scholarly journals A comprehensive review of the healthy worker effect in occupational epidemiological studies

2020 ◽  
Vol 8 (9) ◽  
pp. 3394
Author(s):  
Fahad Saad Algarni
Keyword(s):  
Reference Group ◽  
Epidemiological Studies ◽  
Epidemiologic Studies ◽  
Mortality And Morbidity ◽  
Healthy Worker Effect ◽  
Confounding Bias ◽  
Comparison Groups ◽  
Consequent Reduction ◽  
Reduction Of Mortality ◽  
The Impact

The reduction of mortality and morbidity rates among occupational cohort studies may be attributed to the presence of the healthy worker effect (HWE). Occupational epidemiologic studies investigating worker’s health are prone to the risk of having the HWE phenomenon and this special form of bias has been debated over the years. Hence, it’s imperative to explore in-depth the magnitude and sources of HWE, and further, elucidate the factors that may affect HWE and strategies reducing HWE. The HWE should be considered as a mixed bias between selection and confounding bias. The validity threats due to the HWE among morbidity studies are the same as the mortality studies. The consequent reduction due to the HWE in the association between the exposure and outcome may lead to underestimating some harmful exposures in the workplace or occupational settings. Healthy hire effect and healthy worker survivor effect are the main sources of HWE. Several factors can increase or decrease the probability of HWE; therefore, the investigators should consider them among future occupational epidemiological studies. Many strategies can help in reducing the impact of HWE, but each strategy has its weaknesses and strengths. Not all strategies can be applied among all occupational epidemiological studies. Mathematical procedures still need further investigations to be validated. HWE is a consequence of inappropriate comparison groups in nature. The usage of the general population as a reference group is not an appropriate choice. By considering the HWE sources and factors and using appropriate strategies, the impact of HWE may be reduced.

scholarly journals Detection of diarrhoea associated rotavirus and co-infection with diarrhoeagenic pathogens in the Littoral region of Cameroon using ELISA, RT-PCR and Luminex xTAG GPP assays

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Rahinatou N. Ghapoutsa ◽  
Maurice Boda ◽  
Rashi Gautam ◽  
Valantine Ngum Ndze ◽  
Akongnwi E. Mugyia ◽  
...  
Keyword(s):  
Demographic Data ◽  
Laboratory Diagnosis ◽  
Epidemiological Studies ◽  
Sub Saharan Africa ◽  
Rt Pcr ◽  
Mortality And Morbidity ◽  
Vaccine Introduction ◽  
Littoral Region ◽  
Rotavirus Vaccines ◽  
The Impact

Abstract Background Despite the global roll-out of rotavirus vaccines (RotaTeq/Rotarix / ROTAVAC/Rotasiil), mortality and morbidity due to group A rotavirus (RVA) remains high in sub-Saharan Africa, causing 104,000 deaths and 600,000 hospitalizations yearly. In Cameroon, Rotarix™ was introduced in March 2014, but, routine laboratory diagnosis of rotavirus infection is not yet a common practice, and vaccine effectiveness studies to determine the impact of vaccine introduction have not been done. Thus, studies examining RVA prevalence post vaccine introduction are needed. The study aim was to determine RVA prevalence in severe diarrhoea cases in Littoral region, Cameroon and investigate the role of other diarrheagenic pathogens in RVA-positive cases. Methods We carried out a study among hospitalized children < 5 years of age, presenting with acute gastroenteritis in selected hospitals of the Littoral region of Cameroon, from May 2015 to April 2016. Diarrheic stool samples and socio-demographic data including immunization and breastfeeding status were collected from these participating children. Samples were screened by ELISA (ProSpecT™ Rotavirus) for detection of RVA antigen and by gel-based RT-PCR for detection of the VP6 gene. Co-infection was assessed by multiplexed molecular detection of diarrheal pathogens using the Luminex xTAG GPP assay. Results The ELISA assay detected RVA antigen in 54.6% (71/130) of specimens, with 45, positive by VP6 RT-PCR and 54, positive using Luminex xTAG GPP. Luminex GPP was able to detect all 45 VP6 RT-PCR positive samples. Co-infections were found in 63.0% (34/54) of Luminex positive RVA infections, with Shigella (35.3%; 12/34) and ETEC (29.4%; 10/34) detected frequently. Of the 71 ELISA positive RVA cases, 57.8% (41/71) were fully vaccinated, receiving two doses of Rotarix. Conclusion This study provides insight on RVA prevalence in Cameroon, which could be useful for post-vaccine epidemiological studies, highlights higher than expected RVA prevalence in vaccinated children hospitalized for diarrhoea and provides the trend of RVA co-infection with other enteric pathogens. RVA genotyping is needed to determine circulating rotavirus genotypes in Cameroon, including those causing disease in vaccinated children.

