Chlorthalidone vs. Hydrochlorothiazide for Hypertension-Cardiovascular Events.

BACKGROUND: Whether chlorthalidone is superior to hydrochlorothiazide for preventing major adverse cardiovascular events in patients with hypertension is unclear. METHODS: In a pragmatic trial, we randomly assigned adults 65 years of age or older who were patients in the Department of Veterans Affairs health system and had been receiving hydrochlorothiazide at a daily dose of 25 or 50 mg to continue therapy with hydrochlorothiazide or to switch to chlorthalidone at a daily dose of 12.5 or 25 mg. The primary outcome was a composite of nonfatal myocardial infarction, stroke, heart failure resulting in hospitalization, urgent coronary revascularization for unstable angina, and non-cancer-related death. Safety was also assessed. RESULTS: A total of 13,523 patients underwent randomization. The mean age was 72 years. At baseline, hydrochlorothiazide at a dose of 25 mg per day had been prescribed in 12,781 patients (94.5%). The mean baseline systolic blood pressure in each group was 139 mm Hg. At a median follow-up of 2.4 years, there was little difference in the occurrence of primary-outcome events between the chlorthalidone group (702 patients [10.4%]) and the hydrochlorothiazide group (675 patients [10.0%]) (hazard ratio, 1.04; 95% confidence interval, 0.94 to 1.16; P = 0.45). There were no between-group differences in the occurrence of any of the components of the primary outcome. The incidence of hypokalemia was higher in the chlorthalidone group than in the hydrochlorothiazide group (6.0% vs. 4.4%, P<0.001). CONCLUSIONS: In this large pragmatic trial of thiazide diuretics at doses commonly used in clinical practice, patients who received chlorthalidone did not have a lower occurrence of major cardiovascular outcome events or non-cancer-related deaths than patients who received hydrochlorothiazide. (Funded by the Veterans Affairs Cooperative Studies Program; ClinicalTrials.gov number, NCT02185417.).

Efficacy and Safety of Allopurinol and Febuxostat in Patients With Gout and CKD: Subgroup Analysis of the STOP Gout Trial.

RATIONALE & OBJECTIVE: We conducted a prespecified examination of the efficacy and safety of allopurinol and febuxostat administered using a treat-to-target strategy in trial participants with chronic kidney disease (CKD). STUDY DESIGN: Prespecified sub cohort analysis of a randomized controlled trial. SETTING: & Participants: A sub study of the STOP Gout trial in participants with CKD. CKD was defined as an eGFR 30-59 mL/min/1.73 m2 at baseline. EXPOSURE: Trial participants with CKD and gout and serum urate (sUA) concentration ≥6.8 mg/dL were randomized 1:1 to receive allopurinol or febuxostat. Urate lowering therapy (ULT) was titrated during weeks 0-24 to achieve a goal sUA of <6.0 mg/dl (<5.0 mg/dl with tophi) (Phase 1) and maintained during weeks 25-48 (Phase 2). Gout flare was assessed between weeks 49-72 (Phase 3). OUTCOME: Gout flare between weeks 49-72 (Phase 3) was the primary outcome. Secondary outcomes included sUA goal achievement and ULT dosing at end of Phase 2, and serious adverse events (SAEs). ANALYTICAL APPROACH: Outcomes between treatment groups were compared using logistic regression models for binary outcomes, and Poisson regression for flare rates. Multivariable models were subsequently used, adjusting for factors identified to be imbalanced by treatment arm. RESULTS: 351 of 940 participants (37.3%) had CKD; 277 were assessed for the primary outcome. Fewer patients randomized to allopurinol had a flare during phase 3 (32% vs 45%; p=0.02) despite similar attainment of sUA goal (79% vs. 81%; p=0.6) by the end of Phase 2. Acute kidney injury (AKI) was more common in participants with stage 3 CKD randomized to allopurinol compared to febuxostat. LIMITATIONS: Limited power to assess infrequent safety events, largely male, older population. CONCLUSIONS: Allopurinol and febuxostat are similarly efficacious and well-tolerated in the treatment of gout in people with CKD when used in a treat-to-target regimen.

