Histopathology remains an important source of descriptive biological data in biomedical research. Recent petitions for enhanced reproducibility in scientific studies have elevated the role of tissue ...scoring (semiquantitative and quantitative) in research studies. Effective tissue scoring requires appropriate statistical analysis to help validate the group comparisons and give the pathologist confidence in interpreting the data. Each statistical test is typically founded on underlying assumptions regarding the data. If the underlying assumptions of a statistical test do not match the data, then these tests can lead to increased risk of erroneous interpretations of the data. The choice of appropriate statistical test is influenced by the study’s experimental design and resultant data (eg, paired vs unpaired, normality, number of groups, etc). Here, we identify 3 common pitfalls in the analysis of tissue scores: shopping for significance, overuse of paired t-tests, and misguided analysis of multiple groups. Finally, we encourage pathologists to use the full breadth of resources available to them, such as using statistical software, reading key publications about statistical approaches, and identifying a statistician to serve as a collaborator on the multidisciplinary research team. These collective resources can be helpful in choosing the appropriate statistical test for tissue-scoring data to provide the most valid interpretation for the pathologist.
Full text
Available for:
NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
In 1986, Reactor 4 of the Chernobyl nuclear power plant near Pripyat, Ukraine exploded, releasing highly-radioactive materials into the surrounding environment. Although the physical effects of the ...disaster have been well-documented, a limited amount of research has been conducted on association of the disaster with long-term, clinically-diagnosable mental health disorders. According to the diathesis-stress model, the stress of potential and unknown exposure to radioactive materials and the ensuing changes to ones life or environment due to the disaster might lead those with previous vulnerabilities to fall into a poor state of mental health. Previous studies of this disaster have found elevated symptoms of stress, substance abuse, anxiety, and depression in exposed populations, though often at a subclinical level.
With data from The World Mental Health Composite International Diagnostic Interview, a cross-sectional large mental health survey conducted in Ukraine by the World Health Organization, the mental health of Ukrainians was modeled with multivariable logistic regression techniques to determine if any long-term mental health disorders were association with reporting having lived in the zone affected by the Chernobyl nuclear disaster. Common classes of psychiatric disorders were examined as well as self-report ratings of physical and mental health.
Reporting that one lived in the Chernobyl-affected disaster zone was associated with a higher rate of alcohol disorders among men and higher rates of intermittent explosive disorders among women in a prevalence model. Subjects who lived in the disaster zone also had lower ratings of personal physical and mental health when compared to controls.
Stress resulting from disaster exposure, whether or not such exposure actually occurred or was merely feared, and ensuing changes in life circumstances is associated with increased rates of mental health disorders. Professionals assisting populations that are coping with the consequences of disaster should be aware of possible increases in psychiatric disorders as well as poorer perceptions regarding personal physical and mental health.
While the promise of electronic medical record and biobank data is large, major questions remain about patient privacy, computational hurdles, and data access. One promising area of recent ...development is pre-computing non-individually identifiable summary statistics to be made publicly available for exploration and downstream analysis. In this manuscript we demonstrate how to utilize pre-computed linear association statistics between individual genetic variants and phenotypes to infer genetic relationships between products of phenotypes (e.g., ratios; logical combinations of binary phenotypes using "and" and "or") with customized covariate choices. We propose a method to approximate covariate adjusted linear models for products and logical combinations of phenotypes using only pre-computed summary statistics. We evaluate our method's accuracy through several simulation studies and an application modeling ratios of fatty acids using data from the Framingham Heart Study. These studies show consistent ability to recapitulate analysis results performed on individual level data including maintenance of the Type I error rate, power, and effect size estimates. An implementation of this proposed method is available in the publicly available R package pcsstools.
As biobanks become increasingly popular, access to genotypic and phenotypic data continues to increase in the form of precomputed summary statistics (PCSS). Widespread accessibility of PCSS ...alleviates many issues related to biobank data, including that of data privacy and confidentiality, as well as high computational costs. However, questions remain about how to maximally leverage PCSS for downstream statistical analyses. Here we present a novel method for testing the association of an arbitrary number of single nucleotide variants (SNVs) on a linear combination of phenotypes after adjusting for covariates for common multimarker tests (e.g., SKAT, SKAT‐O) without access to individual patient‐level data (IPD). We validate exact formulas for each method, and demonstrate their accuracy through simulation studies and an application to fatty acid phenotypic data from the Framingham Heart Study.
Full text
Available for:
DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Docosahexaenoic acid (DHA) might help prevent Alzheimer's disease (AD). Red blood cell (RBC) status of DHA is an objective measure of long-term dietary DHA intake. In this prospective observational ...study conducted within the Framingham Offspring Cohort (1490 dementia-free participants aged ≥65 years old), we examined the association of RBC DHA with incident AD, testing for an interaction with
carriership. During the follow-up (median, 7.2 years), 131 cases of AD were documented. In fully adjusted models, risk for incident AD in the highest RBC DHA quintile (Q5) was 49% lower compared with the lowest quintile (Q1) (Hazard ratio HR: 0.51, 95% confidence interval CI: 0.27, 0.96). An increase in RBC DHA from Q1 to Q5 was predicted to provide an estimated 4.7 additional years of life free of AD. We observed an interaction DHA ×
carriership for AD. Borderline statistical significance for a lower risk of AD was observed per standard deviation increase in RBC DHA (HR: 0.71, 95% CI: 0.51, 1.00,
= 0.053) in
carriers, but not in non-carriers (HR: 0.85, 95% CI: 0.65, 1.11,
= 0.240). These findings add to the increasing body of literature suggesting a robust association worth exploring dietary DHA as one strategy to prevent or delay AD.
