHODS: This study emulates a (hypothetical) target trial using observational data from a cohort of US veterans admitted to a Department of Veterans Affairs (VA) facility between 1 May and 17 November 2020 with nonsevere COVID-19. The intervention was convalescent plasma initiated within 2 days of eligibility. Thirty-day mortality was compared using cumulative incidence curves, risk differences, and hazard ratios estimated from pooled logistic models with inverse probability weighting to adjust for confounding. RESULTS: Of 11 269 eligible person-trials contributed by 4755 patients, 402 trials were assigned to the convalescent plasma group. Forty and 671 deaths occurred within the plasma and nonplasma groups, respectively. The estimated 30-day mortality risk was 6.5% (95% confidence interval [CI], 4.0%-9.7%) in the plasma group and 6.2% (95% CI, 5.6%-7.0%) in the nonplasma group. The associated risk difference was 0.30% (95% CI, -2.30% to 3.60%) and the hazard ratio was 1.04 (95% CI, .64-1.62). CONCLUSIONS: Our target trial emulation estimated no meaningful differences in 30-day mortality between nonsevere COVID-19 patients treated and untreated with convalescent plasma. Clinical Trials Registration. NCT04545047.

Heritability and individuality of the plasma sodium concentration: a twin study in the United States veteran population.

Little is known about the population genetics of water balance. A recent meta-genome-wide association study on plasma sodium concentration identified novel loci of high biological plausibility, yet heritability of the phenotype has never been convincingly shown in European ancestry. The present study linked the Vietnam Era Twin Registry with the Department of Veterans Affairs VistA patient care clinical database. Participants (n = 2,370, 59.6% monozygotic twins and 40.4% dizygotic twins) had a median of seven (interquartile range: 3-14) plasma sodium determinations between October 1999 and March 2017. Heritability of the mean plasma sodium concentration among all twins was 0.41 (95% confidence interval: 0.35-0.46) and 0.49 (95% confidence interval: 0.43-0.54) after exclusion of 514 twins with only a single plasma sodium determination. Heritability among Caucasian (n = 1,958) and African-American (n = 268) twins was 0.41 (95% confidence interval: 0.34-0.47) and 0.36 (95% confidence interval: 0.17-0.52), respectively. Exclusion of data from twins who had been prescribed medications known to impact systemic water balance had no effect. The ability of the present study to newly detect substantial heritability across multiple racial groups was potentially a function of the cohort size and relatedness, exclusion of sodium determinations confounded by elevated plasma glucose and/or reduced glomerular filtration rate, transformation of plasma sodium for the independent osmotic effect of plasma glucose, and use of multiple laboratory determinations per individual over a period of years. Individual-level plasma sodium concentration exhibited longitudinal stability (i.e., individuality); the degree to which individual-level means differed from the population mean was substantial, irrespective of the number of determinations. In aggregate, these data establish the heritability of plasma sodium concentration in European ancestry and corroborate its individuality.

Mortality Associated with Metformin Versus Sulfonylurea Initiation: A Cohort Study of Veterans with Diabetes and Chronic Kidney Disease.

BACKGROUND: For patients with type 2 diabetes and chronic kidney disease (CKD), high-quality evidence about the relative benefits and harms of oral glucose-lowering drugs is limited. OBJECTIVE: To evaluate whether mortality risk differs after the initiation of monotherapy with either metformin or a sulfonylurea in Veterans with type 2 diabetes and CKD. DESIGN: Observational, national cohort study in the Veterans Health Administration (VHA). PARTICIPANTS: Veterans who received care from the VHA for at least 1 year prior to initiating monotherapy treatment for type 2 diabetes with either metformin or a sulfonylurea between 2004 and 2009. MAIN MEASURES: Metformin and sulfonylurea use was assessed from VHA electronic pharmacy records. The CKD-EPI equation was used to estimate glomerular filtration rate (eGFR). The outcome of death from January 1, 2004, through December 31, 2009, was assessed from VHA Vital Status files. KEY RESULTS: Among 175,296 new users of metformin or a sulfonylurea monotherapy, 5121 deaths were observed. In primary analyses adjusted for all measured potential confounding factors, metformin monotherapy was associated with a lower mortality hazard ratio (HR) compared with sulfonylurea monotherapy across all ranges of eGFR evaluated (HR ranging from 0.59 to 0.80). A secondary analysis of mortality risk differences favored metformin across all eGFR ranges; the greatest risk difference was observed in the eGFR category 30-44 mL/min/1.73m2 (12.1 fewer deaths/1000 person-years, 95% CI 5.2-19.0). CONCLUSIONS: Initiation of metformin versus a sulfonylurea among individuals with type 2 diabetes and CKD was associated with a substantial reduction in mortality, in terms of both relative and absolute risk reduction. The largest absolute risk reduction was observed among individuals with moderately-severely reduced eGFR (30-44 mL/min/1.73m2).