Strategies for secondary use of real-world clinical and administrative data for outcome ascertainment in pragmatic clinical trials.

BACKGROUND: Pragmatic trials are gaining popularity as a cost-effective way to examine treatment effectiveness and generate timely comparative evidence. Incorporating supplementary real-world data is recommended for robust outcome monitoring. However, detailed operational guidelines are needed to inform effective use and integration of heterogeneous databases. OBJECTIVE: Lessons learned from the Veterans Affairs (VA) Diuretic Comparison Project (DCP) are reviewed, providing adaptable recommendations to capture clinical outcomes from real-world data. METHODS: Non-cancer deaths and major cardiovascular (CV) outcomes were determined using VA, Medicare, and National Death Index (NDI) data. Multiple ascertainment strategies were applied, including claims-based algorithms, natural language processing, and systematic chart review. RESULTS: During a mean follow-up of 2.4 (SD = 1.4) years, 907 CV events were identified within the VA healthcare system. Slight delays (∼1 year) were expected in obtaining Medicare data. An additional 298 patients were found having a CV event outside of the VA in 2016 - 2021, increasing the CV event rate from 3.5 % to 5.7 % (770 of 13,523 randomized). NDI data required âˆ¼2 years waiting period. Such inclusion did not increase the number of deaths identified (all 894 deaths were captured by VA data) but enhanced the accuracy in determining cause of death. CONCLUSION: Our experience supports the recommendation of integrating multiple data sources to improve clinical outcome ascertainment. While this approach is promising, hierarchical data aggregation is required when facing different acquisition timelines, information availability/completeness, coding practice, and system configurations. It may not be feasible to implement comparable applications and solutions to studies conducted under different constraints and practice. The recommendations provide guidance and possible action plans for researchers who are interested in applying cross-source data to ascertain all study outcomes.

Practical issues in pragmatic trials: the implementation of the Diuretic Comparison Project.

BACKGROUND/AIMS: The US Department of Veterans Affairs Point of Care Clinical Trial Program conducts studies that utilize informatics infrastructure to integrate clinical trial protocols into routine care delivery. The Diuretic Comparison Project compared hydrochlorothiazide to chlorthalidone in reduction of major cardiovascular events in subjects with hypertension. Here we describe the cultural, technical, regulatory, and logistical challenges and solutions that enabled successful implementation of this large pragmatic comparative effectiveness Point of Care clinical trial. METHODS: Patients were recruited from 72 Veterans Affairs Healthcare Systems using centralized processes for subject identification, obtaining informed consent, data collection, safety monitoring, site communication, and endpoint identification with minimal perturbation of the local clinical care ecosystem. Patients continued to be managed exclusively by their clinical care providers without protocol specified study visits, treatment recommendations, or data collection extraneous to routine care. Centralized study processes were operationalized through the application layer of the electronic health record via a data coordinating center staffed by clinical nurses, data scientists, and statisticians without site-based research coordinators. Study data was collected from the Veterans Affairs electronic health record supplemented by Medicare and National Death Index data. RESULTS: The study exceeded its enrolled goal (13,523 subjects) and followed subjects for the 5-year study duration. The key determinant of program success was collaboration between researchers, regulators, clinicians, and administrative staff at the site level to customize study procedures to align with local clinical practice. This flexibility was enabled by designation of the study as minimal risk and determination that clinical care providers were not engaged in research by the Veterans Affairs Central Institutional Review Board. Cultural, regulatory, technical, and logistical problems were identified and solved through iterative collaboration between clinical and research entities. Paramount among these problems was customization of the Veterans Affairs electronic health record and data systems to accommodate study procedures. CONCLUSIONS: Leveraging clinical care for large-scale clinical trials is feasible but requires a rethinking of traditional clinical trial design (and regulation) to better meet requirements of clinical care ecosystems. Study designs must accommodate site-specific practice variation to reduce the impact on clinical care. A tradeoff thus exists between designing trial processes tailored to expedite local study implementation versus those to produce a more refined response to the research question. The availability of a uniform and flexible electronic health record in the Department of Veterans Affairs played a major role in the success of the trial. Conducting Point of Care research in other healthcare systems without such research-friendly infrastructure presents a more formidable challenge.