Patients Who Attend Alone at a First Memory Consultation: Are They a Specific Population,or Is It an Instance of Confounding Bias?

2019 ◽  
Vol 81 (1-2) ◽  
pp. 81-86
Author(s):  
Pierre Koskas ◽  
Mouna Romdhani ◽  
Olivier Drunat
Keyword(s):  
Selection Bias ◽  
Confounding Bias ◽  
Significant Difference ◽  
Comparison Groups ◽  
Methodological Problems ◽  
Group 2 ◽  
The Impact ◽  
First Time ◽  
State Examination ◽  
Group 1

As commonly happens in epidemiological research, none of the reported studies were totally free of methodological problems. Studies have considered the influence of social relationships on dementia, but the mechanisms underlying these associations are not perfectly understood. We look at the possible impact of selection bias. For their first memory consultation, patients may come alone or accompanied by a relative. Our objective is to better understand the impact of this factor by retrospective follow-up of geriatric memory outpatients over several years. All patients over 70 who were referred to Bretonneau Memory Clinic for the first time, between January 2006 and 2018, were included in the study. The patients who came alone formed group 1, the others, whatever type of relative accompanied them, formed group 2. We compared the Mini-Mental State Examination (MMSE) scores of patients; and for all patients who came twice for consultation with at least a 60-day interval, we compared their first MMSE with the MMSE performed at the second consultation. In total, 2,935 patients were included, aged 79.7 ± 8.4 years. Six hundred and twenty-five formed group 1 and 2,310 group 2. We found a significant difference in MMSE scores between the 2 groups of patients; and upon second consultation in group 2, but that difference was minor in group 1. Our finding of a possible confounding factor underlines the complexity of choosing comparison groups in order to minimize selection bias while maintaining clinical relevance.

scholarly journals Back Pain and Heart Failure in Older Adults: Findings From the Health ABC Study

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 203-203
Author(s):  
Jie Chen ◽  
Yiming Zhang ◽  
Eleanor Simonsick ◽  
Angela Starkweather ◽  
Ming-Hui Chen ◽  
...  
Keyword(s):  
Heart Failure ◽  
Older Adults ◽  
Back Pain ◽  
Negative Impact ◽  
Smoking Status ◽  
The Elderly ◽  
Epidemiological Studies ◽  
Negative Influence ◽  
Epidemiologic Studies ◽  
The Impact

Abstract Both back pain and heart failure (HF) have negative influence on all aspects of life. Little is known about the impact of back pain on older adults with HF. We include 1295 older adults who had data collected in the 11th year (2007-2008) of the Health, Aging and Body Composition (Health ABC) study to evaluate the effect of back pain on health status among older adults with and without HF. The participants aged 79-91, 54.8% were female and 34.8% were African American. Among 94 participants with HF, 63 (67.0%) had back pain; among 1201 participants without HF, 649 (54.0%) had back pain. Females reporting back pain had 4.76 (95% CI: 1.83, 12.37) times the odds of having HF compared to those without back pain. Male with back pain, compared to those without back pain, had 1.14 times (95% CI: 0.65, 2.02) the odds of having HF. Depressive symptoms were measured by the Center for Epidemiological Studies-Depression (CES-D) scale. Performance and functions were measured by the Established Populations for Epidemiologic Studies in the Elderly (EPESE) performance score, the Health ABC performance battery score and self-reported difficulty with functional tasks. These symptom and performance measures were significantly associated with both back pain and HF, but not the interaction terms of back pain and HF after adjusting demographic variables including gender, race, smoking status and BMI category. The high incidence and negative impact of back pain highlighted the needs of developing strategies in pain management among older adults with and without HF.

Hemoglobin and All-Cause Mortality: Results from the Baltimore Longitudinal Study of Aging (BLSA).

