Measures of Effect in Stratified Analysis

2017 ◽  
pp. 85-124
Author(s):  
Lars Alfredsson
Keyword(s):  
Stratified Analysis

scholarly journals Airborne Benzo[a]Pyrene may contribute to divergent Pheno-Endotypes in children

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Hyunok Choi ◽  
Miroslav Dostal ◽  
Anna Pastorkova ◽  
Pavel Rossner ◽  
Radim J. Sram
Keyword(s):  
Lung Function ◽  
Atopic Asthma ◽  
T Helper ◽  
T Helper 2 ◽  
Asthmatic Children ◽  
Asthma Outcome ◽  
Unit Increase ◽  
Pyrene Concentration ◽  
Lean Children ◽  
Stratified Analysis

Abstract Background Asthma represents a syndrome for which our understanding of the molecular processes underlying discrete sub-diseases (i.e., endotypes), beyond atopic asthma, is limited. The public health needs to characterize etiology-associated endotype risks is becoming urgent. In particular, the roles of polyaromatic hydrocarbon (PAH), globally distributed combustion by-products, toward the two known endotypes – T helper 2 cell high (Th2) or T helper 2 cell low (non-Th2) – warrants clarification. Objectives To explain ambient B[a]P association with non-atopic asthma (i.e., a proxy of non-Th2 endotype) is markedly different from that with atopic asthma (i.e., a proxy for Th2-high endotype). Methods In a case-control study, we compare the non-atopic as well as atopic asthmatic boys and girls against their respective controls in terms of the ambient Benzo[a]pyrene concentration nearest to their home, plasma 15-Ft2-isoprostane (15-Ft2-isoP), urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG), and lung function deficit. We repeated the analysis for i) dichotomous asthma outcome and ii) multinomial asthma—overweight/obese (OV/OB) combined outcomes. Results The non-atopic asthma cases are associated with a significantly higher median B[a]P (11.16 ng/m3) compared to that in the non-atopic controls (3.83 ng/m3; P-value < 0.001). In asthma-OV/OB stratified analysis, the non-atopic girls with lean and OV/OB asthma are associated with a step-wisely elevated B[a]P (median,11.16 and 18.00 ng/m3, respectively), compared to the non-atopic lean control girls (median, 4.28 ng/m3, P-value < 0.001). In contrast, atopic asthmatic children (2.73 ng/m3) are not associated with a significantly elevated median B[a]P, compared to the atopic control children (2.60 ng/m3; P-value > 0.05). Based on the logistic regression model, on ln-unit increate in B[a]P is associated with 4.7-times greater odds (95% CI, 1.9–11.5, P = 0.001) of asthma among the non-atopic boys. The same unit increase in B[a]P is associated with 44.8-times greater odds (95% CI, 4.7–428.2, P = 0.001) among the non-atopic girls after adjusting for urinary Cotinine, lung function deficit, 15-Ft2-isoP, and 8-oxodG. Conclusions Ambient B[a]P is robustly associated with non-atopic asthma, while it has no clear associations with atopic asthma among lean children. Furthermore, lung function deficit, 15-Ft2-isoP, and 8-oxodG are associated with profound alteration of B[a]P-asthma associations among the non-atopic children.

scholarly journals Age-Stratified Analysis of Diabetes and Pseudophakia Effects on Corneal Endothelial Cell Density

Cornea ◽  
2017 ◽  
Vol 36 (3) ◽  
pp. 367-371 ◽  
Author(s):  
Yicheng Chen ◽  
Sean W. Tsao ◽  
Moonseong Heo ◽  
Patrick K. Gore ◽  
Mitchell D. McCarthy ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Cell Density ◽  
Corneal Endothelial Cell ◽  
Endothelial Cell Density ◽  
Corneal Endothelial Cell Density ◽  
Stratified Analysis

scholarly journals Gender Differences in Uptake, Adherence and Experiences: A Longitudinal, Mixed-Methods Study of a Physical Activity Referral Scheme in Scotland, UK