Temperature Changes During Electrophysiology Ablation in Veterans and 1-Year Success Rates: A Retrospective Pilot Analysis.

OBJECTIVES: The authors hypothesized that body core temperature during cardiac arrhythmia procedures in the electrophysiology laboratory declines, and examined the association of changes with the patient or procedural factors. They hypothesized that a greater degree of change negatively affects 1-year ablation success. DESIGN: Retrospective observational study. SETTING: Veteran's Administration Boston Healthcare System. PARTICIPANTS: Consecutive records of veterans undergoing ablation procedures under general anesthesia. INTERVENTIONS: Retrospective data collection and analysis from the electronic medical record. MEASUREMENTS AND MAIN RESULTS: Patient and procedural characteristics were collected from the electronic medical record. Core temperature data included baseline (BT) (following entry to the care process on the day of the procedure), the start (ST) and end of the procedure temperatures (ET), and their differences. The 1-year ablation success was assessed as described elsewhere in the literature. The authors used the paired t-test, linear, and logistic regression for hypothesis testing. Among 107 veterans, core temperatures were significantly lower between BT and ST, BT and ET, and ST and ET (p < 0.001 for all). One-year ablation success was 74.8% (n = 80). In multivariate logistic regression adjusted for age, body mass index and BTs showed a greater degree of change from BT to ET, and the ST-to-ET temperature was significantly associated with lower odds of success (odds ratios of 0.57 and 0.42, respectively; p < 0.05 for both). CONCLUSIONS: Core temperature declines during ablation. Greater temperature decline during general anesthesia was associated with lower 1-year ablation success rates.

Measuring social isolation in older adults: A rapid review informing evidence-based research and practice.

OBJECTIVES: Older adults account for 18.5% of the Canadian population and are at risk of experiencing social isolation, compared to other age groups. Researchers define social isolation as a lack of social contact and relationships, but many social isolation measures do not reflect this definition. The aim of our study is to review the existing measures of social isolation with older adults to recommend evidence-based measures to researchers and practitioners. METHODS: We conducted a rapid review on PsycInfo and PsycTests. We included articles that were written in English or French, were peer-reviewed, used an older adult sample, included a self-report social isolation measure, and reported psychometric information. RESULTS: Following exclusion of ineligible articles, 12 measures were available for analysis. We further categorized the measures into: five most recommended measures, five measures that require further research, and two measures not recommended for use with older adults. CONCLUSIONS: We observed a range of measures with varying suitability to be used with older adults; some were empirically driven but did not have strong psychometric properties, or vice-versa. CLINICAL IMPLICATIONS: It is imperative that interventions aimed to address social isolation in older adults use evidence-based measures to assess progress and report treatment effectiveness.

Creatinine standardization: a key consideration in evaluating whole blood creatinine monitoring systems for CKD screening.

Early detection of CKD using point of care creatinine and eGFR testing improves patient management outcomes. We undertook a field study to evaluate the use of a whole blood creatinine/eGFR device to screen a rural Nicaraguan population to determine the variability between creatinine methods and specimen types. All specimens including capillary and venous dried blood spots (DBS) were tested with an isotope dilution liquid chromatography mass spectrometry (ID-LCMS) gold standard method. This is to our knowledge the first time a capillary whole blood (POC) method has been directly compared to the gold standard IDMS method, through the novel approach of using dried blood spots. Capillary and venous whole blood specimens were obtained and tested directly with the BCMS method, and then, DBS samples were prepared. Venous plasma specimens were tested using three laboratory analyzer creatinine methods. DBS were sent to the site performing ID-LCMS. Control samples were also prepared to assess the stability of shipment and storage of DBS. The ID-LCMS method was aligned using primary and secondary standards. Sixty-six (66) patients participated in the study, and the CKD prevalence rate was 7.8%. While all creatinine methods showed a good correlation to ID-LCMS, there was a positive bias (mean absolute bias range: 0.21-0.63 mg/dL). All methods used were 100% sensitive, but specificity varied from 62.7 to 94.9% with PPV ranging from 25 to 62.5%. A correction factor was used to align the values from each method to ID-LCMS which improved the specificity of each method. This study used a unique DBS approach to align capillary whole blood creatinine to ID-LCMS. To ensure reliability of BCMS for identifying screened patients with CKD, it is important to establish IDMS traceability and alignment prior to undertaking CKD studies.

