18th Annual EBOSS Research Day | March 18th, 2022
Epidemiology, Biostatistics, and Occupational Health Student Society (EBOSS)
Published online: March 18, 2022Impact of intimate partner violence on women’s risk of HIV acquisition and engagement in HIV care cascade in sub-Saharan Africa: a meta-analysis of population-based surveys
2Medical Research Council (MRC) Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, United Kingdom
3Département de médecine sociale et préventive, Université Laval, Quebec City, QC, Canada
4Centre de recherche du CHU de Québec, Université Laval, Quebec City, QC, Canada
5Université Alassane Ouattara, Bouaké, Côte d’Ivoire
6Conselho Nacional de Combate ao HIV/Sida, Maputo, Mozambique
7Bristol Poverty Institute, School for Policy Studies, University of Bristol, Bristol, United Kingdom
8Department of Population Health, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
9Institute for Medical Information Processing, Biometry, and Epidemiology, Ludwig Maximilian University of Munich, Munich, Germany
10Department of Disease Control and Environmental Health, School of Public Health, College of Health Sciences, Makerere University, Kampala, Uganda
Corresponding Author: Salome Kuchukhidze , email salome.kuchukhize@mail.mcgill.ca
Abstract
Background: Achieving the 95-95-95 targets for HIV diagnosis, treatment, and viral load suppression (VLS) to end the AIDS epidemic hinges on eliminating manifestations of structural inequalities, including intimate partner violence (IPV). Sub-Saharan Africa (SSA) has among the world’s highest prevalence of IPV and HIV but an examination of the impact of IPV on HIV incidence, and women’s engagement in HIV care cascade is yet to be conducted. Methods: We pooled individual-level data from all available nationally representative surveys with information on physical and/or sexual IPV in SSA (2000-2020). We used generalized estimating equations with robust standard errors to estimate adjusted prevalence ratios (aPR) of lifetime and past year experience of IPV on HIV incidence (measured cross-sectionally by recent infection testing algorithm), past-year HIV testing (self-reported), antiretroviral therapy (ART) uptake, and VLS among ever-partnered women. Models were adjusted for age, age at first sex, residence type, women’s marital status, women’s education, and survey as a proxy of time and country. Results: Fifty-nine surveys were available from 30 countries, encompassing over 273,000 (Ni) respondents. Most surveys were from East Africa (48%); median survey year was 2013. Overall, 29% of women reported lifetime physical and/or sexual IPV (Ni= 81,399) and 21% experienced IPV in the past year (Ni= 59,560). Women exposed to past year IPV were 2.75 times (95%CI:1.26-6.00;Ni=19,852) more likely to have a recent HIV infection, adjusting for potential confounders. Past year IPV was not associated with HIV testing (aPR=1.00, 95%CI:0.98-1.01;Ni=273,603), but women living with HIV experiencing IPV in the last year were 10% less likely to be on ART (aPR=0.90; 95%CI:0.82-0.99;Ni=5,205) and to achieve viral suppression (aPR=0.90; 95%CI:0.81-0.99;Ni=5,205). Conclusion: IPV was associated with increased HIV incidence and, among women living with HIV, lower ART uptake and VLS. Preventing IPV is inherently imperative, and a crucial milestone in reducing population-level HIV incidence and burden.