2021 ◽  
Vol 18 (4) ◽  
pp. 1700
Author(s):  
Coral L. Hanson ◽  
Lis Neubeck ◽  
Richard G. Kyle ◽  
Norrie Brown ◽  
Robyn Gallagher ◽  
...  
Keyword(s):  
Physical Activity ◽  
Gender Differences ◽  
Mixed Methods ◽  
Self Efficacy ◽  
Personal Factors ◽  
Staff Support ◽  
Telephone Interviews ◽  
Efficacy Measures ◽  
Gender Perspectives ◽  
Stratified Analysis

Physical activity referral schemes (PARS) are implemented internationally to increase physical activity (PA), but evidence of effectiveness for population subgroups is equivocal. We examined gender differences for a Scottish PARS. This mixed-methods, concurrent longitudinal study had equal status quantitative and qualitative components. We conducted 348 telephone interviews across three time points (pre-scheme, 12 and 52 weeks). These included validated self-reported PA and exercise self-efficacy measures and open-ended questions about experiences. We recruited 136 participants, of whom 120 completed 12-week and 92 completed 52-week interviews. PARS uptake was 83.8% (114/136), and 12-week adherence for those who started was 43.0% (49/114). Living in less deprived areas was associated with better uptake (p = 0.021) and 12-week adherence (p = 0.020), and with male uptake (p = 0.024) in gender-stratified analysis. Female adherers significantly increased self-reported PA at 12 weeks (p = 0.005) but not 52 weeks. Males significantly increased exercise self-efficacy between baseline and 52 weeks (p = 0.009). Three qualitative themes and eight subthemes developed; gender perspectives, personal factors (health, social circumstances, transport and attendance benefits) and scheme factors (communication, social/staff support, individualisation and age appropriateness). Both genders valued the PARS. To increase uptake, adherence and PA, PARS should ensure timely, personalised communication, individualised, affordable PA and include mechanisms to re-engage those who disengage temporarily.

scholarly journals Inverse association of falciparum positivity with endemic Burkitt lymphoma is robust in analyses adjusting for pre-enrollment malaria in the EMBLEM case-control study

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Sally Peprah ◽  
Martin D. Ogwang ◽  
Patrick Kerchan ◽  
Steven J. Reynolds ◽  
Constance N. Tenge ◽  
...  
Keyword(s):  
Burkitt Lymphoma ◽  
Blood Film ◽  
Malaria Treatment ◽  
Inverse Association ◽  
Recent Infection ◽  
Thick Blood Film ◽  
Study Results ◽  
Community Controls ◽  
Stratified Analysis ◽  
Enrollment Factors

Abstract Background Falciparum and endemic Burkitt lymphoma (eBL) are co-endemic in Africa, but the malaria experience in eBL patients is unknown. A lower prevalence of falciparum has been reported in eBL patients, but those results are anecdotally attributed to pre-enrollment anti-malaria treatment. Methods We studied 677 eBL patients and 2920 community controls aged 0–15 years enrolled in six regions in Uganda, Tanzania, and Kenya during 2010–2016. Falciparum was diagnosed using thick blood film microscopy (TFM) and antigen-capture rapid diagnostic tests (RDTs). Guardians of the children answered a 40-item structured questionnaire about their child’s pre-enrollment lifetime malaria history and treatment, demographics, socioeconomics, animal exposures, fevers, and hospitalizations. We utilized exploratory factor analysis to reduce the 40 questionnaire variables into six factors, including Inpatient malaria and Outpatient malaria factors that were surrogates of pre-enrollment anti-malaria treatment. The six factors accounted for 83–90% of the variance in the questionnaire data. We calculated odds ratios and 95% confidence intervals (OR 95% CI) of association of eBL with falciparum positivity, defined as positive both on TFM or RDTs, or only RDTs (indicative of recent infection) or TFM (indicative of current falciparum infection) versus no infection, using multivariable logistic regression, controlling for group of age (0–2, 3–5, 6–8, 9–11 and 12–15 years), sex, and study site and the afore-mentioned pre-enrollment factors. Results The prevalence of falciparum infection was 25.6% in the eBL cases and 45.7% in community controls (aOR = 0.43, 95% CI: 0.40, 0.47; P < 0.0001). The results were similar for recent falciparum infection (6.9% versus 13.5%, aOR = 0.44, 95% CI: 0.38, 0.50; P < 0.0001) and current falciparum infection (18.7% versus 32.1%, aOR = 0.47, 95% CI: 0.43, 0.51; P < 0.0001). These aORs for any, recent and current falciparum infection did not change when we adjusted for pre-enrollment factors (aORs = 0.46, =0.44, and = 0.51, respectively) were significantly lower in stratified analysis for any infection in children < 5 years (aOR = 0.46; 95% CI: 0.29, 0.75) or ≥ 10 years (aOR = 0.47; 95% CI: 0.32, 0.71). Conclusion Our study results reduce support for pre-enrollment antimalaria treatment as a sole explanation for the observed lower falciparum prevalence in eBL cases and open a space to consider alternative immunology-based hypotheses.