Using the Bayesian detection of potential risk using inference on blinded safety data (BDRIBS) method to support the decision to refer an event for unblinded evaluation.

In the Sponsor Responsibilities-Safety Reporting Requirements and Safety Assessment for IND and Bioavailability/Bioequivalence Studies: Draft Guidance for Industry (June 2021) the Food and Drug Administration recommends that sponsors develop a Safety Surveillance Plan as a key element of a systematic approach to safety surveillance and describes two possible approaches to assess the aggregate safety data. One approach regularly analyzes unblinded serious adverse events (SAEs) by treatment group. The alternative approach prespecifies estimated background rates for anticipated SAEs in the study population (e.g., myocardial infarctions in an older adult population). If the event rate in the blinded data from the study population exceeds a "trigger rate," then an unblinded analysis by treatment group is conducted. The Bayesian detection of potential risk using inference on blinded safety data (BDRIBS) method has been previously described and offers a quantitative approach for assessing blinded events. In this article we provide a procedural workflow for blinded review of safety data that is consistent with the unblinding "trigger approach" for aggregate safety review. In addition, this publication contextualizes the use of BDRIBS within the broader safety surveillance framework, extends the method to allow for multiple studies, and offers examples of its use in various settings via an R-Shiny application that allows for dynamic visualization and assessment.

Outcomes after Angiography with Sodium Bicarbonate and Acetylcysteine.

BACKGROUND: Intravenous sodium bicarbonate and oral acetylcysteine are widely used to prevent acute kidney injury and associated adverse outcomes after angiography without definitive evidence of their efficacy. METHODS: Using a 2-by-2 factorial design, we randomly assigned 5177 patients at high risk for renal complications who were scheduled for angiography to receive intravenous 1.26% sodium bicarbonate or intravenous 0.9% sodium chloride and 5 days of oral acetylcysteine or oral placebo; of these patients, 4993 were included in the modified intention-to-treat analysis. The primary end point was a composite of death, the need for dialysis, or a persistent increase of at least 50% from baseline in the serum creatinine level at 90 days. Contrast-associated acute kidney injury was a secondary end point. RESULTS: The sponsor stopped the trial after a prespecified interim analysis. There was no interaction between sodium bicarbonate and acetylcysteine with respect to the primary end point (P=0.33). The primary end point occurred in 110 of 2511 patients (4.4%) in the sodium bicarbonate group as compared with 116 of 2482 (4.7%) in the sodium chloride group (odds ratio, 0.93; 95% confidence interval [CI], 0.72 to 1.22; P=0.62) and in 114 of 2495 patients (4.6%) in the acetylcysteine group as compared with 112 of 2498 (4.5%) in the placebo group (odds ratio, 1.02; 95% CI, 0.78 to 1.33; P=0.88). There were no significant between-group differences in the rates of contrast-associated acute kidney injury. CONCLUSIONS: Among patients at high risk for renal complications who were undergoing angiography, there was no benefit of intravenous sodium bicarbonate over intravenous sodium chloride or of oral acetylcysteine over placebo for the prevention of death, need for dialysis, or persistent decline in kidney function at 90 days or for the prevention of contrast-associated acute kidney injury. (Funded by the U.S. Department of Veterans Affairs Office of Research and Development and the National Health and Medical Research Council of Australia; PRESERVE ClinicalTrials.gov number, NCT01467466 .).

Prevalence and Risk Factors for CKD in the General Population of Southwestern Nicaragua.

