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Background/aimsWhen participants in individually randomized group treatment trials are treated by multiple clinicians or in multiple group treatment sessions throughout the trial, this induces partially nested clusters which can affect the power of a trial. We investigate this issue in the Whole Health Options and Pain Education trial, a three-arm pragmatic, individually randomized clinical trial. We evaluate whether partial clusters due to multiple visits delivered by different clinicians in the Whole Health Team arm and dynamic participant groups due to changing group leaders and/or participants across treatment sessions during treatment delivery in the Primary Care Group Education arm may impact the power of the trial. We also present a Bayesian approach to estimate the intraclass correlation coefficients.MethodsWe present statistical models for each treatment arm of Whole Health Options and Pain Education trial in which power is estimated under different intraclass correlation coefficients and mapping matrices between participants and clinicians or treatment sessions. Power calculations are based on pairwise comparisons. In practice, sample size calculations depend on estimates of the intraclass correlation coefficients at the treatment sessions and clinician levels. To accommodate such complexities, we present a Bayesian framework for the estimation of intraclass correlation coefficients under different participant-to-session and participant-to-clinician mapping scenarios. We simulated continuous outcome data based on various clinical scenarios in Whole Health Options and Pain Education trial using a range of intraclass correlation coefficients and mapping matrices and used Gibbs samplers with conjugate priors to obtain posteriors of the intraclass correlation coefficients under those different scenarios. Posterior means and medians and their biases are calculated for the intraclass correlation coefficients to evaluate the operating characteristics of the Bayesian intraclass correlation coefficient estimators.ResultsPower for Whole Health Team versus Primary Care Group Education is sensitive to the intraclass correlation coefficient in the Whole Health Team arm. In these two arms, an increased number of clinicians, more evenly distributed workload of clinicians, or more homogeneous treatment group sizes leads to increased power. Our simulation study for the intraclass correlation coefficient estimation indicates that the posterior mean intraclass correlation coefficient estimator has less bias when the true intraclass correlation coefficients are large (i.e. 0.10), but when the intraclass correlation coefficient is small (i.e. 0.01), the posterior median intraclass correlation coefficient estimator is less biased.ConclusionKnowledge of intraclass correlation coefficients and the structure of clustering are critical to the design of individually randomized group treatment trials with partially nested clusters. We demonstrate that the intraclass correlation coefficient of the Whole Health Team arm can affect power in the Whole Health Options and Pain Education trial. A Bayesian approach provides a flexible procedure for estimating the intraclass correlation coefficients under complex scenarios. More work is needed to educate the research community about the individually randomized group treatment design and encourage publication of intraclass correlation coefficients to help inform future trial designs.

Given the increasing level and scope of biostatistics expertise needed at academic health centers today, we developed best practices guidelines for biostatistics units to be more effective in providing biostatistical support to their institutions, and in fostering an environment in which unit members can thrive professionally. Our recommendations focus on the key areas of: 1) funding sources and mechanisms; 2) providing and prioritizing access to biostatistical resources; and 3) interacting with investigators. We recommend that the leadership of biostatistics units negotiate for sufficient long-term infrastructure support to ensure stability and continuity of funding for personnel, align project budgets closely with actual level of biostatistical effort, devise and consistently apply strategies for prioritizing and tracking effort on studies, and clearly stipulate with investigators prior to project initiation policies regarding funding, lead time, and authorship.

A study was conducted to evaluate and compare the outcomes in patients following endovascular or open repair of abdominal aortic aneurysm (AAA). Results indicated that perioperative mortality was found to be lower in the case of endovascular as compared to open repair of AAA.

Physical therapy delivered to the homes of elderly people can slow the progression of disability, according to a study of 188 physically frail people 75 years old and older. The therapy focused on improving balance, muscle strength, mobility, and the ability to transfer from one position to another. People with severe frailty probably would not benefit from this type of therapy.