Validation of methods for assessing cardiovascular disease using electronic health data in a cohort of Veterans with diabetes.

BACKGROUND: Electronic health data are routinely used to conduct studies of cardiovascular disease in the setting of the Veterans Health Administration (VA). Previous studies have estimated the positive predictive value (PPV) of International Classification of Disease, Ninth Revision (ICD-9) codes for acute myocardial infarction (MI), but the sensitivity of these codes for all true events and the accuracy of coding algorithms for prevalent disease status at baseline are largely unknown. METHODS: We randomly sampled 180 Veterans from the VA Puget Sound Health Care System who initiated diabetes treatment. The full electronic medical record was reviewed to identify prevalent conditions at baseline and acute MI events during follow-up. The accuracy of various coding algorithms was assessed. RESULTS: Algorithms for previous acute events at baseline had high PPV (previous MI: 97%; previous stroke: 81%) but low sensitivity (previous MI: 38%; previous stroke: 52%). Algorithms for chronic conditions at baseline had high PPV (heart failure: 72%; coronary heart disease [CHD]: 85%) and high sensitivity (heart failure: 90%, CHD: 84%). For current smoking status at baseline, ICD-9 codes with pharmacy data had a PPV of 77% and sensitivity of 73%. The coding algorithm for acute MI events during follow-up had high PPV (80%) and sensitivity (89%). CONCLUSIONS: ICD-9 codes for acute MI events during follow-up had high PPV and sensitivity. The sensitivity of ICD-9 codes for previous acute events at baseline was low, but a composite variable for baseline CHD had good accuracy.

Characterizing differences in retinal and choroidal microvasculature and structure in individuals with Huntington's Disease compared to healthy controls: A cross-sectional prospective study.

OBJECTIVE: To characterize retinal and choroidal microvascular and structural changes in patients who are gene positive for mutant huntingtin protein (mHtt) with symptoms of Huntington's Disease (HD). METHODS: This study is a cross-sectional comparison of patients who are gene positive for mHtt and exhibit symptoms of HD, either motor manifest or prodromal (HD group), and cognitively normal individuals without a family history of HD (control group). HD patients were diagnosed by Duke movement disorder neurologists based on the Unified Huntington's Disease Rating Scale (UHDRS). Fovea and optic nerve centered OCT and OCTA images were captured using Zeiss Cirrus HD-5000 with AngioPlex. Outcome metrics included central subfield thickness (CST), peripapillary retinal nerve fiber layer (pRNFL) thickness, ganglion cell-inner plexiform layer (GCIPL) thickness, and choroidal vascularity index (CVI) on OCT, and foveal avascular zone (FAZ) area, vessel density (VD), perfusion density (PD), capillary perfusion density (CPD), and capillary flux index (CFI) on OCTA. Generalized estimating equation (GEE) models were used to account for inter-eye correlation. RESULTS: Forty-four eyes of 23 patients in the HD group and 77 eyes of 39 patients in the control group were analyzed. Average GCIPL thickness and FAZ area were decreased in the HD group compared to controls (p = 0.001, p < 0.001). No other imaging metrics were significantly different between groups. CONCLUSIONS: Patients in the HD group had decreased GCIPL thickness and smaller FAZ area, highlighting the potential use of retinal biomarkers in detecting neurodegenerative changes in HD.

PROClass: The Development and Validation of a Novel Prosthetic Component Sophistication Classification System.

Objective: To develop a lower limb prosthesis (LLP) sophistication classification system that categorizes prosthetic component prescriptions into "basic," "intermediate," and "advanced" and assess its content validity, reliability, and accuracy. Design: Classification development and validation study. Setting: The Veterans Affairs (VA) Corporate Data Warehouse database and National Prosthetics Patient Database were used to identify patients undergoing their first amputation at the transtibial or transfemoral level due to diabetes or peripheral artery disease and to identify the associated codes for each LLP. Participants: An expert panel of 6 nationally recognized certified prosthetists, a national expert in VA prosthetics data and coding, a physical medicine and rehabilitation physician, and an epidemiologist developed an LLP classification system (PROClass) using 30 transfemoral and transtibial lower limb amputees. Main Outcome Measures: The expert panel reviewed 20 consecutive participants meeting study criteria for the development of the PROClass system and a subsequent 30 consecutive cases for assessing the inter- and intra-rater reliability and accuracy. Results: The interrater and intrarater reliability was almost perfect with Gwet's AC1 values ranging from .82 to .96 for both expert panel members and research assistants. The accuracy of the research assistant's classifications to the "criterion standard" was excellent with Gwet's AC1 values ranging between .75 and .92. Conclusions: PROClass is a pragmatic, reliable, and accurate prosthetic classification system with strong face validity that will enable the classification of prosthetic components used for large data set research aimed at evaluating important clinical questions such as the effects of sophistication on patient outcomes.

