54 research outputs found
Taking care of volunteers in a stroke trial: A new assisted-management strategy
Background and purpose: Providing participants with evidence-based care for secondary prevention is an ethical and scientific priority for trials in stroke therapy. The optimal strategy, however, is uncertain. We report the performance of a new approach for delivering preventive care to trial participants. Methods: Participants were enrolled in the Insulin Resistance Intervention after Stroke trial, which examined the insulin sensitiser, pioglitazone versus placebo for prevention of stroke and myocardial infarction after ischaemic stroke or transient ischaemic attack. Preventive care was the responsibility of the participants\u27 personal healthcare providers, but investigators monitored care and provided feedback annually. We studied achievement of 8 prevention goals at baseline and 3 annual visits, with a focus on 3 priority goals: blood pressure \u3c140/90 mm Hg, lowdensity lipoprotein (LDL) cholesterol \u3c2.59 mmol/L and antithrombotic therapy. Results: The proportion of participants achieving the priority goals was highest for antithrombotic use (96-99% in each year) and similar for blood pressure (66-72% in each year) and LDL (68-70% in each year). All 3 priority goals were achieved by 47-52% of participants in any given year. However, only 22% of participants achieved all 3 goals in each year. Conclusions: A strategy of monitoring care and providing feedback was associated with high average yearly achievement of 3 priority secondary prevention goals, but the majority of trial participants did not persist in being at goal over time
Pioglitazone for secondary prevention after ischemic stroke and transient ischemic attack: Rationale and design of the Insulin Resistance Intervention after Stroke Trial
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 \u3e3.0 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
The Comprehensive Post-Acute Stroke Services (COMPASS) study: design and methods for a cluster-randomized pragmatic trial
Background: Patients discharged home after stroke face significant challenges managing residual neurological deficits, secondary prevention, and pre-existing chronic conditions. Post-discharge care is often fragmented leading to increased healthcare costs, readmissions, and sub-optimal utilization of rehabilitation and community services. The COMprehensive Post-Acute Stroke Services (COMPASS) Study is an ongoing cluster-randomized pragmatic trial to assess the effectiveness of a comprehensive, evidence-based, post-acute care model on patient-centered outcomes.
Methods: Forty-one hospitals in North Carolina were randomized (as 40 units) to either implement the COMPASS care model or continue their usual care. The recruitment goal is 6000 patients (3000 per arm). Hospital staff ascertain and enroll patients discharged home with a clinical diagnosis of stroke or transient ischemic attack. Patients discharged from intervention hospitals receive 2-day telephone follow-up; a comprehensive clinic visit within 2 weeks that includes a neurological evaluation, assessments of social and functional determinants of health, and an individualized COMPASS Care PlanTM integrated with a community-specific resource database; and additional follow-up calls at 30 and 60 days post-stroke discharge. This model is consistent with the Centers for Medicare and Medicaid Services transitional care management services provided by physicians or advanced practice providers with support from a nurse to conduct patient assessments and coordinate follow-up services. Patients discharged from usual care hospitals represent the control group and receive the standard of care in place at that hospital. Patient-centered outcomes are collected from telephone surveys administered at 90 days. The primary endpoint is patient-reported functional status as measured by the Stroke Impact Scale 16. Secondary outcomes are: caregiver strain, all-cause readmissions, mortality, healthcare utilization, and medication adherence. The study engages patients, caregivers, and other stakeholders (including policymakers, advocacy groups, payers, and local community coalitions) to advise and support the design, implementation, and sustainability of the COMPASS care model.
Discussion: Given the high societal and economic burden of stroke, identifying a care model to improve recovery, independence, and quality of life is critical for stroke survivors and their caregivers. The pragmatic trial design provides a real-world assessment of the COMPASS care model effectiveness and will facilitate rapid implementation into clinical practice if successful
Indexes and boundaries for "quantitative significance" in statistical decisions.
Boundaries for delta, representing a "quantitatively significant" or "substantively impressive" distinction, have not been established, analogous to the boundary of alpha, usually set at 0.05, for the stochastic or probabilistic component of "statistical significance". To determine what boundaries are being used for the "quantitative" decisions, we reviewed pertinent articles in three general medical journals. For each contrast of two means, contrast of two rates, or correlation coefficient, we noted the investigators' decisions about stochastic significance, stated in P values or confidence intervals, and about quantitative significance, indicated by interpretive comments. The boundaries between impressive and unimpressive distinctions were best formed by a ratio of greater than or equal to 1.2 for the smaller to the larger mean in 546 comparisons, by a standardized increment of greater than or equal to 0.28 and odds ratio of greater than or equal to 2.2 in 392 comparisons of two rates; and by an r value of greater than or equal to 0.32 in 154 correlation coefficients. Additional boundaries were also identified for "substantially" and "highly" significant quantitative distinctions. Although the proposed boundaries should be kept flexible, indexes and boundaries for decisions about "quantitative significance" are particularly useful when a value of delta must be chosen for calculating sample size before the research is done, and when the "statistical significance" of completed research is appraised for its quantitative as well as stochastic components
Adherence to study drug in a stroke prevention trial ?\u3e.
OBJECTIVE: Standards for reporting and analyzing adherence to medical therapy have recently improved due to international consensus efforts. If applied to clinical trial research in patients with stroke, these improvements have the potential to identify when in the sequence of trial operations participants are at risk for non-adherence and opportunities to safeguard adherence.