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2257-2257
Author(s):  
Dan L. Longo ◽  
Alessandro Ble ◽  
Jeffrey E. Metter ◽  
Jack M. Guralnik ◽  
Richard C. Woodman ◽  
...  
Keyword(s):  
Reference Group ◽  
Cox Model ◽  
Smoking Status ◽  
The Elderly ◽  
Epidemiological Studies ◽  
Healthy Population ◽  
Large Cohort Study ◽  
High Risk Populations ◽  
Hb Concentration ◽  
The Impact

Abstract Whether mild-to-moderate hemoglobin (Hb) reduction is associated with increased mortality independent of underlying diseases is still debated. Two epidemiological studies addressing this issue in high risk populations (disabled older women, and persons 85 years or older) reported conflicting results. The BLSA offers the opportunity to investigate this association in an adult generally healthy population. The BLSA is a large cohort study on aging started in 1958. The participants are volunteers living in the Baltimore-Washington area (USA), well educated and self-describing as generally healthy persons. Participants are examined every 1-2 years. In the present analysis, all participants evaluated at least one occasion for Hb were included. Subjects were not excluded for any pre-existing conditions or specific outcomes. Hb levels were measured in 2979 participants recruited from 1958 to 2002 (1793 men and 1186 women, 78.7% Caucasians, age range: 18–96 years). Mean age at initial evaluation was 52.3 (±17.4) years for women and 52.1 (±17.9) for men, and the average time from baseline to death/censoring was 17.6 years for men and 12.4 years for women. Crude mortality rates were 21/1000 person years for men and 9.7/1000 person years for women. After adjusting for age, a U-shaped relationship (obtained fitting a Cox model with a Poisson regression approach according Therneau & Grambsch, 2000) was observed between Hb concentration and mortality with nadir at Hb=12.8g/dL in women and 15.0g in men. In the same model, significant excess of mortality was associated with Hb ≤ 11.2g/dL (95%CI 9.8g/dL–12.3 g/dL) and ≥ 14.0 g/dL (95%CI 13.5g/dL–14.9g/dL) in women, and ≤ 13.4 g/dL (95% CI 12.5g/dL–14.4g/dL) and ≥ 16.2g/dL (95% CI 15.4g/dL–17.2g/dL) in men. After adjusting for demographics, anthropometrics, smoking status, radiation exposure, and co-morbid diseases (heart disease, stroke, pulmonary disease, cancer, diabetes, hypertension), men with Hb ≤ 13.4 g/dL (mean: 12.7 g/dL, SD: 0.6) were at 30% higher risk (RR: 1.31, 95%CI: 1.08–1.58) compared to the reference group (Hb: 13.4–16.2). Accordingly, women with Hb ≤ 11.2 g/dL (mean: 10.2 g/dL, SD: 1.0) showed 100% greater risk compared to the reference group (Hb: 11.2–14.0), however this association was not statistically significant (RR: 2.01, 95% CI: 0.88–4.63). When men with Hb levels <10g/dL and women with <9 g/dL were excluded the results did not substantially change. Our findings showed that in the general population moderately-low Hb levels per se were associated with increased mortality risk. The impact of anemia correction on mortality in the elderly remains to be determined.

scholarly journals Reduction of Management Costs and Avoidance of Air Release of Carcinogens Through a Waste Segregation Program in a Brazilian Medical Institution

2020 ◽  
Vol 8 ◽  
Author(s):  
Fabiane Kellem Oliveira Cesario ◽  
Renata Pereira Fontoura ◽  
Amarildo Henrique da Conceição Junior ◽  
Amanda Gentil Cruz ◽  
Nidah Fawzi Said Nimer ◽  
...  
Keyword(s):  
Waste Management ◽  
Low Cost ◽  
Epidemiologic Studies ◽  
Management Program ◽  
Hospital Waste ◽  
Final Destination ◽  
Carcinogenic Agents ◽  
Consequent Reduction ◽  
Dioxin Exposure ◽  
The Impact

Hospital waste management is a current sustainability challenge. Although not always performed, the most applied approach in current protocols is the proper segregation of waste. The incineration of hospital waste is an significant source of emission of specific toxic particles and gases. We highlighted dioxins, whose representatives have been considered carcinogenic agents since 1994. Several experimental and epidemiologic studies have shown greater cancer morbidity and mortality associated with dioxin exposure. In the present study, we presented the impact of a hospital waste management program implemented in an oncology institution based on proper segregation and consequent reduction of incinerated mass. Data were collected for 8 years and the waste was separated into five categories: infectious (A4), chemical (B), recyclable (DR), non-recyclable (DNR), and sharps (E). The classes addressed to incineration were A4, B, and E. A team education starting from the admission process and with a continued education program was essential for a successfully implemented program. We achieved a 66% saving of waste from incineration, equivalent to 76 tons, of which 71.9 tons corresponded to recyclable waste. If the waste separation protocol was not implemented, the biohazardous and chemical material would contaminate the rest of the residues, making incineration as a final destination mandatory for all the waste. This scenario would result in significantly more dioxins release and a 64% higher cost of waste management. This low-cost implementation measure was effective in the cost reduction of waste management and minimization of air release of human carcinogens.

