Population-based Sampling Research Articles

Prevalence of allergic diseases and their symptoms in schoolchildren according to the birth mode.

The relationship between birth by cesarean section (CS) and allergic diseases' prevalence continues to be controversial. We aimed to investigate if being born by CS is associated with the prevalence of allergic diseases and their symptoms in schoolchildren. This study included children between 6 and 7 years of age, selected by population-based sampling. We investigated the presence of allergic diseases and their symptoms, family history of asthma, smoking in parents, breastfeeding, exposure to pets, the season of birth, number of siblings, consumption of unpasteurized cow's milk, and mode of birth. We included 1003 subjects (526 girls), of which 44.2% were born through CS. The prevalence of allergic diseases did not differ according to birth mode. Asthma in either parent, current smoking by the mother, breastfeeding, and unpasteurized cow's milk consumption were associated with wheezing at some time in life. No association between CS birth mode and allergic diseases and their symptoms was found.

Seroprevalence of SARS-CoV-2 Antibodies in Rhode Island From a Statewide Random Sample.

Objectives. To characterize statewide seroprevalence and point prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Rhode Island.Methods. We conducted a cross-sectional survey of randomly selected households across Rhode Island in May 2020. Antibody-based and polymerase chain reaction (PCR)-based tests for SARS-CoV-2 were offered. Hispanics/Latinos and African Americans/Blacks were oversampled to ensure adequate representation. Seroprevalence estimations accounted for test sensitivity and specificity and were compared according to age, race/ethnicity, gender, housing environment, and transportation mode.Results. Overall, 1043 individuals from 554 households were tested (1032 antibody tests, 988 PCR tests). The estimated seroprevalence of SARS-CoV-2 antibodies was 2.1% (95% credible interval [CI] = 0.6, 4.1). Seroprevalence was 7.5% (95% CI = 1.3, 17.5) among Hispanics/Latinos, 3.8% (95% CI = 0.0, 15.0) among African Americans/Blacks, and 0.8% (95% CI = 0.0, 2.4) among non-Hispanic Whites. Overall PCR-based prevalence was 1.5% (95% CI = 0.5, 3.1).Conclusions. Rhode Island had low seroprevalence relative to other settings, but seroprevalence was substantially higher among African Americans/Blacks and Hispanics/Latinos. Rhode Island sits along the highly populated northeast corridor, making our findings broadly relevant to this region of the country. Continued monitoring via population-based sampling is needed to quantify these impacts going forward.

Global Distribution of Sex Differences in the Incidence and Prevalence of Any Dementia, Alzheimer's Disease, and Vascular Dementia: A Systematic Review and Meta-Analysis

Background: We estimated global incidence of Alzheimer’s disease (AD), Vascular dementia (VaD), and Any dementia reported evaluated whether country level socio-demographic factors could explain variation in gender differences in dementia prevalence and incidence. Methods: We conducted a systematic review with meta-analysis to obtain estimates of incidence and prevalence of AD, VaD and Any dementia using random effects meta-analysis. We included population-based studies with clinical diagnoses or validated dementia screening instruments. We excluded studies lacking a valid clinical diagnoses, population-based sampling, or gender stratified estimates. We used meta-regression to evaluate how country specific factors of life-expectancy, education, and gender differences in development, unemployment and inequality indices influenced estimates. Findings: Our searches identified 205 eligible studies from 8731 articles, representing 998 187 participants across 43 countries. Global incidence (95% CI) of Any dementia/1000 person-years for men at age 60-64, 66-69, 70-74, 75-79, 80-84, 85-89 and 90+ was 2·5 (1·9-3·2), 5·1 (4·0-6·5). 10·1 (7·9-12·8), 19·7 (15·5-24·9), 34·0 (26·9, 43·0), 59·6 (47·3, 74·8), and 84·5 (67·5, 105·4) respectively. For women the corresponding figures were 1·8 (1·3-2·5), 3·4 (2·5-4·7), 9·1 (6·6-12·4), 23·7 (17·3-32·4), 46·44 (34·1, 62·9), 84·54 (62·8, 112·9), and 142·2 (107·4, 185·9). There was no difference in incident Any dementia, or for AD or VaD, or prevalence of Any dementia, in any age group except for the 90+, where it was higher in women. AD was more prevalent in women at most ages, and VaD was only more prevalent in men aged 65-69. Meta-regression revealed that gender differences in Any dementia prevalence, may be explained by the gender differences in life expectancy and education. Interpretation: Globally, there are no gender differences in dementia incidence except in the 90+ age-group. Greater focus on the role gender inequality and life expectancy play as a potential explanations of gender differences in dementia and AD prevalence is needed. Registration Details: The review was registered with the International Prospective Register of Systematic Reviews (PROSPERO, CRD42017053915) and reported in accordance with the PRISMA Statement (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). Funding Information: ARC Laureate Fellowship FL190100011, National Health and Medical Research Council (NHMRC) Grants 1100579, 1102694. NHMRC Dementia Centre for Research Collaboration Declaration of Interests: The authors have no conflicts of interest.

