Showing papers by "University of Ottawa published in 2009"

Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement

Abstract: David Moher and colleagues introduce PRISMA, an update of the QUOROM guidelines for reporting systematic reviews and meta-analyses

Preferred reporting items for systematic reviews and meta-analyses: the PRISMA Statement.

Abstract: Systematic reviews and meta-analyses have become increasingly important in health care. Clinicians read them to keep up to date with their field,1,2 and they are often used as a starting point for developing clinical practice guidelines. Granting agencies may require a systematic review to ensure there is justification for further research,3 and some health care journals are moving in this direction.4 As with all research, the value of a systematic review depends on what was done, what was found, and the clarity of reporting. As with other publications, the reporting quality of systematic reviews varies, limiting readers' ability to assess the strengths and weaknesses of those reviews. Several early studies evaluated the quality of review reports. In 1987, Mulrow examined 50 review articles published in 4 leading medical journals in 1985 and 1986 and found that none met all 8 explicit scientific criteria, such as a quality assessment of included studies.5 In 1987, Sacks and colleagues6 evaluated the adequacy of reporting of 83 meta-analyses on 23 characteristics in 6 domains. Reporting was generally poor; between 1 and 14 characteristics were adequately reported (mean = 7.7; standard deviation = 2.7). A 1996 update of this study found little improvement.7 In 1996, to address the suboptimal reporting of meta-analyses, an international group developed a guidance called the QUOROM Statement (QUality Of Reporting Of Meta-analyses), which focused on the reporting of meta-analyses of randomized controlled trials.8 In this article, we summarize a revision of these guidelines, renamed PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses), which have been updated to address several conceptual and practical advances in the science of systematic reviews (Box 1). Box 1 Conceptual issues in the evolution from QUOROM to PRISMA

Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement (Chinese edition)

Abstract: Provide a structured summary including, as applicable, background, objectives, data sources, study eligibility criteria, participants, interventions, study appraisal and synthesis methods, results, limitations, conclusions and implications of key findings, systematic review registration number 2 Structured summary

Microwave Photonics

Abstract: Broadband and low loss capability of photonics has led to an ever-increasing interest in its use for the generation, processing, control and distribution of microwave and millimeter-wave signals for applications such as broadband wireless access networks, sensor networks, radar, satellite communitarians, instrumentation and warfare systems. In this tutorial, techniques developed in the last few years in microwave photonics are reviewed with an emphasis on the systems architectures for photonic generation and processing of microwave signals, photonic true-time delay beamforming, radio-over-fiber systems, and photonic analog-to-digital conversion. Challenges in system implementation for practical applications and new areas of research in microwave photonics are also discussed.

Adaptive co-management for social–ecological complexity

Abstract: Building trust through collaboration, institutional development, and social learning enhances efforts to foster ecosystem management and resolve multi-scale society–environment dilemmas One emerging approach aimed at addressing these dilemmas is adaptive co-management This method draws explicit attention to the learning (experiential and experimental) and collaboration (vertical and horizontal) functions necessary to improve our understanding of, and ability to respond to, complex social–ecological systems Here, we identify and outline the core features of adaptive co-management, which include innovative institutional arrangements and incentives across spatiotemporal scales and levels, learning through complexity and change, monitoring and assessment of interventions, the role of power, and opportunities to link science with policy

Polyploidy and angiosperm diversification

Abstract: Polyploidy has long been recognized as a major force in angiosperm evolution. Recent genomic investigations not only indicate that polyploidy is ubiquitous among angiosperms, but also suggest several ancient genome-doubling events. These include ancient whole genome duplication (WGD) events in basal angiosperm lineages, as well as a proposed paleohexaploid event that may have occurred close to the eudicot divergence. However, there is currently no evidence for WGD in Amborella, the putative sister species to other extant angiosperms. The question is no longer "What proportion of angiosperms are polyploid?", but "How many episodes of polyploidy characterize any given lineage?" New algorithms provide promise that ancestral genomes can be reconstructed for deep divergences (e.g., it may be possible to reconstruct the ancestral eudicot or even the ancestral angiosperm genome). Comparisons of diversification rates suggest that genome doubling may have led to a dramatic increase in species richness in several angiosperm lineages, including Poaceae, Solanaceae, Fabaceae, and Brassicaceae. However, additional genomic studies are needed to pinpoint the exact phylogenetic placement of the ancient polyploidy events within these lineages and to determine when novel genes resulting from polyploidy have enabled adaptive radiations.