scholarly journals 234 Sleep quality during the coronavirus pandemic in a Brazilian family-based cohort

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A93-A94
Author(s):  
Tamara Taporoski ◽  
Felipe Beijamini ◽  
Francieli Ruiz ◽  
Sabrina Ahmed ◽  
Malcolm von Schantz ◽  
...  
Keyword(s):  
Sleep Quality ◽  
Pittsburgh Sleep Quality Index ◽  
Subjective Sleep Quality ◽  
Full Sample ◽  
Rural Town ◽  
Heart Study ◽  
Longitudinal Comparison ◽  
Family Based ◽  
And Gender ◽  
Stratified Analysis

Abstract Introduction Early in the COVID-19 pandemic, Brazil adopted measures to minimize the spread of the virus, including quarantine orders where people only left home for essential business. This practice could negatively impact sleep by reducing exposure to daylight and physical activity. We examined subjective sleep quality in Baependi, a small rural town in Brazil during the COVID-19 quarantine order. Methods This sample is from the Baependi Heart Study, a family-based cohort of adults. Participants (n=800, 71% women, mean age 51.6±15.6 years) completed the Pittsburgh Sleep Quality Index (PSQI) early in the COVID pandemic (April-May, 2020). They were also asked about their compliance to the quarantine order (yes/no). We compared sleep between quarantined (QT) and not-quarantined individuals (NQT). Longitudinal data was obtained from a subsample of 417 individuals who also completed a pre-COVID PSQI between January, 2010 and September, 2014. Results Individuals compliant with the quarantine had worse sleep quality than non-quarantined individuals [QT PSQI= 6.1 (±3.9), NQT PSQI= 5.0 (±3.5), p&lt;0.01]. Stratified analysis showed that differences in PSQI scores between QT and NQT was greater for women [QT = 6.4 (±4), NQT = 5.2 (±3.7), p&lt;0.01] and older people [QT = 6.6 (±0.1), NQT = 5.5 (±3.3), p=0.02]. Associations were attenuated after adjusting for age and gender. PSQI components demonstrated a higher sleep latency for the QT group in the full sample (p=0.02), women (p&lt;0.01) and young (&lt;50 years, p=0.03). Sleep duration was shorter in the QT young subsample (p=0.03). QT women also reported lower sleep efficiency (p=0.01) and greater use of sleep medication than NQT women (p&lt;0.01). In the longitudinal subsample, PSQI scores were significantly higher during COVID than pre-pandemic [COVID= 5.7 (±3.8), pre-COVID= 5 (±3.3), p&lt;0.01]. The significant change in PSQI was only observed in the QT participants [COVID= 5.9 (±3.7), pre-COVID= 5.2 (±3.4), p&lt;0.01] and not NQT [COVID= 5 (±3.7), pre-COVID= 4.5 (±3), p=0.12. Conclusion Individuals who quarantined during COVID-19 had worse sleep quality than individuals who did not quarantine. Longitudinal comparison demonstrated that participants who quarantined had worse sleep quality during COVID compared to before to the pandemic. Support (if any) NIH 1R01HL141881

scholarly journals Cancer Incidence and Mortality among Petroleum Industry Workers and Residents Living in Oil Producing Communities: A Systematic Review and Meta-Analysis