Post-intervention epidemiology of STH in Bangladesh: Data to sustain the gains.

In 2008, Bangladesh initiated Preventive Chemotherapy (PCT) for school-age children (SAC) through bi-annual school-based mass drug administration (MDA) to control Soil-Transmitted Helminth (STH) infections. In 2016, the Ministry of Health and Family Welfare's Program on Lymphatic Filariasis Elimination and STH (ELFSTH) initiated district-level community impact assessments with Children Without Worms (CWW) using standardized, population-based sampling to measure the post-intervention STH burden across all ages (≥ 1 yr) for the three STH species. The Integrated Community-based Survey for Program Monitoring (ICSPM) was developed by CWW and was used to survey 12 districts in Bangladesh from 2017-2020. We excluded the first two district data as piloting caused some sampling errors and combined the individual demographic and parasite-specific characteristics from the subsequent 10 districts, linking them with the laboratory data for collective analysis. Our analysis identified district-specific epidemiologic findings, important for program decisions. Of the 17,874 enrolled individuals, our results are based on 10,824 (61.0%) stool samples. Overall, the prevalence of any STH species was substantially reduced to 14% from 79.8% in 2005. The impact was similar across all ages. STH prevalence was 14% in 10 districts collectively, but remained high in four districts, despite their high reported PCT coverage in previous years. Among all, Bhola district was unique because it was the only district with high T.trichuris prevalence. Bangladesh successfully lowered STH prevalence across all ages despite targeting SAC only. Data from the survey indicate a significant number of adults and pre-school age children (PSAC) were self-deworming with purchased pills. This may account for the flat impact curve across all ages. Overall prevalence varied across surveyed districts, with persistent high transmission in the northeastern districts and a district in the central flood zone, indicating possible service and ecological factors. Discrepancies in the impact between districts highlight the need for district-level data to evaluate program implementation after consistent high PCT coverage.

Population Based Birth Prevalence of Disease-Specific Perinatal Stroke.

Perinatal stroke encompasses multiple disease-specific cerebrovascular syndromes that cause lifelong neurodevelopmental morbidity for millions worldwide. Acute presentations include neonatal arterial ischemic stroke (NAIS), neonatal cerebral sinovenous thrombosis, and neonatal hemorrhagic stroke (NHS). Delayed presentations include arterial presumed perinatal ischemic stroke, periventricular venous infarction, and presumed perinatal hemorrhagic stroke. Our objective was to define the birth prevalence of all subtypes of perinatal stroke by using a population-based cohort. The Alberta Perinatal Stroke Project is a research cohort established in 2008 in southern Alberta, Canada, with prospective (2008-2017) and retrospective (1990-2008) enrollment leveraging universal health care at a single tertiary care pediatric center. The primary outcome was the estimated birth prevalence of each perinatal stroke syndrome, secondary outcomes were birth prevalence over time, sex ratios, and change in age at diagnosis. Analysis included Poisson regression, Wilcoxon rank test, and Fisher exact test. The overall estimated birth prevalence of term-born perinatal stroke was 1:1100. The estimated birth prevalence was 1:3000 for NAIS, 1:7900 for arterial presumed perinatal ischemic stroke, 1:6000 for periventricular venous infarction, 1:9100 for cerebral sinovenous thrombosis, 1:6800 for NHS, and 1:65000 for presumed perinatal hemorrhagic stroke. The apparent birth prevalence of NAIS and NHS increased over time. There were more males affected than females. The age at diagnosis decreased for late-presenting stroke types. The estimated birth prevalence of term perinatal stroke is higher than previous estimates, which may be explained by population-based sampling of disease-specific states. This emphasizes the need for further studies to better understand the disease-specific pathophysiology to improve treatment and prevention strategies.