BACKGROUND: Studies have described Mesoamerican nephropathy among agricultural workers of El Salvador and northwestern Nicaragua. Data on prevalence and risk factors for CKD beyond agricultural workers and in other regions in Nicaragua are sparse. METHODS: We recruited participants from 32 randomly selected communities in the Department of Rivas's ten municipalities in two phases. In phase 1, we screened participants using a field-based capillary creatinine measuring system and collected self-reported information on lifestyle and occupational, exposure, and health histories. Two years later, in phase 2, we enrolled 222 new participants, performing serum creatinine testing in these participants and confirmatory serum creatinine testing in phase 1 participants. RESULTS: We enrolled 1242 of 1397 adults (89%) living in 533 households (median age 41 years; 43% male). We confirmed CKD (eGFR<60 ml/min per 1.73 m2) in 53 of 1227 (4.3%) evaluable participants. In multivariable testing, risk factors for prevalent CKD included age (odds ratio [OR], 1.92; 95% confidence interval [95% CI], 1.89 to 1.96) and self-reported history of hypertension (OR, 1.95; 95% CI, 1.04 to 3.64), diabetes (OR, 2.88; 95% CI, 1.40 to 5.93), or current or past work in the sugarcane industry (OR 2.92; 95% CI, 1.36 to 6.27). CONCLUSIONS: Adjusted CKD prevalence was about 5% with repeat confirmatory testing in southwest Nicaragua, lower than in the northwest region. Risk factors included diabetes, hypertension, and current or prior work in the sugarcane industry but not in other forms of agricultural work. Formal CKD surveillance programs in Nicaragua are needed to assess the overall burden of CKD nationally, with a focus on agricultural workers.

Evaluating the Utility of Coarsened Exact Matching for Pharmacoepidemiology Using Real and Simulated Claims Data.

Coarsened exact matching (CEM) is a matching method proposed as an alternative to other techniques commonly used to control confounding. We compared CEM with 3 techniques that have been used in pharmacoepidemiology: propensity score matching, Mahalanobis distance matching, and fine stratification by propensity score (FS). We evaluated confounding control and effect-estimate precision using insurance claims data from the Pharmaceutical Assistance Contract for the Elderly (1999-2002) and Medicaid Analytic eXtract (2000-2007) databases (United States) and from simulated claims-based cohorts. CEM generally achieved the best covariate balance. However, it often led to high bias and low precision of the risk ratio due to extreme losses in study size and numbers of outcomes (i.e., sparse data bias)-especially with larger covariate sets. FS usually was optimal with respect to bias and precision and always created good covariate balance. Propensity score matching usually performed almost as well as FS, especially with higher index exposure prevalence. The performance of Mahalanobis distance matching was relatively poor. These findings suggest that CEM, although it achieves good covariate balance, might not be optimal for large claims-database studies with rich covariate information; it might be ideal if only a few (<10) strong confounders must be controlled.

A multicenter randomized placebo controlled trial of rifampin to reduce pedal amputations for osteomyelitis in veterans with diabetes (VA INTREPID).

BACKGROUND: The prevalence of diabetes mellitus continues to inexorably rise in the United States and throughout the world. Lower limb amputations are a devastating comorbid complication of diabetes mellitus. Osteomyelitis increases the risk of amputation fourfold and commonly presages death. Antimicrobial therapy for diabetic foot osteomyelitis (DFO) varies greatly, indicating that high quality data are needed to inform clinical decision making. Several small trials have indicated that the addition of rifampin to backbone antimicrobial regimens for osteomyelitis outside the setting of the diabetic foot results in 28 to 42% higher cure rates. METHODS/DESIGN: This is a prospective, randomized, double-blind investigation of the addition of 6 weeks of rifampin, 600 mg daily, vs. matched placebo (riboflavin) to standard-of-care, backbone antimicrobial therapy for DFO. The study population are patients enrolled in Veteran Health Administration (VHA), ages ≥18 and ≤ 89 years with diabetes mellitus and definite or probable osteomyelitis of the foot for whom an extended course of oral or intravenous antibiotics is planned. The primary endpoint is amputation-free survival. The primary hypothesis is that using rifampin as adjunctive therapy will lower the hazard rate compared with the group that does not use rifampin as adjunctive therapy. The primary hypothesis will be tested by means of a two-sided log-rank test with a 5% significance level. The test has 90% power to detect a hazard ratio of 0.67 or lower with a total of 880 study participants followed on average for 1.8 years. DISCUSSION: VA INTREPID will test if a rifampin-adjunctive antibiotic regimen increases amputation-free survival in patients seeking care in the VHA with DFO. A positive finding and its adoption by clinicians would reduce lower extremity amputations and their associated physical and emotional impact and reduce mortality for Veterans and for the general population with diabetic foot osteomyelitis. Given that rifampin-adjunctive regimens are currently employed for therapy for the majority of DFO cases in Europe, and only in a small minority of cases in the United States, the trial results will impact therapeutic decisions, even if the null hypothesis is not rejected. TRIAL REGISTRATION: Registered January 6, 2017 at ClinicalTrials.gov, NCT03012529.