B–N compounds for chemical hydrogen storage

Abstract: Hydrogen storage for transportation applications requires high volumetric and gravimetric storage capacity. B-N compounds are well suited as storage materials due to their light weight and propensity for bearing multiple protic (N-H) and hydridic (B-H) hydrogens. This critical review briefly covers the various methods of hydrogen storage, and then concentrates on chemical hydrogen storage using B-N compounds. The simplest B-N compound, ammonia borane (H3NBH3), which has a potential 19.6 wt% hydrogen storage capacity, will be emphasised (127 references).

A Practical Iterative Framework for Qualitative Data Analysis

Abstract: The role of iteration in qualitative data analysis, not as a repetitive mechanical task but as a reflexive process, is key to sparking insight and developing meaning. In this paper the authors presents a simple framework for qualitative data analysis comprising three iterative questions. The authors developed it to analyze qualitative data and to engage with the process of continuous meaning-making and progressive focusing inherent to analysis processes. They briefly present the framework and locate it within a more general discussion on analytic reflexivity. They then highlight its usefulness, particularly for newer researchers, by showing practical applications of the framework in two very different studies.

Extended follow-up and spatial analysis of the American Cancer Society study linking particulate air pollution and mortality.

Abstract: We conducted an extended follow-up and spatial analysis of the American Cancer Society (ACS) Cancer Prevention Study II (CPS-II) cohort in order to further examine associations between long-term exposure to particulate air pollution and mortality in large U.S. cities. The current study sought to clarify outstanding scientific issues that arose from our earlier HEI-sponsored Reanalysis of the original ACS study data (the Particle Epidemiology Reanalysis Project). Specifically, we examined (1) how ecologic covariates at the community and neighborhood levels might confound and modify the air pollution-mortality association; (2) how spatial autocorrelation and multiple levels of data (e.g., individual and neighborhood) can be taken into account within the random effects Cox model; (3) how using land-use regression to refine measurements of air pollution exposure to the within-city (or intra-urban) scale might affect the size and significance of health effects in the Los Angeles and New York City regions; and (4) what exposure time windows may be most critical to the air pollution-mortality association. The 18 years of follow-up (extended from 7 years in the original study [Pope et al. 1995]) included vital status data for the CPS-II cohort (approximately 1.2 million participants) with multiple cause-of-death codes through December 31, 2000 and more recent exposure data from air pollution monitoring sites for the metropolitan areas. In the Nationwide Analysis, the influence of ecologic covariate data (such as education attainment, housing characteristics, and level of income; data obtained from the 1980 U.S. Census; see Ecologic Covariates sidebar on page 14) on the air pollution-mortality association were examined at the Zip Code area (ZCA) scale, the metropolitan statistical area (MSA) scale, and by the difference between each ZCA value and the MSA value (DIFF). In contrast to previous analyses that did not directly include ecologic covariates at the ZCA scale, risk estimates increased when ecologic covariates were included at all scales. The ecologic covariates exerted their greatest effect on mortality from ischemic heart disease (IHD), which was also the health outcome most strongly related with exposure to PM2.5 (particles 2.5 microm or smaller in aerodynamic diameter), sulfate (SO4(2-)), and sulfur dioxide (SO2), and the only outcome significantly associated with exposure to nitrogen dioxide (NO2). When ecologic covariates were simultaneously included at both the MSA and DIFF levels, the hazard ratio (HR) for mortality from IHD associated with PM2.5 exposure (average concentration for 1999-2000) increased by 7.5% and that associated with SO4(2-) exposure (average concentration for 1990) increased by 12.8%. The two covariates found to exert the greatest confounding influence on the PM2.5-mortality association were the percentage of the population with a grade 12 education and the median household income. Also in the Nationwide Analysis, complex spatial patterns in the CPS-II data were explored with an extended random effects Cox model (see Glossary of Statistical Terms at end of report) that is capable of clustering up to two geographic levels of data. Using this model tended