Measures of physical, intellectual and psychological function among elderly hospitalized patients may predict those at high risk of dying. Researchers found that impairment in activities of daily living, dementia, and depression were strongly linked to high mortality rates in 207 hospital patients 70 years or older. The patients could be classified as low, intermediate, or high risk of dying within two years depending on their functional disability on these measures. Two-year mortality rates were about 20% in the low-risk group, 30%-45% in the intermediate-risk group, and 60% in the high-risk group., Context. -- Measures of physical and cognitive function are strong prognostic predictors of hospital outcomes for older persons, but current risk adjustment and burden of illness assessment indices do not include these measures. Objective. -- To evaluate and validate the contribution of functional measures to the ability of 5 standard burden of illness indices (Chadson, Acute Physiology and Chronic Health Evaluation [APACHE] II, Disease Staging, All Patient Refined Diagnosis Related Groups, and a clinician's subjective rating) in predicting 90-day and 2-year mortality among older hospitalized patients. Design. -- Two prospective cohort studies. Setting. -- General medicine service, university teaching hospital. Patients. -- For the development cohort, 207 consecutive patients aged 70 years or older, and for the validation cohort, 318 comparable patents. Main Outcome Measure. -- Death within 90 days and 2 years from the index admission. Results. -- In the development cohort, 29 patients (14%) and 81 patients (39%) died within 90 days and 2 years, respectively. A functional axis was developed using 3 independent risk factors: impairment in instrumental activities of daily living, Mini-Mental State Examination score of less than 20, and shortened Geriatric Depression Scale score of 7 or higher, creating low-, intermediate-, and high-risk groups with associated mortality rates of 20%, 32%, and 60%, respectively (P [less than] .001); the C statistic for the final model was 0.69. The corresponding mortality rates in the validation cohort, in which 59 (19%) and 138 (43%) died within 90 days and 2 years, respectively, were 24%, 45%, and 60% (P [less than] .001); the C statistic for the final model was 0.66. For each burden of illness index, the functional axis contributed significantly to the predictive ability of the model for both 90 days and 2 years. When the functional axis and each burden of illness measure were analyzed in cross-stratified format, mortality rates increased progressively from low-risk to high-risk functional groups within strata of burden of illness indices (double-gradient phenomenon). The contributions of functional and burden of illness measures were substantive and interrelated. Conclusions. -- Functional measures are strong predictors of 90-day and 2-year mortality after hospitalization. Furthermore, these measures contribute substantially to the prognostic ability of 5 burden of illness indices. Optimal risk adjustment for older hospitalized patients should incorporate functional status variables.

An acute episode of sepsis appears to affect mortality rates long after the episode has resolved. Sepsis is a bacterial infection that spreads into the bloodstream. Researchers compared the long-term outcome of 1,505 patients with sepsis and 91,830 patients hospitalized for other conditions (the control group). A model was created based on the control group to estimate how much mortality in patients with sepsis was due to other underlying conditions. Up to 5 years later, patients treated for sepsis had higher mortality rates than predicted by the model. Patients who had had more severe symptoms of sepsis had higher mortality rates., Objective.--To determine the magnitude and duration of the effects of sepsis on survival. Design.--Cohort study. Setting.--The 10 Department of Veterans Affairs Medical Centers of the Systemic Sepsis Cooperative Studies Group, which from 1983 to 1986 conducted the Department of Veterans Affairs Cooperative Study of Corticosteroids in Systemic Sepsis. Patients.--The septic population consisted of 1505 patients with evaluable data from the screening log of the Cooperative Study of Corticosteroids in Systemic Sepsis. All 91 830 nonpsychiatric, noninfected patients discharged from the participating medical centers between October 1, 1984, and September 30, 1985, were included in the control population. Main Outcome Measure.--Death through 8 years after the index hospitalization. Results.--On the basis of a proportional hazards model constructed from the demographic and illness characteristics of the control population, the septic population was at significant risk of dying of nonseptic causes (26% predicted 1-year mortality). In the septic population, the daily risk of dying exceeded predictions from this model for 5 years, and the hazard rate rose with increasing severity of the septic episode throughout the first year (P Conclusions.--Sepsis not only causes deaths acutely, but also increases the risk of death for up to 5 years after the septic episode even after comorbidities are accounted for. The risk of late death during the first year is associated with the severity of the septic episode. JAMA. 1997;277:1058-1063