Intrasession Repeatability of OCT Angiography Parameters in Neurodegenerative Disease.

Purpose: To assess the intrasession repeatability of macular OCT angiography (OCTA) parameters in Alzheimer's disease (AD), mild cognitive impairment (MCI), Parkinson's disease (PD), and normal cognition (NC). Design: Cross sectional study. Subjects: Patients with a clinical diagnosis of AD, PD, MCI, or NC were imaged. Images with poor quality and of those with diabetes mellitus, glaucoma, or vitreoretinal disease were excluded from analysis. Methods Intervention or Testing: All participants were imaged using the Zeiss Cirrus HD-5000 with AngioPlex (Carl Zeiss Meditec, Software Version 11.0.0.29946) and repeat OCTA images were obtained for both eyes. Perfusion density (PFD), vessel density (VD), and Foveal avascular zone (FAZ) area were measured from 3 × 3 mm and 6 × 6 mm OCTA images centered on the fovea using an ETDRS grid overlay. Main Outcome Measures: Intraclass correlation coefficients were used to quantify repeatability of PFD, VD, and FAZ area measurements obtained from imaging. Results: 3 × 3 mm scans of 22 AD, 40 MCI, 21 PD, and 26 NC participants and 6 × 6 mm scans of 29 AD, 44 MCI, 29 PD, and 30 NC participants were analyzed. Repeatability values ranged from 0.64 (0.49-0.82) for 6 × 6 mm PFD in AD participants to 0.87 (0.67-0.92) for 3 × 3 mm PFD in AD participants. No significant differences were observed in repeatability between NC participants and those with neurodegenerative disease. Conclusions: Overall, similar OCTA repeatability was observed between NC participants and those with neurodegeneration. Regardless of diagnostic group, macular OCTA metrics demonstrated moderate to good repeatability. Financial Disclosures: The authors have no proprietary or commercial interest in any materials discussed in this article.

Longitudinal Analysis of Retinal Microvascular and Choroidal Imaging Parameters in Parkinson's Disease Compared with Controls.

Purpose: To quantify rate of change of retinal microvascular and choroidal structural parameters in subjects with Parkinson's disease (PD) compared with controls using OCT and OCT angiography (OCTA). Design: Prospective longitudinal study. Participants: Seventy-four eyes of 40 participants with PD and 149 eyes of 78 control individuals from the Eye Multimodal Imaging in Neurodegenerative Disease database. Methods: Subjects underwent OCT and OCTA imaging at 2 time points approximately 12 months apart. Main Outcome Measures: Imaging parameters included central subfield thickness, ganglion cell-inner plexiform layer (GC-IPL) thickness, peripapillary retinal nerve fiber layer thickness, choroidal vascularity index, superficial capillary plexus perfusion density (PFD), vessel density (VD), and foveal avascular zone area. Results: Participants with PD had greater rate of yearly decrease in GC-IPL (PD = -0.403µm, control = + 0.128 µm; P = 0.01), greater yearly decline in PFD in the 3 × 3 mm ETDRS circle (PD = -0.016, control = + 0.002; P < 0.001) and ring (PD = -0.016, control = + 0.002; P < 0.001); 6 × 6 mm ETDRS circle (PD = -0.021, control = 0.00; P = 0.001), and outer ring (PD = -0.022, control = 0.00; P = 0.001). Participants with PD had greater rate of yearly decline in VD in 3 × 3 mm circle (PD = -0.939/mm, control = + 0.006/mm; P < 0.001) and ring (PD = -0.942/mm, control = + 0.013/mm; P < 0.001); 6 × 6 mm circle (PD = -0.72/mm, control = -0.054/mm; P = 0.006), and outer ring (PD = -0.746/mm, control = -0.054/mm; P = 0.005). When stratified by PD severity based on Hoehn and Yahr stage, faster rates of decline were seen in Hoehn and Yahr stages 3 to 4 in the 3 × 3 mm circle PFD and VD as well as 3 × 3 mm ring VD. Conclusions: Individuals with PD experience more rapid loss of retinal microvasculature quantified on OCTA and more rapid thinning of the GC-IPL than controls. There may be more rapid loss in patients with greater disease severity. Financial Disclosures: The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Association Between Testosterone Treatment and Risk of Incident Cardiovascular Events Among US Male Veterans With Low Testosterone Levels and Multiple Medical Comorbidities.