to increase the HR estimate for exposure to air pollution and also to inflate the uncertainty in the estimates. Including ecologic covariates decreased the variance of the results at both the MSA and ZCA scales; the largest decrease was in residual variation based on models in which the MSA and DIFF levels of data were included together, which suggests that partitioning the ecologic covariates into between-MSA and within-MSA values more completely captures the sources of variation in the relationship between air pollution, ecologic covariates, and mortality. Intra-Urban Analyses were conducted for the New York City and Los Angeles regions. The results of the Los Angeles spatial analysis, where we found high exposure contrasts within the Los Angeles region, showed that air pollution-mortality risks were nearly 3 times greater than those reported from earlier analyses. This suggests that chronic health effects associated with intra-urban gradients in exposure to PM2.5 may be even larger between ZCAs within an MSA than the associations between MSAs that have been previously reported. However, in the New York City spatial analysis, where we found very little exposure contrast between ZCAs within the New York region, mortality from all causes, cardiopulmonary disease (CPD), and lung cancer was not elevated. A positive association was seen for PM2.5 exposure and IHD, which provides evidence of a specific association with a cause of death that has high biologic plausibility. These results were robust when analyses controlled (1) the 44 individual-level covariates (from the ACS enrollment questionnaire in 1982; see 44 Individual-Level Covariates sidebar on page 22) and (2) spatial clustering using the random effects Cox model. Effects were mildly lower when unemployment at the ZCA scale was included. To examine whether there is a critical exposure time window that is primarily responsible for the increased mortality associated with ambient air pollution, we constructed individual time-dependent exposure profiles for particulate and gaseous air pollutants (PM2.5 and SO2) for a subset of the ACS CPS-II participants for whom residence histories were available. The relevance of the three exposure time windows we considered was gauged using the magnitude of the relative risk (HR) of mortality as well as the Akaike information criterion (AIC), which measures the goodness of fit of the model to the data. For PM2.5, no one exposure time window stood out as demonstrating the greatest HR; nor was there any clear pattern of a trend in HR going from recent to more distant windows or vice versa. Differences in AIC values among the three exposure time windows were also small. The HRs for mortality associated with exposure to SO2 were highest in the most recent time window (1 to 5 years), although none of these HRs were significantly elevated. Identifying critical exposure time windows remains a challenge that warrants further work with other relevant data sets. This study provides additional support toward developing cost-effective air quality management policies and strategies. The epidemiologic results reported here are consistent with those from other population-based studies, which collectively have strongly supported the hypothesis that long-term exposure to PM2.5 increases mortality in the general population. Future research using the extended Cox-Poisson random effects methods, advanced geostatistical modeling techniques, and newer exposure assessment techniques will provide additional insight.

Long-range surface plasmon polaritons

Abstract: Long-range surface plasmon polaritons (LRSPPs) are optical surface waves that propagate along a thin symmetric metal slab or stripe over an appreciable length (centimeters). Vigorous interest in LRSPPs has stimulated a large number of studies over three decades spanning a broad topical landscape. Naturally, a good segment of the literature covers fundamentals such as modal characteristics, excitation, and field enhancement. But a large portion also involves the LRSPP in diverse phenomena, including nonlinear interactions, molecular scattering, fluorescence, surface-enhanced Raman spectroscopy, transmission through opaque metal films and emission extraction, amplification and lasing, surface characterization, metal roughness and islandization, optical interconnects and integrated structures, gratings, thermo-, electro- and magneto-optics, and (bio)chemical sensing. Despite the breadth and depth of the research conducted to date, much remains to be uncovered, and the scope for future investigations is broad. We review the properties of the LRSPP, survey the literature involving this wave, and discuss the prospects for applications. Avenues for further work are suggested.