Exploring the impact of safety behaviour use on cognitive, psychophysiological, emotional and behavioural responses during a speech task.

BACKGROUND: There is a debate among researchers and clinicians regarding whether the judicious use of safety behaviours (SBs) during exposure therapy is helpful or detrimental. Central to this debate is the premise that SBs may interfere with one's ability to gather disconfirmatory evidence. AIMS: No study to date has assessed how SB use may impact cognitive mechanisms implicated during an exposure-like task. We investigated multiple cognitive, emotional, psychophysiological and behavioural underpinnings of exposure with and without SBs. METHOD: Speech anxious participants (n = 111) were randomly assigned to deliver an evaluated speech with or without SBs. Self-reported anxiety ratings and psychophysiological arousal measures were recorded at baseline, in anticipation of the speech, and following the speech. Measures of working memory, ability to gather disconfirmatory evidence, speech duration, objective and subjective speech performance, and speech task acceptability were administered. RESULTS: There were no differences between conditions on working memory, self-reported anxiety, psychophysiological arousal, ability to gather disconfirmatory evidence, speech duration, or objective and subjective speech performance. All participants were able to gather disconfirmatory evidence. However, condition did influence willingness to deliver future speeches. Our sample was largely female undergraduate students, and we offered only a small number of specific safety behaviours. CONCLUSIONS: Judicious SB use may not necessarily be detrimental, but clients may believe them to be more helpful than they actually are.

Implications of the Propensity Score Matching Paradox in Pharmacoepidemiology.

Recent work has demonstrated that propensity score matching may lead to increased covariate imbalance, even with the corresponding decrease in propensity score distance between matched units. The extent to which this paradoxical phenomenon might harm causal inference in real epidemiologic studies has not been explored. We evaluated the effect of this phenomenon using insurance claims data from the Pharmaceutical Assistance Contract for the Elderly (1999-2002) and Medicaid Analytic eXtract (2000-2007) databases in the United States. For each data set, we created several 1:1 propensity-score-matched data sets by manipulating the size of the covariate set used to generate propensity scores, the index exposure prevalence in the prematched data set, and the matching algorithm. We matched all index units, then progressively pruned matched sets in order of decreasing propensity score distance, calculating covariate imbalance after each pruning. Although covariate imbalance sometimes increased after progressive pruning of matched sets, the application of commonly used propensity score calipers for defining an acceptable match stopped pruning near the lowest region of the imbalance trend and resulted in an improvement over the imbalance in the prematched data set. Thus, propensity score matching does not appear to induce increased covariate imbalance when standard propensity score calipers are applied in these types of pharmacoepidemiologic studies.

Examining the Utility of the New Raney Vocabulary Measure Alongside the WAIS-III.

Psychometric tests related to vocabulary assessments are, for the most part, restricted in their use by trained professionals and/or are costly. These restrictions limit their use, especially for research purposes. To circumvent these limitations, the Raney Vocabulary Measure was created for assessing vocabulary proficiency, specifically for research purposes. The measure consists of 30 questions where participants were instructed to choose the best definition of each word. The purpose of the study was to examine the utility of the new measure using the highly standardized but protected Wechsler Adult Intelligence Scale. Results from the linear combination of the subscales revealed the significant prediction of the Raney Vocabulary Measure, with the Vocabulary subtest contributing most to the unique variance. These results support that the test examines vocabulary ability. The current results are promising as the test would allow for greater accessibility for researchers who do not have access to restricted psychometric tests.

The Rivas Cohort Study: design and baseline characteristics of a Nicaraguan cohort.

