Designing a phase-III time-to-event clinical trial using a modified sample size formula and Poisson-Gamma model for subject accrual that accounts for the lag in site initiation using the PERT distribution.

A priori estimation of sample size and subject accrual in multi-site, time-to-event clinical trials is often challenging. Such trials are powered based on the number of events needed to detect a clinically significant difference. Sample size based on number of events relates to the expected duration of observation time for each subject. Temporal patterns in site initiation and subject enrollment ultimately affect when subjects can be accrued into the study. Lag times are common as the site start-up process optimizes, resulting in delays that may curtail observational follow-up and therefore undermine power. The proposed method introduces a Program Evaluation and Review Technique (PERT) model into the sample size estimation which accounts for the lag in site start-up. Additionally, a PERT model is introduced into a Poisson-Gamma subject accrual model to predict the quantity of study sites needed. The introduction of the PERT model provides greater flexibility in both a priori power assessment and planning the number of sites, as it specifically allows for the inclusion of anticipated delays in site start-up time. This model results in minimal power loss even when PERT distribution inputs are misspecified compared to the traditional assumption of simultaneous start-up for all sites. Together these updated formulations for sample size and subject accrual models offer an improved method for designing a multi-site time-to-event clinical trial that accounts for a flexible site start-up process.

J-shape relation of blood pressure reduction and outcome in acute intracerebral hemorrhage: A pooled analysis of INTERACT2 and ATACH-II individual participant data.

OBJECTIVE: The aim of this study was to better define the shape of association between the degree ("magnitude") of early (< 1 h) reduction in systolic blood pressure (SBP) and outcomes in patients with acute intracerebral hemorrhage (ICH) through pooled analysis of the second Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial (INTERACT2) and second Antihypertensive Treatment of Acute Cerebral Hemorrhage (ATACH-II) datasets. METHODS: Association of the continuous magnitude of SBP reduction described using cubic splines and an ordinal measure of the functional outcome on the modified Rankin scale (mRS) scores at 90 days were analyzed in generalized linear mixed models. Models were adjusted for achieved (mean) and variability (standard deviation, SD) of SBP between 1 and 24 h, various baseline covariates, and trial as a random effect. RESULTS: Among 3796 patients (mean age 63.1 (SD = 13.0) years; female 37.4%), with a mean magnitude (< 1 h) of SBP reduction of 28.5 (22.8) mmHg, those with larger magnitude were more often non-Asian and female, had higher baseline SBP, received multiple blood pressure (BP) lowering agents, and achieved lower SBP levels in 1-24 h. Compared to those patients with no SBP reduction within 1 h (reference), the adjusted odds of unfavorable functional outcome, according to a shift in mRS scores, were lower for SBP reductions up to 60 mmHg with an inflection point between 32 and 46 mmHg, but significantly higher for SBP reductions > 70 mmHg. Similar J-shape associations were evident across various time epochs across 24 h and consistent according to baseline hematoma volume and SBP and history of hypertension. INTERPRETATION: A moderate degree of rapid SBP lowering is associated with improved functional outcome after ICH, but large SBP reductions over 1 h (e.g. from > 200 to target < 140 mmHg) were associated with reduction, or reversal, of any such benefit.

Intraoperative Methylprednisolone and Neurodevelopmental Outcomes in Infants After Cardiac Surgery.

BACKGROUND: Neurodevelopmental impairment is an important consequence for survivors of surgery for critical congenital heart disease. This study sought to determine whether intraoperative methylprednisolone during neonatal cardiac surgery is associated with neurodevelopmental outcomes at 12 months of age and to identify early prognostic variables associated with neurodevelopmental outcomes. METHODS: We performed a planned secondary analysis of a 2-center, double-blind, randomized, placebo-controlled trial of intraoperative methylprednisolone in neonates undergoing cardiac surgery. A brain injury biomarker was measured during surgery. Bayley Scales of Infant and Toddler Development-III (BSID-III) were performed at 12 months of age. Two-sample t tests and generalized linear models were used. RESULTS: There were 129 participants (n = 61 methylprednisolone; n = 68 placebo). There were no significant differences in BSID-III scores and brain injury biomarker levels between treatment groups. Participants who underwent a palliative (versus corrective) procedure had lower mean BSID-III cognitive (101 ± 15 versus 106 ± 14; P = .03) and motor scores (85 ± 18 versus 94 ± 16; P < .01). Longer ventilation time was associated with lower motor scores. Longer cardiac intensive care unit stay was associated with lower cognitive, language, and motor scores. Cardiopulmonary bypass time, aortic cross-clamp time, and deep hypothermic circulatory arrest were not associated with BSID-III scores. CONCLUSIONS: Neurodevelopmental outcomes were not associated with intraoperative methylprednisolone or intraoperative variables. Participants who underwent a neonatal palliative (versus corrective) procedure had longer cardiac intensive care unit stays and worse neurodevelopmental outcomes at 1 year. This work suggests that interventions focused solely on the operative period may not be associated with a long-term neurodevelopmental benefit.