2021 ◽  
Vol 18 (8) ◽  
pp. 4343
Author(s):  
Felix M. Onyije ◽  
Bayan Hosseini ◽  
Kayo Togawa ◽  
Joachim Schüz ◽  
Ann Olsson
Keyword(s):  
Systematic Review ◽  
Childhood Leukemia ◽  
Meta Analysis ◽  
Random Effect ◽  
Petroleum Industry ◽  
Occupational Exposures ◽  
Increased Risk ◽  
Incidence And Mortality ◽  
Exposed Workers ◽  
Stratified Analysis

Petroleum extraction and refining are major sources of various occupational exposures and of air pollution and may therefore contribute to the global cancer burden. This systematic review and meta-analysis is aimed at evaluating the cancer risk in petroleum-exposed workers and in residents living near petroleum facilities. Relevant studies were identified and retrieved through PubMed and Web of Science databases. Summary effect size (ES) and 95% confidence intervals (CI) were analysed using random effect models, and heterogeneity across studies was assessed (I2). Overall, petroleum industry work was associated with an increased risk of mesothelioma (ES = 2.09, CI: 1.58–2.76), skin melanoma (ES = 1.34, CI: 1.06–1.70 multiple myeloma (ES =1.81, CI: 1.28–2.55), and cancers of the prostate (ES = 1.13, Cl: 1.05–1.22) and urinary bladder (ES = 1.25, CI: 1.09–1.43) and a decreased risk of cancers of the esophagus, stomach, colon, rectum, and pancreas. Offshore petroleum work was associated with an increased risk of lung cancer (ES = 1.20; 95% CI: 1.03–1.39) and leukemia (ES = 1.47; 95% CI: 1.12–1.92) in stratified analysis. Residential proximity to petroleum facilities was associated with childhood leukemia (ES = 1.90, CI: 1.34–2.70). Very few studies examined specific exposures among petroleum industry workers or residents living in oil producing communities. The present review warrants further studies on specific exposure levels and pathways among petroleum-exposed workers and residents living near petroleum facilities.

Inverse Relationship Between Serum Bilirubin and Atherosclerosis in Men: A Meta-Analysis of Published Studies

2003 ◽  
Vol 228 (5) ◽  
pp. 568-571 ◽  
Author(s):  
Ladislav Novotný ◽  
Libor Vítek
Keyword(s):  
Inverse Relationship ◽  
Serum Bilirubin ◽  
Linear Trend ◽  
Meta Analysis ◽  
Negative Relationship ◽  
Epidemiological Studies ◽  
Atherosclerotic Disease ◽  
Categorical Variables ◽  
History Of ◽  
Stratified Analysis

Bilirubin, a major intravascular product of heme catabolism, is a potent antioxidant compound. Numerous studies have been published showing the relationship between serum bilirubin levels and atherosclerosis. In the present investigation all the epidemiological studies available on the effect of serum bilirubin levels and atherosclerotic disease were analyzed. Studies on the epidemiology of atherosclerotic diseases in relation to serum bilirubin levels were searched in the MEDLINE database. Selected studies were subdivided according to serum bilirubin levels and severity of atherosclerotic disease. Because of the limited number of females involved in the studies, only males were included into meta-analysis. Associations for ordered categorical variables (bilirubin and natural history of graded atherosclerosis) were assessed to find correlation and linear trend between analyzed variables. A stratified analysis was conducted to compare risks of clinical outcomes. Eleven relevant studies were used for analysis. A close negative relationship was found between serum bilirubin levels and severity of atherosclerosis (Spearman rank coefficient r = −0.31, P < 0.0001). The linear trend was confirmed in analysis of proportions with x2 values for both disease conditions to be very significant ( P < 0.0001). Unambiguous inverse relationship between serum bilirubin levels and atherosclerosis was demonstrated in this preliminary meta-analytic study. These results indicate the importance of hem oxygenase-related products in the prevention of oxidative stress-mediated diseases.

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