Assessing the importance of past physical activity in predicting current injury risk using weighted cumulative exposure methods
2Centre for Clinical Epidemiology, Lady Davis Institute for Medical Research, Montreal, QC, Canada
3Centre for Outcomes Research and Evaluation, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
4Department of Mathematics and Statistics, McGill University, Montreal, QC, Canada
Corresponding Author: Chinchin Wang, email chinchin.wang@mail.mcgill.ca
Abstract
Background: While physical activity is important for health, it can also lead to injury. Injury risk is affected by current and past activity. Past activity may predispose to injury through tissue damage and insufficient recovery or protect against injury by strengthening tissue with sufficient recovery. It is unclear what the relevant time window and relative importance of past activity are in predicting time to injury. Flexible weighted cumulative exposure (WCE) methods may be applicable to this problem. Objective: Determine the relative importance of activity done in past weeks in predicting current injury risk conditional on activity in the current week. Methods: We applied WCE methods to weekly data from 1670 schoolchildren collected over 5.5 years. We estimated weight functions for the association between the number of activity sessions in past weeks and time to first injury, conditioning on the number of activity sessions in the current week. We estimated functions using different time windows and used the Akaike Information Criterion to determine the best fitting function. We generated 95% confidence bands by bootstrap resampling. Results: Higher levels of activity recorded in the previous 2 to 9 weeks were predictive of increased risk of injury, as reflected by positive weights (Figure 1). Given the same recent activity history, activity more than 9 weeks previous appeared protective. There was limited evidence of a protective association for activity recorded in the previous week, with great uncertainty. This may be expected even if previous week activity is not causally protective. Those with many activities in the previous week have smaller increases in activity in the current week relative to those with few activities in the previous week. This smaller proportional increase in activity is expected to lead to fewer injuries. Conclusion: WCE methods provide insight into the time-specific associations between past physical activity history and injury.
The association between the incidence of Lyme disease in the United States and indicators of greenness and land cover
2Department of Medicine, McGill University, Montreal, QC, Canada
3Centre for Outcomes Research and Evaluation, Research Institute of the McGill University Hospital Centre, Montreal, QC, Canada
4Department of Biosystems Engineering, and Remote Sensing / Spatial Analysis – GIDP program, University of Arizona, Tucson, AZ, United States
Corresponding Author: Sydney Westra, email sydney.westra@mail.mcgill.ca
Abstract
Background: Lyme disease is the most common vector-borne illness in the United States. Incidence is related to specific environmental conditions such as temperature, metrics of land cover, and species diversity. Objective: To determine whether greenness, as measured by the Normalized Difference Vegetation Index (NDVI), and other selected indices of land cover were associated with the incidence of Lyme disease in the northeastern USA, 2000-2018. Materials and Methods: We conducted an ecological analysis of incidence rates in counties of 15 “high” incidence states and the District of Columbia for 2000-2018. Annual counts of Lyme disease by county were obtained from the US Centers for Disease Control and values of NDVI were acquired from the Moderate Resolution Imaging Spectroradiometer instrument aboard Terra and Aqua Satellites. County-specific values of population density, area of land and water were obtained from the US Census. Using quasi-Poisson regression, multivariable associations were estimated between the incidence of Lyme disease NDVI, land cover variables, human population density, and calendar year. Results: We found that incidence increased by 7.1% per year (95% confidence interval: 6.8-8.2%). Land cover variables showed complex non-linear associations with incidence: average county-specific NDVI showed a ‘u-shaped” association, the standard deviation of NDVI showed a monotonic upward relationship, population density showed a decreasing trend, areas of land and water showed “n”-shaped relationships. We found an interaction between average and standard deviation of NDVI, with the highest average NDVI category, increased standard deviation of NDVI showed the greatest increase in rates. Discussion: These associations cannot be interpreted as causal but indicate that certain patterns of land cover may have the potential to increase exposure to infected ticks and thereby may contribute indirectly to increased rates. Public health interventions could make use of these results in informing people where risks may be high.