Specifying and reporting complex behaviour change interventions: the need for a scientific method

Abstract: Complex behaviour change interventions are not well described; when they are described, the terminology used is inconsistent. This constrains scientific replication, and limits the subsequent introduction of successful interventions. Implementation Science is introducing a policy of initially encouraging and subsequently requiring the scientific reporting of complex behaviour change interventions.

STrengthening the REporting of Genetic Association Studies (STREGA): An Extension of the STROBE Statement

Abstract: Making sense of rapidly evolving evidence on genetic associations is crucial to making genuine advances in human genomics and the eventual integration of this information in the practice of medicine and public health. Assessment of the strengths and weaknesses of this evidence, and hence the ability to synthesize it, has been limited by inadequate reporting of results. The STrengthening the REporting of Genetic Association studies (STREGA) initiative builds on the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement and provides additions to 12 of the 22 items on the STROBE checklist. The additions concern population stratification, genotyping errors, modelling haplotype variation, Hardy-Weinberg equilibrium, replication, selection of participants, rationale for choice of genes and variants, treatment effects in studying quantitative traits, statistical methods, relatedness, reporting of descriptive and outcome data, and the volume of data issues that are important to consider in genetic association studies. The STREGA recommendations do not prescribe or dictate how a genetic association study should be designed but seek to enhance the transparency of its reporting, regardless of choices made during design, conduct, or analysis.

Chest Compression Fraction Determines Survival in Patients With Out-of-Hospital Ventricular Fibrillation

Abstract: Background— Quality cardiopulmonary resuscitation contributes to cardiac arrest survival. The proportion of time in which chest compressions are performed in each minute of cardiopulmonary resuscit...

Validation of the 28-joint Disease Activity Score (DAS28) and European League Against Rheumatism response criteria based on C-reactive protein against disease progression in patients with rheumatoid arthritis, and comparison with the DAS28 based on erythrocyte sedimentation rate

Abstract: Objective: To validate and compare the definition of the Disease Activity Score 28 based on C-reactive protein (DAS28 (CRP)) to the definition based on erythrocyte sedimentation rate (ESR). Methods: Data were analysed from two randomised, double-blind, placebo-controlled trials of abatacept of 6-month and 12-month duration in patients with rheumatoid arthritis. European League Against Rheumatism (EULAR) response criteria and the proportion of patients in remission (DAS28 Results: There was general agreement in determining the EULAR responder state using both DAS28 definitions (κ = 0.80, 95% CI 0.76 to 0.83). Overall, there was 82.4% agreement on the EULAR response criteria; when disagreements occurred, the DAS28 (CRP) yielded a better EULAR response more often then DAS28 (ESR) (12.6% vs 4.9%, respectively). There was also agreement in determining remission: κ = 0.69 (95% CI 0.60 to 0.78). Radiographic progression decreased in patients treated with abatacept across EULAR states (from none to moderate to good) based on both definitions. For patients treated with placebo, the trend was not as pronounced, with radiographic scores higher for moderate vs non-responders. For physical function, similar trends were observed across the EULAR states for both DAS28 definitions. Conclusions: The DAS28 (CRP) has been validated against radiographic progression and physical function. While the DAS28 (CRP) yielded a better EULAR response more often than the DAS28 (ESR), the validation profile was similar to the DAS28 (ESR), indicating that both measures are useful for assessing disease activity in patients with rheumatoid arthritis.