Blood Lead Level Estimates for Low- and Middle-Income Countries

Background Since the global phase-out of leaded petrol, reports have suggested that lead exposure remains substantial or is increasing in some low- and middle-income countries (LMICs). However, few studies have recently attempted to systematically assess blood lead levels (BLLs) over the full range of LMICs. Methods We searched the PubMed database with the keywords ‘blood,’ ‘lead,’ and ‘[country name]’ for the 137 countries in World Bank LMIC country groupings, yielding 12,695 articles published between 1 January 2010 and 31 October 2019. They were then screened using pre-defined criteria. Data on BLLs were extracted and pooled, as appropriate, to make country-specific estimates of the distribution of background BLL levels among children and adults, along with information on specific sources of exposure where available. Findings The review returned 538 papers containing 1,126 sampled populations from 48 countries comprising 1,012,456 individuals. Background BLLs could be pooled and were used to estimate background BLL distributions for 1·28 billion children in 34 countries. Of these, 631 (95%CI: 395–778) million (49%) were estimated to have BLLs exceeding the U.S. Centers for Disease Control’s reference value of 5 µg/dL. The primary reported sources of exposure were occupations (for adults), emissions from battery manufacturing/recycling, electronic waste, mining, and other industries, and consumer products. Interpretation Many children have BLLs exceeding 5 µg/dL in LMICs despite leaded petrol phase-outs. Given the toxicity of lead, even at low levels of exposure, urgent attention is required to control exposures and expand population-based sampling in countries with no or scant data.

Environmental risk factors for endometriosis: A critical evaluation of studies and recommendations from the epidemiologic perspective.

Recent studies of environmental chemicals and endometriosis were critically evaluated from the epidemiologic perspective to identify aspects of study design and analyses that may contribute to discrepant results across studies. Of the 29 studies reviewed, 12 studies used new approaches to population-based sampling. The remaining studies were conducted primarily among patients undergoing pelvic surgery; controls may not represent the exposure experience of the underlying study base, resulting in biased estimates of associations. Most studies used biologic specimens collected near diagnosis and varied in analytic approaches to minimize bias. Few studies investigated ovarian, deep-infiltrating, and peritoneal endometriosis presentations separately. Recommendations to move the field forward include: (1) control selection from a defined study base, (2) exposure characterization during the etiologically-relevant window, (3) employment of best practices to minimize bias in analyses, and (4) separate consideration of endometriosis presentations that may be etiologically-distinct entities.

'Too many BeEPs in our teens!' Behavioral and emotional problems in a large group of Italian adolescents.

One in six adolescents suffers from mental health problems. Despite the presence of general information on Italian adolescents' mental health, researches conducted with standardized assessment tools are scarce in the literature. We evaluated the prevalence of self-reported behavioral and emotional problems in a group of Italian adolescents and examined their relation to socio-demographical variables. This population-based sampling survey was conducted on high school students aged 14-18 from urban areas of Rome and Latina. Participants completed Youth Self-Report (YSR) and a socio-demographic schedule to collect information on age, gender, type of school attended, socio-economic status, urbanicity. Final sample consisted of 1400 adolescents (38.61% male, mean age 16 years, s.d. 1.42). Prevalence of Internalizing Problems, Externalizing Problems and Total Problems was 29.55%, 18.34% and 24.13%. In our multivariable model, Internalizing Symptoms were not explained by sociodemographic variables while Externalizing Symptoms were explained by Male Gender [OR = 1.53 (1.14-2.06)], older age [OR = 2.06 (1.52-2.79)] and attending a Technical and Professional Institute [OR = 2.15 (1.53-3.02)], with an adjusted R2 = 4.32%. Total Problems were explained by School Type [Technical and Professional Institutes and Art and Humanities v. Grammar and Science School; OR respectively 1.93 (1.40-2.67) and 1.64 (1.08-2.47)], adjusted R2 = 1.94. The study provides, for the first time, evidence of a great prevalence of self-reported behavioral and emotional problems in a large sample of Italian adolescents, highlighting the role of different socio-demographic variables as risk factors for externalizing behaviors. Our results emphasize the urgent need for implementing prevention programs on mental health in adolescence.