Blood pressure control and clinical outcomes in acute intracerebral haemorrhage: a preplanned pooled analysis of individual participant data.

BACKGROUND: Uncertainty persists over the effects of blood pressure lowering in acute intracerebral haemorrhage. We aimed to combine individual patient-level data from the two largest randomised controlled trials of blood pressure lowering strategies in patients with acute intracerebral haemorrhage to determine the strength of associations between key measures of systolic blood pressure control and safety and efficacy outcomes. METHODS: We did a preplanned pooled analysis of individual patient-level data acquired from the main phase of the Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage Trial (INTERACT2) and the second Antihypertensive Treatment of Acute Cerebral Hemorrhage (ATACH-II) trial. These trials included adult patients aged 19-99 years with spontaneous (non-traumatic) intracerebral haemorrhage and elevated systolic blood pressure, without a clear indication or contraindication to treatment. Patients were excluded if they had a structural cerebral cause for the intracerebral haemorrhage, had a low score (3-5) on the Glasgow Coma Scale, or required immediate neurosurgery. Our primary analysis assessed the independent associations between three post-randomisation systolic blood pressure summary measures-magnitude of reduction in 1 h, mean achieved systolic blood pressure, and variability in systolic blood pressure between 1 h and 24 h-and the primary outcome of functional status, as defined by the distribution of scores on the modified Rankin Scale at 90 days post-randomisation. We analysed the systolic blood pressure measures as continuous variables using generalised linear mixed models, adjusted for baseline covariables and trial. The primary and safety analyses were done in a modified intention-to-treat population, which only included patients with sufficient data on systolic blood pressure. FINDINGS: 3829 patients (mean age 63·1 years [SD 12·9], 1429 [37%] women, and 2490 [65%] Asian ethnicity) were randomly assigned in INTERACT2 and ATACH-II, with a median neurological impairment defined by scores on the National Institutes of Health Stroke Scale of 11 (IQR 6-16) and median time from the onset of symptoms of intracerebral haemorrhage to randomisation of 3·6 h (2·7-4·4). We excluded 20 patients with insufficient or no systolic blood pressure data, and we imputed missing systolic blood pressure data in 23 (1%) of the remaining 3809 patients. Overall, the mean magnitude of early systolic blood pressure reduction was 29 mm Hg (SD 22), and subsequent mean systolic blood pressure achieved was 147 mm Hg (15) and variability in systolic blood pressure was 14 mm Hg (8). Achieved systolic blood pressure was continuously associated with functional status (improvement per 10 mm Hg increase adjusted odds ratio [OR] 0·90 [95% CI 0·87-0·94], p<0·0001). Symptomatic hypotension occurred in 28 (1%) patients, renal serious adverse events occurred in 26 (1%) patients, and cardiac serious adverse events occurred in 99 (3%) patients. INTERPRETATION: Our pooled analyses indicate that achieving early and stable systolic blood pressure seems to be safe and associated with favourable outcomes in patients with acute intracerebral haemorrhage of predominantly mild-to-moderate severity. FUNDING: None.

Statistical analysis plan for pooled individual patient data from two landmark randomized trials (INTERACT2 and ATACH-II) of intensive blood pressure lowering treatment in acute intracerebral hemorrhage.

BACKGROUND: There is persistent uncertainty over the benefits of early intensive systolic blood pressure lowering in acute intracerebral hemorrhage. In particular, over the timing, target, and intensity of systolic blood pressure control for optimum balance of potential benefits (i.e. functional recovery) and risks (e.g. cerebral ischemia). AIMS: To determine associations of early systolic blood pressure lowering parameters and outcomes in patients with a hypertensive response in acute intracerebral hemorrhage. Secondary aims are to identify the modifying effects of patient characteristics and an optimal systolic blood pressure lowering profile. METHODS: Individual participant data pooled analyses of two large, multicenter, randomized controlled trials specifically undertaken to assess the effects of early intensive systolic blood pressure reduction on clinical outcomes in acute intracerebral hemorrhage: the Intensive Blood Pressure in Acute Intracerebral Hemorrhage Trial (INTERACT2) and the Antihypertensive Treatment of Acute Cerebral Hemorrhage (ATACH-II) trial. Combined data will include baseline characteristics; systolic blood pressure in the first 24 h; process of care measures; and key efficacy and safety outcomes. OUTCOMES: The primary outcome is functional recovery, defined by an ordinal distribution of scores on the modified Rankin scale at 90 days post-randomization. Secondary outcomes include various standard binary cut-points for disability-free survival on the modified Rankin scale, and health-related quality of life at 90 days. Safety outcomes include symptomatic hypotension requiring corrective therapy and early neurologic deterioration within 24 h, and deaths, any serious adverse event, and cardiac and renal serious adverse events, within 90 days. DISCUSSION: A pre-determined protocol was developed to facilitate successful collaboration and reduce analysis bias arising from prior knowledge of the findings. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov . Unique identifiers for INTERACT2 (NCT00716079) and ATACH-II (NCT01176565).