Spatial species-richness gradients across scales: a meta-analysis

Abstract: Aim We surveyed the empirical literature to determine how well six diversity hypotheses account for spatial patterns in species richness across varying scales of grain and extent. Location Worldwide. Methods We identified 393 analyses (‘cases') in 297 publications meeting our criteria. These criteria included the requirement that more than one diversity hypothesis was tested for its relationship with species richness. We grouped variables representing the hypotheses into the following ‘correlate types': climate/productivity, environmental heterogeneity, edaphics/nutrients, area, biotic interactions and dispersal/history (colonization limitation or other historical or evolutionary effect). For each case we determined the ‘primary' variable: the one most strongly correlated with taxon richness. We defined ‘primacy' as the proportion of cases in which each correlate type was represented by the primary variable, relative to the number of times it was studied. We tested for differences in both primacy and mean coefficient of determination of the primary variable between the hypotheses and between categories of five grouping variables: grain, extent, taxon (animal vs. plant), habitat medium (land vs. water) and insularity (insular vs. connected). Results Climate/productivity had the highest overall primacy, and environmental heterogeneity and dispersal/history had the lowest. Primacy of climate/productivity was much higher in large-grain and large-extent studies than at smaller scales. It was also higher on land than in water, and much higher in connected systems than in insular ones. For other hypotheses, differences were less pronounced. Throughout, studies on plants and animals showed similar patterns. Coefficients of determination of the primary variables differed little between hypotheses and across the grouping variables, the strongest effects being low means in the smallest grain class and for edaphics/nutrients variables, and a higher mean for water than for land in connected systems but vice versa in insular systems. We highlight areas of data deficiency. Main conclusions Our results support the notion that climate and productivity play an important role in determining species richness at large scales, particularly for non-insular, terrestrial habitats. At smaller extents and grain sizes, the primacy of the different types of correlates appears to differ little from null expectation. In our analysis, dispersal/history is rarely the best correlate of species richness, but this may reflect the difficulty of incorporating historical factors into regression models, and the collinearity between past and current climates. Our findings are consistent with the view that climate determines the capacity for species richness. However, its influence is less evident at smaller spatial scales, probably because (1) studies small in extent tend to sample little climatic range, and (2) at large grains some other influences on richness tend to vary mainly within the sampling unit.

A systematic review of food deserts, 1966-2007.

Abstract: INTRODUCTION: "Food deserts," areas characterized by poor access to healthy and affordable food, may contribute to social and spatial disparities in diet and diet-related health outcomes. However, the extent to which food deserts exist is debated. We review the evidence for the existence of food deserts in socioeconomically disadvantaged areas. METHODS: We conducted a systematic review of primary, quantitative, observational studies, published in English or French, that used geographic or market-basket approaches in high-income countries. The literature search included electronic and hand searches and peer-reviewed and grey literature from 1966 through 2007. We also contacted key researchers to identify other studies. We analyzed the findings and quality of the studies qualitatively. RESULTS: Forty-nine studies in 5 countries met inclusion criteria; the amount and consistency of the evidence varied by country. These studies were a mix of geographic and market-basket approaches, but the methodologic quality of studies and completeness of reported findings were mixed. We found clear evidence for disparities in food access in the United States by income and race. Findings from other high-income countries were sparse and equivocal. CONCLUSION: This review suggests that food deserts exist in the United States, where area-level deprivation compounds individual disadvantage. Evidence for the existence of food deserts in other high-income nations is weak.

A polynuclear lanthanide single-molecule magnet with a record anisotropic barrier.