Undergraduate research experiences (UREs), whether within the context of a mentor-mentee experience or a classroom framework, represent an excellent opportunity to expose students to the independent ...scholarship model. The high impact of undergraduate research has received recent attention in the context of STEM disciplines. Reflecting a 2017 survey of statistics faculty, this article examines the perceived benefits of UREs, as well as barriers to the incorporation of UREs, specifically within the field of statistics. Viewpoints of students, faculty mentors, and institutions are investigated. Further, the article offers several strategies for leveraging characteristics unique to the field of statistics to overcome barriers and thereby provide greater opportunity for undergraduate statistics students to gain research experience.
The association between long-chain omega-3 polyunsaturated fatty acids (n-3 PUFA) and prostate cancer (PC) remains unclear.
We compared incident PC rates as a function of the Omega-3 Index O3I, ...erythrocyte eicosapentaenoic and docosahexaenoic acids (EPA + DHA) in 5607 men (40-80 years of age) seen at the Cooper Clinic who were free of PC at baseline. The average follow-up was 5.1 ± 2.8 years until censoring or reporting a new PC diagnosis. Proportional hazards regression was used to model the linear association between baseline O3I and the age-adjusted time to diagnosis. A meta-analysis of n-3 PUFA biomarker-based studies and incident PC was updated with the present findings.
A total of 116 cases of incident PC were identified. When O3I was examined as a continuous variable, the age-adjusted hazard ratio (HR) (95% CI) was 0.98 (0.89, 1.07;
= 0.25) for each 1% increment in the O3I. The updated meta-analysis with 10 biomarker-based studies found no significant relationship between EPA or DHA levels and risk for PC.
We find no evidence in this study nor in a meta-analysis of similar studies that consuming n-3 PUFA-rich fish or using fish oil supplements affects the risk of PC.
OBJECTIVEThe aim of this study was to evaluate the reliability and validity of the State-Trait Hopelessness Scale (STHS) in patients with heart disease who report moderate to severe state ...hopelessness.
METHODSReliability, concurrent validity, and convergent validity were evaluated for 20 patients.
RESULTSCronbachʼs α for the State and Trait subscales were .81 and .79, respectively. Strong correlations between the State Hopelessness Subscale and Patient Health Questionnaire-9 (r = 0.77, P < .001), State Hope Scale (r = −0.75, P < .001), EQ-5D-5L (r = 0.59, P < .005), and PROMIS-29 domains of depression (P = .72, P < .001), fatigue (P = .61, P < .001), and social roles (P = .45, P = .047) were found. There were strong correlations between the Trait Hopelessness Subscale and Trait Hope Scale (r = −0.58, P < .005), State Hope Scale (r = −0.49, P = .03), and PROMIS-29 fatigue domain (r = 0.54, P = .015).
CONCLUSIONSFindings support the reliability and validity of the STHS for evaluation of hopelessness in patients with heart disease.
To evaluate perceived social support (PSS) in ischemic heart disease (IHD) patients who report hopelessness.
Using a cross-sectional design, 156 patients were screened during their hospitalization ...for moderate to severe state hopelessness. Twenty patients who reported hopelessness during hospitalization and maintained hopelessness one week after hospital discharge were included.
A moderately strong negative correlation was identified between PSS and state hopelessness (r = −0.54, p = .014). PSS was significantly higher in married/partnered patients (26.7 ± 4.85) compared to unmarried/unpartnered patients (18 ± 9.18; t = 2.45, p = .035).
Social support may help reduce hopelessness in vulnerable cardiac patients, especially those who are unpartnered.
•Perceived social support data may add to our understanding of hopelessness.•State hopelessness is negatively associated with perceived social support.•Lower perceived social support was identified in patients not married/partnered.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Lower perceived social support is associated with hopelessness in patients with ischemic heart disease (IHD). Higher perceived social support is associated with higher heart rate variability (HRV) in ...adults following a stressful event, but the relationship between HRV and hopelessness has not been examined in patients with IHD. The purpose of this research was to evaluate the relationships among HRV, perceived social support, and hopelessness in patients with IHD.
Ninety-four participants were enrolled while hospitalized for an IHD event at a large hospital in the United States. Data collection occurred 2 weeks after hospital discharge and included the State-Trait Hopelessness Scale, ENRICHD Social Support Inventory, Patient Health Questionnaire-9, a demographic form, and a short-term HRV measurement taken at rest. Linear models were used to assess associations between variables in unadjusted and adjusted models. Most participants were men (67%), married (75%), and non-Hispanic White (96%) and underwent coronary artery bypass surgery (57%). There were inverse correlations between high frequency HRV and state hopelessness (
=-0.21,
=0.008) and root mean square of successive differences between normal heartbeats HRV and state hopelessness (
=-0.20,
=0.012) after adjusting for important covariates. High frequency and root mean square of successive differences between normal heartbeats did not show evidence of mediating the relationship between perceived social support and hopelessness.
There were significant inverse correlations between parasympathetic measures of HRV and hopelessness. Assessing high frequency and root mean square of successive differences between normal heartbeats during early recovery following an IHD event could provide promising evidence for understanding a possible precursor to hopelessness and targets for future interventions. Registration Information: clinicaltrials.gov. Identifiers: NCT03907891, NCT05003791.
PDF