Background Testosterone treatment is common in men, although risks for major cardiovascular events are unclear. Methods and Results A study was conducted in US male veterans, aged ≥40 years, with low serum testosterone and multiple medical comorbidities and without history of myocardial infarction, stroke, venous thromboembolism, prostate cancer, or testosterone treatment in the prior year. For the primary outcome, we examined if testosterone treatment was associated with a composite cardiovascular outcome (incident myocardial infarction, ischemic stroke, or venous thromboembolism). Testosterone use was modeled as intramuscular or transdermal and as current use, former use, and no use. Current testosterone users were compared with former users to reduce confounding by indication. The cohort consisted of 204 857 men with a mean (SD) age of 60.9 (9.9) years and 4.7 (3.5) chronic medical conditions. During follow-up of 4.3 (2.8) years, 12 645 composite cardiovascular events occurred. In adjusted Cox regression analyses, current use of transdermal testosterone was not associated with risk for the composite cardiovascular outcome (hazard ratio [HR], 0.89; 95% CI, 0.76-1.05) in those without prevalent cardiovascular disease, and in those with prevalent cardiovascular disease was associated with lower risk (HR, 0.80; 95% CI, 0.70-0.91). In similar analyses, current use of intramuscular testosterone was not associated with risk for the composite cardiovascular outcome in men without or with prevalent cardiovascular disease (HR, 0.91; 95% CI, 0.80-1.04; HR, 0.98; 95% CI, 0.89-1.09, respectively). Conclusions In a large cohort of men without a history of myocardial infarction, stroke, or venous thromboembolism, testosterone treatment was not associated with increased risk for incident composite cardiovascular events.

Testosterone treatment and the risk of aggressive prostate cancer in men with low testosterone levels.

PURPOSE: Testosterone treatment of men with low testosterone is common and, although relatively short-term, has raised concern regarding an increased risk of prostate cancer (CaP). We investigated the association between modest-duration testosterone treatment and incident aggressive CaP. MATERIALS AND METHODS: Retrospective inception cohort study of male Veterans aged 40 to 89 years with a laboratory-defined low testosterone measurement from 2002 to 2011 and recent prostate specific antigen (PSA) testing; excluding those with recent testosterone treatment, prostate or breast cancer, high PSA or prior prostate biopsy. Histologically-confirmed incident aggressive prostate cancer or any prostate cancer were the primary and secondary outcomes, respectively. RESULTS: Of the 147,593 men included, 58,617 were treated with testosterone. 313 aggressive CaPs were diagnosed, 190 among untreated men (incidence rate (IR) 0.57 per 1000 person years, 95% CI 0.49-0.65) and 123 among treated men (IR 0.58 per 1000 person years; 95% CI 0.48-0.69). After adjusting for age, race, hospitalization during year prior to cohort entry, geography, BMI, medical comorbidities, repeated testosterone and PSA testing, testosterone treatment was not associated with incident aggressive CaP (HR 0.89; 95% CI 0.70-1.13) or any CaP (HR 0.90; 95% CI 0.81-1.01). No association between cumulative testosterone dose or formulation and CaP was observed. CONCLUSIONS: Among men with low testosterone levels and normal PSA, testosterone treatment was not associated with an increased risk of aggressive or any CaP. The clinical risks and benefits of testosterone treatment can only be fully addressed by large, longer-term randomized controlled trials.

Weight change after initiation of oral hypoglycemic monotherapy for diabetes predicts 5-year mortality: An observational study.

PURPOSE: To investigate whether weight change in the first year after initiating an oral hypoglycemic agent (OHA) for type 2 diabetes treatment is associated with mortality in a national cohort. PROCEDURES: We prospectively followed Veterans Health Administration patients with type 2 diabetes initiating treatment with an OHA and not receiving any other diabetes pharmacotherapy for at least one year. Information on OHAs, weight, co-morbidities, other medications, demographics, and laboratory measurements was obtained from electronic medical records. Logistic regression was used to estimate 5-year mortality odds by weight change during the first year after OHA treatment initiation. FINDINGS: Patients (mean age 65years, 97% male, mean BMI 32.3kg/m2) initiating OHA monotherapy between 2003 and 2008 totaled 145,198 (metformin n=89,111, glipizide n=27,100, glyburide n=25,226, rosiglitazone n=3,761). Most patients (65%) maintained a stable weight (change ⩽5% from baseline) during the first year after OHA initiation. Those losing >5% of baseline weight had a significantly higher odds of death over the subsequent 5-years ranging from 1.64 to 2.13 depending on OHA type. In the metformin group, weight gain >5% of baseline was also associated with higher odds of 5-year mortality. The same results were obtained after conducting three sensitivity analyses that excluded patients for the following reasons: weight loss in the one year prior to OHA initiation, weight change >100lbs, or weight change >50lbs. CONCLUSIONS: Weight loss was associated with higher odds of 5-year mortality among patients initiating an OHA, as was weight gain for metformin only.