scholarly journals The Impact of Epidemiology on Fertility and Prenatal Care During the COVID-19 Pandemic

2021 ◽  
Author(s):  
Jodie Dionne-Odom ◽  
Sigal Klipstein
Keyword(s):  
Reproductive Medicine ◽  
Clinical Decision Making ◽  
Virus Transmission ◽  
Clinical Decision ◽  
Epidemiological Studies ◽  
Epidemiologic Studies ◽  
Patient Counseling ◽  
Pregnancy And Postpartum ◽  
Pregnancy And Lactation ◽  
The Impact

Abstract The emergence of the novel coronavirus disease 2019 (COVID-19) presented the field of reproductive medicine with many challenges due to an absence of data to guide clinical decision-making and inform patient counseling and management in the early days of the pandemic. Epidemiological studies rapidly filled key gaps in our understanding of the susceptibility of reproductive-aged women to the virus, transmission dynamics during pregnancy and lactation, and the effect of infection during the prenatal, pregnancy, and postpartum periods. This data guided the development of clinical guidelines written by the American Society for Reproductive Medicine as patients and clinicians navigated reproductive decisions during a time of uncertainty. We present a review of epidemiologic studies published between March and December 2020 that have directly informed prenatal and fertility care during the COVID-19 pandemic. Despite a significant increase in our knowledge base over the past year, many questions remain about the impact of COVID-19 on conception, pregnancy, fetal development, and lactation. In the future, a commitment toward inclusion of pregnant persons and those attempting pregnancy in the design of observational and interventional trials is necessary to gain earlier insights about outcomes and assist providers and patients in making data-driven decisions.

Targeting High-Risk Older Adults into Exercise Programs for Disability Prevention

2003 ◽  
Vol 11 (2) ◽  
pp. 219-228 ◽  
Author(s):  
Jack M. Guralnik ◽  
Suzanne Leveille ◽  
Stefano Volpato ◽  
Marcia S. Marx ◽  
Jiska Cohen-Mansfield
Keyword(s):  
Older Adults ◽  
Functional Limitations ◽  
Exercise Program ◽  
Health Impact ◽  
Epidemiological Studies ◽  
Epidemiologic Studies ◽  
Community Dwelling ◽  
Disability Prevention ◽  
Exercise Interventions ◽  
The Impact

Epidemiological studies have demonstrated that, using objective performance measures of physical functioning, disability risk can be predicted in nondisabled older adults. This makes it possible to recruit a nondisabled but at-risk population for clinical trials of disability prevention. Successful disability prevention in this population, for example through an exercise program, would have a major public health impact. To enhance the development of exercise interventions in this group it would be valuable to have additional information not available from existing epidemiologic studies. This report examines the evidence that functional limitations preceding disability can be identified in a community-dwelling population and that it is feasible to recruit these people into studies. It introduces a series of articles examining the characteristics of this population: motivators and barriers to exercise, exercise habits and preferences, the impact of positive and negative affect, and the impact of pain and functional limitations on attitudes toward exercise.

Key Aspects of Assessing Effectiveness and Efficiency of Implementation of the Federal Clean Air Project on the Example of the Comprehensive Emission Reduction Action Plan in Nizhny Tagil

2020 ◽  
pp. 48-60
Author(s):  
SV Yarushin ◽  
DV Kuzmin ◽  
AA Shevchik ◽  
TM Tsepilova ◽  
VB Gurvich ◽  
...  
Keyword(s):  
Emission Reduction ◽  
Action Plan ◽  
Local Population ◽  
Ambient Air ◽  
Ambient Air Pollution ◽  
Mortality And Morbidity ◽  
Industrial Enterprises ◽  
Clean Air ◽  
Effectiveness And Efficiency ◽  
The Impact

Introduction: Key issues of assessing effectiveness and economic efficiency of implementing the Federal Clean Air Project by public health criteria are considered based on the example of the Comprehensive Emission Reduction Action Plan realized in the city of Nizhny Tagil, Sverdlovsk Region. Materials and methods: We elaborated method approaches and reviewed practical aspects of evaluating measures taken in 2018–2019 at key urban industrial enterprises accounting for 95 % of stationary source emissions. Results: Summary calculations of ambient air pollution and carcinogenic and non-carcinogenic inhalation health risks including residual risks, evaluation of the impact of air quality on urban mortality and morbidity rates, economic assessment of prevented morbidity and premature mortality cases have enabled us not only to estimate health effects but also to develop guidelines for development and implementation of actions aimed at enhancing effectiveness and efficiency of industrial emission reduction in terms of health promotion of the local population. Conclusions: We substantiate proposals for the necessity and sufficiency of taking remedial actions ensuring achievement of acceptable health risk levels as targets of the Comprehensive Emission Reduction Action Plan in Nizhny Tagil until 2024 and beyond.