Abstract: Single-molecule magnets (SMMs) continue to be an attractive research field because of their unique and intriguing properties and potential applications in high-density data storage technologies and molecular spintronics. The anisotropic barrier (U) of an SMM is derived from a combination of an appreciable spin ground state (S) and uniaxial Ising-like magneto-anisotropy (D). The magnet-like behavior can be observed by slow relaxation of the magnetization below the blocking temperature. Since the discovery of SMMs in the early 1990s, this assumption has formed the basis for the understanding of the origin of the anisotropic barrier. However, in recent years the development of novel lanthanide-only SMMs that challenge and defy this theory pose a number of questions: How can slow relaxation of the magnetization be observed in a nonmagnetic state complex? Why are large energy barriers seen for mononuclear lanthanide(III) complexes? To answer such important questions, it is vital to investigate novel SMMs with high magnetoanisotropy for which the influence of the large negative D value could result in higher anisotropic barriers. Clearly lanthanide-based polynuclear systems are an important avenue to explore in the pursuit of SMMs with higher anisotropic barriers, because of the strong spin–orbit coupling commonly observed in 4f systems. However, lanthanide-only SMMs are rare. The majority of reported SMMs have been prepared with transition-metal ions, although the recent application of a mixed transition-metal/ lanthanide strategy also yielded many structurally and magnetically interesting systems. The scarcity of lanthanide-only SMMs results from the difficulty in promoting magnetic interactions between the lanthanide ions. The interactions can, however, be enhanced by overlapping bridging ligand orbitals. In addition, fast quantum tunneling of the magnetization (QTM), which is common for lanthanide systems, generally prevents the isolation of SMMs with high anisotropic energy barriers. Our recent work suggests that dysprosium(III) ions may hold the key to obtaining high-blocking-temperature lanthanide-only SMMs. When an appropriate ligand system is employed, it is possible to exploit the large intrinsic magnetoanisotropy, high spin, and reduced QTM that dysprosium(III) ions offer. Recently, we have focused our attention towards the synthesis of dysprosium(III) cluster complexes with 1,2bis(2-hydroxy-3-methoxybenzylidene) hydrazone (H2bmh) and 3-methoxysalicylaldehyde hydrazone (Hmsh) as chelating agents (see Figure S1 in the Supporting Information). This strategy has proven to be successful and has led to a polynuclear lanthanide SMM with a record anisotropic barrier. Herein, we report the synthesis, structure, and magnetism of a tetranuclear dysprosium(III) SMM that exhibits the largest relaxation barrier seen for any polynuclear SMM to date. A suspension of DyCl3·6H2O and o-vanillin (2:1 ratio) in DMF/CH2Cl2 (1:5 ratio) was treated with 4 equivalents of Et3N. The solution was stirred for 1 minute, and then 4 equivalents of N2H4·H2O was added. The resulting yellow solution yielded rectangular, orange-yellow crystals of the tetranuclear complex [Dy4(m3-OH)2(bmh)2(msh)4Cl2] (1) in 19.1% yield after 2 days. The msh and bmh ligands were formed in situ by the reaction of o-vanillin and hydrazine. The slight excess of hydrazine is essential for the formation of both ligands; when an excess of o-vanillin was used instead, no product was isolated. The basic conditions promote the deprotonation of the ligands and the formation of bridging hydroxide anions. Single-crystal X-ray analysis revealed the centrosymmetric complex 1 (Figure 1), which has a defect-dicubane central core. The four coplanar Dy ions are bridged by two m3-OH ligands displaced above and below (0.922 ) the Dy4 plane with Dy O bond lengths of 2.362(6), 2.302(6), and 2.447(6) andDy O Dy angles of 106.5(2), 107.7(2), and 105.7(2)8, and also by a combination of four phenoxide oxygen atoms [Dy O 2.312(2), 2.298(6), 2.448(6), 2.345(6) ] and two diaza bridging groups [Dy N 2.508(8), 2.564(8) ]. Close inspection of the packing arrangement reveals stacking of the [*] P.-H. Lin, Dr. T. J. Burchell, Dr. M. Murugesu Chemistry Department, University of Ottawa and Centre for Catalysis Research and Innovation D’Iorio Hall, 10 Marie Curie, Ottawa, ON, K1N6N5 (Canada) Fax: (+1)613-562-5170 E-mail: m.murugesu@uottawa.ca Homepage: http://www.science.uottawa.ca/~mmuruges/

Establishment of Broadly Applicable Reaction Conditions for the Palladium-Catalyzed Direct Arylation of Heteroatom-Containing Aromatic Compounds

Abstract: Conditions for the palladium-catalyzed direct arylation of a wide range of heterocycles with aryl bromides are reported. Those conditions employ a stoichiometric ratio of both coupling partners, as well as a substoichiometric quantity of pivalic acid, which results in significantly faster reactions. An evaluation of the influence of the nature of the aryl halide has also been carried out.