METHODS: We analyzed three phases of adherence according to the European Society for Patient Adherence, COMpliance, and Persistence (ESPACOMP) Medication Adherence Reporting Guideline (EMERGE) taxonomy in the Insulin Resistance Intervention after Stroke (IRIS) trial: initiation (did patient start drug), implementation (did patient take a drug holiday, defined as temporary cessation lasting ≥14 days), and persistence (did patient prematurely and permanently discontinue drug). IRIS was a randomized, placebo controlled, double-blind trial testing pioglitazone to prevent stroke or myocardial infarction in patients with a recent ischemic stroke or transient ischemic attack. Adherence was classified by self-report. Researchers used coaching algorithms to seek adherence recovery if participants went off drug.
RESULTS: During 2005-2013, 3876 participants were enrolled from 179 sites in seven countries and followed for a mean of 4.8 years. Less than 1% of participants in each group did not initiate study drug. 20% of patients assigned to pioglitazone and 17% assigned to placebo took at least one drug holiday. 36% and 30%, respectively, discontinued the study drug prematurely with or without a prior holiday. The risk for stopping the study drug (temporarily or permanently) in the first year after randomization was twice the risk in each of the subsequent four years. This was true both for patients assigned to active therapy and placebo. More participants assigned to pioglitazone, compared to placebo, took a drug holiday or permanently stopped study drug, but the difference in rates of discontinuation was only evident in year one. In years two through five, rates of discontinuation were similar in the two treatment groups. The difference in rates during year one was the result of adverse effects related to the active study drug, pioglitazone. During the remainder of the trial, the attribution of discontinuations to adverse effects potentially related to pioglitazone was reduced but still higher in those assigned to active drug. Other reasons for discontinuation were similar between treatment groups and were largely unrelated to pharmacodynamic effects of the study drug. Rates of discontinuation varied widely among research sites.
CONCLUSION: Patients in a drug trial for stroke prevention are at greatest risk for premature drug discontinuation early after randomization. Reasons for discontinuation change over time. Variable discontinuation rates among sites suggests that adherence can be improved by using best practices from high-performing sites
Distance from Home to Research Center: A Barrier to In-Person Visits but Not Treatment Adherence in a Stroke Trial.
BACKGROUND AND PURPOSE: Clinical trials often seek to enroll patients from both urban and rural areas to safeguard the generalizability of results. However, maintaining contact with patients who live away from a recruitment site, including rural areas, can be challenging. In this research we examine the effect of distance between patient and study centers on treatment adherence and retention.
METHODS: Secondary analysis of 2,466 participants in the Insulin Resistance Intervention after Stroke trial who were enrolled from research sites in the United States. Driving distance between the zipcodes of patient\u27s reported place of residence and the study center was calculated. Outcome measures were loss to follow-up, completion of annual in-person visits, adherence to preventive therapy, and adherence to study drug in the first 3 years of participation. Logistic regression models were used to adjust for confounders.
RESULTS: Distance from residence to research center was not associated with loss to follow-up, adherence to study drug, or adherence to preventive therapy (p \u3e 0.05 for each). However, patients who lived farther from the research center (\u3e120 miles), compared to patients who lived closer (\u3c60 \u3emiles), were less likely to complete the second annual in-person visit (62 vs. 81%; adjusted OR 0.48; 95% CI 0.31-0.75) and third visit (53 vs. 75%; adjusted OR 0.44; 95% CI 0.29-0.67).
CONCLUSIONS: Distance between patient and study center was an independent predictor of missed in-person visits but not with adherence to study treatment or preventive care
Achievement of Guideline-Recommended Weight Loss Among Patients With Ischemic Stroke and Obesity.
Background and Purpose- The proportion of patients with acute ischemic stroke or transient ischemic attack (TIA) and obesity who successfully achieve goals for weight reduction recommended by major professional organizations is unknown. Methods- We examined the experience of participants in the placebo group of the IRIS trial (Insulin Resistance Intervention after Stroke) with a body mass index ≥30 kg/
Impaired mobility and MRI markers of vascular brain injury: Atherosclerosis Risk in Communities and UK Biobank studies
Background Vascular brain injury (VBI) may be an under-recognised contributor to mobility impairment. We examined associations between MRI VBI biomarkers and impaired mobility.Methods We separately analysed Atherosclerosis Risk in Communities (ARIC) and UK Biobank (UKB) study cohorts. Inclusion criteria were no prevalent clinical stroke, and available brain MRI and balance and gait data. MRI VBI biomarkers were (ARIC: ventricular and white matter hyperintensity (WMH) volumes, non-lacunar and lacunar infarctions, microhaemorrhage; UKB: ventricular, brain and WMH volumes, fractional anisotropy (FA), mean diffusivity (MD), intracellular and isotropic free water volume fractions). Quantitative biomarkers were categorised into tertiles. Mobility impairment outcomes were imbalance and slow walk in ARIC and recent fall and slow walk in UKB. Adjusted multivariable logistic regression analyses were performed.Results We included 1626 ARIC (mean age 76.2 years; 23.4% imbalance, 25.0% slow walk) and 40 098 UKB (mean age 55 years; 15.8% falls, 2.8% slow walk) participants. In ARIC, imbalance associated with four of five VBI measures (all p values<0.05), most strongly with WMH (adjusted OR, aOR 1.64; 95% CI 1.18 to 2.29). Slow walk associated with four of five VBI measures, most strongly with WMH (aOR 2.32; 95% CI 1.66 to 3.24). In UKB, falls associated with all VBI measures except WMH, most strongly with FA (aOR 1.16; 95% CI 1.08 to 1.24). Slow walking associated with WMH, FA and MD, most strongly with FA (aOR 1.57; 95% CI 1.32 to 1.87).Conclusions VBI is associated with mobility impairment in community-dwelling, clinically stroke-free cohorts. Consequences of VBI may extend beyond clinically apparent stroke to include mobility
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