BACKGROUND: A lack of advanced healthcare information systems and validated scientific cohorts in Nicaragua makes it difficult to estimate disease prevalences and other public health statistics. Although there is concern of an "epidemic" of chronic kidney disease (CKD) in this country, statistics regarding its magnitude are derived from only a small number of non-representative studies. Budgetary constraints and the logistical problems of maintaining a study cohort make longitudinal studies difficult. The Rivas Cohort was created to measure disease burden of CKD and other public health priorities in the Department of Rivas, Nicaragua. Using primarily volunteer research students and technologic innovation including GPS, digital photography and point of care biochemical analysis, the ability to establish a longitudinal chronic disease cohort is demonstrated. METHODS: Subjects were recruited from consecutive adjacent households in thirty-two randomly selected communities in the ten municipalities that comprise the Department of Rivas in southern Pacific coastal Nicaragua. The study was conducted in two phases. In the first phase, subjects were enrolled into the cohort and consented for future re-contact. In Phase II, conducted two years later, attempts were made to re-contact 400 of these subjects for additional data collection. Demographic, lifestyle, occupational, exposure and health data was collected for both phases of the study. Blood and urine testing and height, weight and blood pressure measurements were also performed. GPS coordinates of homes were recorded and maps of remote communities created. RESULTS: Of 1397 adults living in 533 households approached for participation a total of 1242 (89 %) were enrolled in the cohort. The median age is 41 years and 43 % are male, demographics in agreement with Nicaraguan census data for the Department of Rivas. During Phase II we attempted to re-contact 400 subjects for a follow-up study of CKD. It was possible to re-contact 84 % of these participants and of those re-contacted 95 % agreed to participate in the follow-up study. Of subjects that were not successfully re-contacted the majority had either moved (32) or were not at home (22) at the time of the study team visits. CONCLUSION: The Rivas Cohort Study enrolled a representative sample of 1242 adults living in the Department of Rivas, Nicaragua. The high re-contact and participation rates at two years suggests that the cohort is suitable for long-term studies and presents opportunities for investigations of disease prevalence, incidence, treatment and other public health matters. GPS coordinates and maps are available for future researchers who wish to use the cohort for additional studies.

Veterans Healthcare Administration providers' attitudes and perceptions regarding pragmatic trials embedded at the point of care.

Background The Veterans Healthcare Administration (VA) is implementing an adaptation of a pragmatic trial program, Point of Care Research (POC-R). The goal of POC-R is to embed research into clinical practice, contributing to a Learning Healthcare System. Provider acceptance and participation in POC-R is essential to its successful implementation. The purpose of this study is to evaluate provider's perceptions and beliefs regarding the POC-R program. Methods Provider focus groups and interviews were conducted at seven VA medical facilities involving 62 providers. A semi-structured script was used that included descriptions of four use cases and targeted questions regarding perceptions, concerns, and attitudes about the POC-R program. Sessions were audio-taped, de-identified, transcribed, and analyzed using systematic qualitative techniques to create response categories and overarching themes. Results The emergent themes were as follows: (1) POC-R is a valuable component of evidence-based practice, providing an opportunity to base clinical practice on more generalizable evidence as well as providing tools to improve local practice; (2) POC-R highlights the tension between the need for autonomy of practice and compliance with protocols; (3) POC-R may create increased time and burden resulting from added research responsibilities; (4) concern about the scientific validity and reliability of results; (5) potential for a negative impact on the provider-patient relationship; and (6) uncertainty regarding what constitutes equipoise, given differences in provider knowledge and preferences. Despite substantive concerns, barriers were generally felt to be solvable. Implementation should include provider education, careful attention to workflow for all arms of the study, inclusion of the entire team, and adequate oversight. Limitations The study design is qualitative with limited implications for causal inference. Participants are from the VA and may not be representative of other clinicians. Conclusion VA providers are supportive of the importance and value of pragmatic trials in general and of POC-R in particular. However, providers have significant concerns regarding the burden, ethics, and evidence regarding equipoise. Results are discussed in terms of implementation recommendations.

Isomorphic categories.