A genome-wide meta-analysis identifies 22 loci associated with eight hematological parameters in the HaemGen consortium

Abstract: The number and volume of cells in the blood affect a wide range of disorders including cancer and cardiovascular, metabolic, infectious and immune conditions. We consider here the genetic variation in eight clinically relevant hematological parameters, including hemoglobin levels, red and white blood cell counts and platelet counts and volume. We describe common variants within 22 genetic loci reproducibly associated with these hematological parameters in 13,943 samples from six European population-based studies, including 6 associated with red blood cell parameters, 15 associated with platelet parameters and 1 associated with total white blood cell count. We further identified a long-range haplotype at 12q24 associated with coronary artery disease and myocardial infarction in 9,479 cases and 10,527 controls. We show that this haplotype demonstrates extensive disease pleiotropy, as it contains known risk loci for type 1 diabetes, hypertension and celiac disease and has been spread by a selective sweep specific to European and geographically nearby populations.

H2O at the Phoenix landing site.

Abstract: The Phoenix mission investigated patterned ground and weather in the northern arctic region of Mars for 5 months starting 25 May 2008 (solar longitude between 76.5° and 148°). A shallow ice table was uncovered by the robotic arm in the center and edge of a nearby polygon at depths of 5 to 18 centimeters. In late summer, snowfall and frost blanketed the surface at night; H2O ice and vapor constantly interacted with the soil. The soil was alkaline (pH = 7.7) and contained CaCO3, aqueous minerals, and salts up to several weight percent in the indurated surface soil. Their formation likely required the presence of water.

Randomized Controlled Trial of Resistance or Aerobic Exercise in Men Receiving Radiation Therapy for Prostate Cancer

Abstract: Purpose Radiotherapy for prostate cancer (PCa) may cause unfavorable changes in fatigue, quality of life (QOL), and physical fitness. We report results from the Prostate Cancer Radiotherapy and Exercise Versus Normal Treatment study examining the effects of 24 weeks of resistance or aerobic training versus usual care on fatigue, QOL, physical fitness, body composition, prostate-specific antigen, testosterone, hemoglobin, and lipid levels in men with PCa receiving radiotherapy. Patients and Methods Between 2003 and 2006, we conducted a randomized controlled trial in Ottawa, Canada, where 121 PCa patients initiating radiotherapy with or without androgen deprivation therapy were randomly assigned to usual care (n = 41), resistance (n = 40), or aerobic exercise (n = 40) for 24 weeks. Our primary end point was fatigue assessed by the Functional Assessment of Cancer Therapy–Fatigue scale. Results The follow-up assessment rate for our primary end point of fatigue was 92.6%. Median adherence to prescribed exercis...

Latent Class Growth Modelling: A Tutorial

Abstract: The present work is an introduction to Latent Class Growth Modelling (LCGM). LCGM is a semi‐parametric statistical technique used to analyze longitudinal data. It is used when the data follows a pattern of change in which both the strength and the direction of the relationship between the independent and dependent variables differ across cases. The analysis identifies distinct subgroups of individuals following a distinct pattern of change over age or time on a variable of interest. The aim of the present tutorial is to introduce readers to LCGM and provide a concrete example of how the analysis can be performed using a real‐world data set and the SAS software package with accompanying PROC TRAJ application. The advantages and limitations of this technique are also discussed.