Incidence and outcomes of pediatric cancers during the COVID-19 pandemic in Canada: an interrupted time series analysis
2Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
3Centre Hospitalier Universitaire Sainte-Justine, Department of Pediatric Emergency Medicine, Montreal, QC, Canada
4Montreal Children’s Hospital, Division of Pediatric Emergency Medicine, Montreal, QC, Canada
5Division of General Pediatrics, Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, Montreal, QC, Canada
6Department of Social and Preventive Medicine, School of Public Health, Université de Montréal, Montreal, QC, Canada
Corresponding Author: Francesca del Giorgio, email francesca.delgiorgio@mail.mcgill.ca
Abstract
The worldwide reduction in pediatric emergency department (ED) visits during the COVID-19 pandemic led to concerns of worse prognosis for pediatric cancer patients resulting from delayed diagnosis and treatment. This study aimed to quantify whether there was a change in incidence of pediatric emergency department (ED) visits, oncology ward admissions, and new diagnoses for children with cancer during the first year of the COVID-19 pandemic relative to the pre-pandemic incidence in Montreal, Quebec. This study made use of the electronic medical records of two pediatric hospitals in Montreal to identify children diagnosed with suspected or confirmed oncological conditions between January 2016 and May 2021 (N=164 000 ED visits/year). An interrupted timeseries design was used to quantify the change in bi-monthly incidence at the onset and throughout the first 14 months of the pandemic of ED visits, oncology ward admissions, and new cancer diagnoses via Poisson or negative binomial regression adjusted for baseline trend, seasonality, and site. A 39% reduction in overall ED visits for children with suspected and confirmed cancers was observed at the onset of the pandemic (Incidence Rate Ratio (IRR)=0.61, 95% CI=0.48 ; 0.78), followed by a gradual increase in cases to baseline throughout the pandemic (IRR=1.11, 95% CI=1.04 ; 1.19). There was no change in incidence of admissions to the oncology ward or in incidence of new cancer diagnoses either at the onset or throughout the pandemic. Although there was a reduction in ED visits for suspected and confirmed cancer patients, there was no change in pediatric oncology admissions or new cancer diagnoses signifying no major delays in treatment of pediatric cancer patients during the COVID-19 pandemic.
Flexible modeling of the association between cumulative exposure to low-dose ionizing radiation from cardiac procedures and risk of hematopoietic cancer in children with congenital heart disease
2McGill Adult Unit for Congenital Heart Disease, McGill University Health Center, Montreal, QC, Canada
Corresponding Author: Ariane J. Marelli, email ariane.marelli@mcgill.ca
Abstract
Background: High-dose ionizing radiation is a well-established risk factor for childhood malignancies, including hematopoietic cancers (HC). However, data on the effect of low-dose ionizing radiation (LDIR) from medical imaging is conflicting and scant, especially in the pediatric population with congenital heart diseases (CHD). This study evaluated the association between cardiac LDIR exposure and hematopoietic cancers among children with CHD. Methods: A nationwide population-based cohort study was conducted using the Canadian Congenital Heart Disease (CanCHD) database. The study population included children born between 1999 and 2017 with at least one CHD diagnosis in their medical records. The cumulative dose of ionizing radiation corresponding to cardiac diagnostic and therapeutic procedures was quantified considering a 6-month exposure lag. The recency-weighted cumulative exposure (WCE) model, a flexible extension of Cox’s proportional hazards model, was used to assess the association. Results: We identified 139,975 children with CHD born between 1999 and 2017 and followed them for 1,388,681 person-years since birth. In this population, 718 hematopoietic cancer cases were observed. Children with HC were exposed to low-dose ionizing radiation earlier in life (median age at first exposure: 6 vs. 10 months; p=0.03) and had more procedures than those without cancer (mean number of procedures: 0.4 vs. 0.2; p<0.001). The cases received higher cumulative LDIR doses than their counterparts (mean dose: 2.3 vs. 1.1 mSv; p<0.001). We observed that cumulative LDIR doses within five years were associated with increased risk of hematopoietic cancer with the maximum association magnitude around 2 years. Conclusion: This is the first large population-based study documenting increased risk of HC associated with increased dose and recency of the LDIR exposure among children with CHD. Along with these findings, future studies focusing on detecting a threshold effect will help physicians decide the exposure point at which increased surveillance on LDIR exposure should be initiated.
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.