Learning and transfer were investigated for a categorical structure that could be mapped without loss of information from 1 sensory modality to another. The category space was composed of 3 nonoverlapping, linearly separable categories whose members were structured, temporal events. Each stimulus was composed of a sequence of on-off events that varied in duration and number of subevents (complexity). Categories were learned visually, haptically, or auditorily and transferred to the same or another modality. Despite the.isomorphism across modalities, significant differences appeared in both learning and transfer. The visual modality showed an early learning advantage, with information on the transfer test preserved best when encoded visually during learning, worst when encoded haptically, with auditory encoding intermediate. False recognition rates were elevated when categories were learned haptically and transferred to another modality. In general, classification accuracy was highest for the category prototype, with false recognition of the category prototype higher in the cross-modality conditions. The results are discussed in terms of current theories in modality transfer including the difficulties inherent when calculation of similarity must be considered in a cross-modal situation.

Chlorthalidone vs Hydrochlorothiazide for Hypertension Treatment After Myocardial Infarction or Stroke: A Secondary Analysis of a Randomized Clinical Trial.

Importance: Patients with prior myocardial infarction (MI) or stroke have a greater risk of recurrent cardiovascular (CV) events. Objective: To evaluate the association of chlorthalidone (CTD) vs hydrochlorothiazide (HCTZ) with CV outcomes and noncancer deaths in participants with and without prior MI or stroke. Design, Setting, and Participants: This was a prespecified secondary analysis of the Diuretic Comparison Project (DCP), a pragmatic randomized clinical trial conducted within 72 participating Veterans Affairs health care systems from June 2016 to June 2021, in which patients aged 65 years or older with hypertension taking HCTZ at baseline were randomized to continue HCTZ or switch to CTD at pharmacologically comparable doses. This secondary analysis was performed from January 3, 2023, to February 29, 2024. Exposures: Pharmacologically comparable daily dose of HCTZ or CTD and history of MI or stroke. Main Outcomes and Measures: Outcome ascertainment was performed from randomization to the end of the study. The primary outcome consisted of a composite of stroke, MI, urgent coronary revascularization because of unstable angina, acute heart failure hospitalization, or noncancer death. Additional outcomes included achieved blood pressure and hypokalemia (potassium level <3.1 mEq/L; to convert to mmol/L, multiply by 1.0). Results: The DCP randomized 13 523 participants to CTD or HCTZ, with a mean (SD) study duration of 2.4 (1.4) years. At baseline, median age was 72 years (IQR, 69-75 years), and 96.8% were male. Treatment effect was evaluated in subgroups of participants with (n = 1455) and without (n = 12 068) prior MI or stroke at baseline. There was a significant adjusted interaction between treatment group and history of MI or stroke. Participants with prior MI or stroke randomized to CTD had a lower risk of the primary outcome than those receiving HCTZ (105 of 733 [14.3%] vs 140 of 722 [19.4%]; hazard ratio [HR], 0.73; 95% CI, 0.57-0.94; P = .01) compared with participants without prior MI or stroke, among whom incidence of the primary outcome was slightly higher in the CTD arm compared with the HCTZ arm (597 of 6023 [9.9%] vs 535 of 6045 [8.9%]; HR, 1.12; 95% CI, 1.00-1.26; P = .054) (P = .01 for interaction). The incidence of a nadir potassium level less than 3.1 mEq/L and hospitalization for hypokalemia differed among those with and without prior MI or stroke when comparing those randomized to CTD vs HCTZ, with a difference only among those without prior MI or stroke (potassium level <3.1 mEq/L: prior MI or stroke, 43 of 733 [5.9%] vs 37 of 722 [5.1%] [P = .57]; no prior MI or stroke, 292 of 6023 [4.9%] vs 206 of 6045 [3.4%] [P < .001]; hospitalization for hypokalemia: prior MI or stroke, 14 of 733 [1.9%] vs 16 of 722 [2.2%] [P = .72]; no prior MI or stroke: 84 of 6023 [1.4%] vs 57 of 6045 [0.9%] [P = .02]). Conclusions and Relevance: Results of this secondary analysis of the DCP trial suggest that CTD may be associated with reduced major adverse CV events and noncancer deaths in patients with prior MI or stroke compared with HCTZ. Trial Registration: ClinicalTrials.gov Identifier: NCT02185417.