BACKGROUND: Little is known about the environmental and public health impact of unconventional natural gas extraction activities, including hydraulic fracturing, that occur near residential areas. OBJECTIVES: Our aim was to assess the relationship between household proximity to natural gas wells and reported health symptoms. METHODS: We conducted a hypothesis-generating health symptom survey of 492 persons in 180 randomly selected households with ground-fed wells in an area of active natural gas drilling. Gas well proximity for each household was compared with the prevalence and frequency of reported dermal, respiratory, gastrointestinal, cardiovascular, and neurological symptoms. RESULTS: The number of reported health symptoms per person was higher among residents living < 1 km (mean ± SD, 3.27 ± 3.72) compared with > 2 km from the nearest gas well (mean ± SD, 1.60 ± 2.14; p = 0.0002). In a model that adjusted for age, sex, household education, smoking, awareness of environmental risk, work type, and animals in house, reported skin conditions were more common in households < 1 km compared with > 2 km from the nearest gas well (odds ratio = 4.1; 95% CI: 1.4, 12.3; p = 0.01). Upper respiratory symptoms were also more frequently reported in persons living in households < 1 km from gas wells (39%) compared with households 1-2 km or > 2 km from the nearest well (31 and 18%, respectively) (p = 0.004). No equivalent correlation was found between well proximity and other reported groups of respiratory, neurological, cardiovascular, or gastrointestinal conditions. CONCLUSION: Although these results should be viewed as hypothesis generating, and the population studied was limited to households with a ground-fed water supply, proximity of natural gas wells may be associated with the prevalence of health symptoms including dermal and respiratory conditions in residents living near natural gas extraction activities. Further study of these associations, including the role of specific air and water exposures, is warranted. CITATION: Rabinowitz PM, Slizovskiy IB, Lamers V, Trufan SJ, Holford TR, Dziura JD, Peduzzi PN, Kane MJ, Reif JS, Weiss TR, Stowe MH. 2015. Proximity to natural gas wells and reported health status: results of a household survey in Washington County, Pennsylvania. Environ Health Perspect 123:21-26; http://dx.doi.org/ 10.1289/ehp.1307732, Introduction Unconventional methods of natural gas extraction, including directional drilling and hydraulic fracturing (also known as 'fracking'), have made it possible to reach natural gas reserves in shale deposits thousands [...]

We propose a general multistate transition model. The model is developed for the analysis of repeated episodes of multiple states representing different health status. Transitions among multiple states are modeled jointly using multivariate latent traits with factor loadings. Different types of state transition are described by flexible transition-specific nonparametric baseline intensities. A state-specific latent trait is used to capture individual tendency of the sojourn in the state that cannot be explained by covariates and to account for correlation among repeated sojourns in the same state within an individual. Correlation among sojourns across different states within an individual is accounted for by the correlation between the different latent traits. The factor loadings for a latent trait accommodate the dependence of the transitions to different competing states from a same state. We obtain the semiparametric maximum likelihood estimates through an expectation-maximization (EM) algorithm. The method is illustrated by studying repeated transitions between independence and disability states of activities of daily living (ADL) with death as an absorbing state in a longitudinal aging study. The performance of the estimation procedure is assessed by simulation studies. [ABSTRACT FROM AUTHOR]

Objective: It is critical to identify modifiable factors associated with functional recovery from hip fracture. The authors examined the association between pain intensity and two functional endpoints--instrumental activities of daily living and social activity participation--after hip fracture. Method: A total of 270 cognitively intact, community-dwelling persons older than 65 who underwent surgical hip fracture repair in New Haven. Connecticut, were followed for 12 months. Results: Pain intensity was strongly negatively associated with both instrumental and social functioning (p values < .001). Increases in pain intensity between 6 and 12 months were also associated with concurrent decreases in function (p values < .001). These relationships were partly explained by depressive symptoms and a marker of physical ability--gait speed. Discussion: Interventions to control pain may enhance functional status after hip fracture; however, pain relief must be maintained to sustain recovery. Attention to the complex relationships among pain, depressive symptoms. and physical impairments should inform intervention development. [ABSTRACT FROM AUTHOR]