scholarly journals Association between Intraoperative Blood Transfusion and Mortality and Morbidity in Patients Undergoing Noncardiac Surgery

2011 ◽  
Vol 114 (2) ◽  
pp. 283-292 ◽  
Author(s):  
Laurent G. Glance ◽  
Andrew W. Dick ◽  
Dana B. Mukamel ◽  
Fergal J. Fleming ◽  
Raymond A. Zollo ◽  
...  
Keyword(s):  
Blood Transfusion ◽  
Noncardiac Surgery ◽  
Pulmonary Complications ◽  
Wound Complications ◽  
Severe Anemia ◽  
Thromboembolic Complications ◽  
Mortality And Morbidity ◽  
Risk Of Death ◽  
Increased Risk ◽  
The Impact

Background The impact of intraoperative erythrocyte transfusion on outcomes of anemic patients undergoing noncardiac surgery has not been well characterized. The objective of this study was to examine the association between blood transfusion and mortality and morbidity in patients with severe anemia (hematocrit less than 30%) who are exposed to one or two units of erythrocytes intraoperatively. Methods This was a retrospective analysis of the association of blood transfusion and 30-day mortality and 30-day morbidity in 10,100 patients undergoing general, vascular, or orthopedic surgery. We estimated separate multivariate logistic regression models for 30-day mortality and for 30-day complications. Results Intraoperative blood transfusion was associated with an increased risk of death (odds ratio [OR], 1.29; 95% CI, 1.03-1.62). Patients receiving an intraoperative transfusion were more likely to have pulmonary, septic, wound, or thromboembolic complications, compared with patients not receiving an intraoperative transfusion. Compared with patients who were not transfused, patients receiving one or two units of erythrocytes were more likely to have pulmonary complications (OR, 1.76; 95% CI, 1.48-2.09), sepsis (OR, 1.43; 95% CI, 1.21-1.68), thromboembolic complications (OR, 1.77; 95% CI, 1.32-2.38), and wound complications (OR, 1.87; 95% CI, 1.47-2.37). Conclusions Intraoperative blood transfusion is associated with a higher risk of mortality and morbidity in surgical patients with severe anemia. It is unknown whether this association is due to the adverse effects of blood transfusion or is, instead, the result of increased blood loss in the patients receiving blood.

scholarly journals The role of heterocyclic aromatic amines in colorectal cancer: the evidence from epidemiologic studies

2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Loïc Le Marchand
Keyword(s):  
Colorectal Cancer ◽  
Aromatic Amines ◽  
Quantitative Methods ◽  
Biological Effects ◽  
Epidemiological Studies ◽  
Epidemiologic Studies ◽  
Red Meat ◽  
Heterocyclic Aromatic Amines ◽  
Intermediate Phenotype ◽  
Cancer Multiple

AbstractSince Dr. Sugimura’s discovery of heterocyclic aromatic amines (HAA) in broiled fish, many epidemiological studies have been conducted to investigate their role in human cancers, often focusing on colorectal cancer. The difficulty in measuring HAA exposure from meat and fish intake in these studies has resulted in inconsistent findings. Because studying individuals who may be particularly susceptible to the carcinogenic effects of HAA might facilitate the demonstration of a link with cancer, multiple studies have focused on individuals with the high activity phenotype for CYP1A2 and/or NAT2, the two main metabolic enzymes involved in the bioactivation of HAA. These investigations have also yielded inconsistent results. Two recent large pooled analyses of colorectal cancer studies have helped clarify the overall evidence. One was conducted in whites and reported no interaction of red meat intake and NAT2 genotype on risk in Whites. The other was conducted in Japanese and African Americans, two populations with high rates of the disease and a prevalence of the at-risk rapid NAT2 phenotype 10- and 2-fold greater than in whites, respectively. In those groups, a significant interaction was found, with the association of red meat with colorectal cancer being strongest among individuals with the rapid NAT2 phenotype, intermediate among those with the intermediate phenotype and not significant among those with the slow NAT2 phenotype. Recent research on biomarkers has focused on PhIP hair content, as a marker of exposure to HAA, and on DNA adducts using new sensitive quantitative methods, as markers of early biological effects. These advances, when brought to bear, may contribute greatly to the further elucidation of the carcinogenicity of HAA in humans.

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