Effect of Statins on the Risk of Poststroke Pneumonia: National Population-Based Cohort Study.

PurposeStatins are widely prescribed medications for treatment of dyslipidemia and prevention of cardiovascular disease. Beyond their lipid-lowering property, statins exhibit multiple pleiotropic and antimicrobial effects. We aimed to investigate the effect of statins on the long-term risk of pneumonia after acute ischemic stroke.MethodsThis retrospective observational research was performed using South Korean National Health Insurance Service claim data, which consist of population-based random sampling. We included patients discharged with acute ischemic stroke (I63 in the ICD10) and no prior history of pneumonia. The primary outcome measure was the occurrence of pneumonia determined based on ICD10 code J09–J18. Treatment with statins during follow-up was collected as a time-dependent variable based on prescription records.ResultsA total of 7,001 subjects with acute ischemic stroke and no prior history of pneumonia were included. During the mean 3.96-year follow-up, pneumonia occurred in 1,715 subjects (24.5%). On multivariate time-dependent Cox proportional hazard–regression analyses, significant preventive benefit of treatment with statins against pneumonia was noted (adjusted HR 0.86, 95% CI 0.77–0.97). Compared to no use of statin, adjusted HRs (95% CIs) for current use of low–intermediate high-intensity statins were 0.88 (0.78–0.99) and 0.49 (0.27–0.87), respectively.ConclusionOur retrospective national cohort study found reduced risk of poststroke pneumonia with statin therapy after acute ischemic stroke. Our study suggests that treatment with statins may have a preventive effect against the common complication of poststroke pneumonia.

Normative Peak Cardiopulmonary Exercise Test Responses in Canadian Adults Aged ≥40 Years

Up-to-date normative reference sets for cardiopulmonary exercise testing (CPET) are important to aid in the accurate interpretation of CPET in clinical or research settings. This study aimed to (1) develop and externally validate a contemporary reference set for peak CPET responses in Canadian adults identified with population-based sampling; and (2) evaluate previously recommended reference equations for predicting peak CPET responses. Participants were healthy adults who were≥40 years old from the Canadian Cohort Obstructive Lung Disease who completed an incremental cycle CPET. Prediction models for peak CPET responses were estimated from readily available participant characteristics (age, sex, height, body mass) with the use of quantile regression. External validation was performed with a second convenience sample of healthy adults. Peak CPET parameters that were measured and predicted in the validation cohort were assessed for equivalence (two one-sided tests of equivalence for paired-samples and level of agreement (Bland-Altman analyses). Two one-sided tests of equivalence for paired samples assessed differences between responses in the derivation cohort using previously recommended reference equations. Normative reference ranges (5th-95th percentiles) for 28 peak CPET parameters and prediction models for 8 peak CPET parameters were based on 173 participants (47%male) who were 64 ± 10 years old. In the validation cohort (n= 84), peak CPET responses that were predicted with the newly generated models were equivalent to the measured values. Peak cardiac parameters predicted by the previously recommended reference equations by Jones and colleagues and Hansen and colleagues were significantly higher. This study provides reference ranges and prediction models for peak cardiac, ventilatory, operating lung volume, gas exchange, and symptom responses to incremental CPET and presents the most comprehensive reference set to date in Canadian adults who were≥40 years old to be identified with population-based sampling.

Preferences for long-acting Pre-Exposure Prophylaxis (PrEP) for HIV prevention among South African youth: results of a discrete choice experiment.

IntroductionExisting biomedical HIV prevention options, though highly effective, present substantial adherence challenges. End‐user input on early‐stage design of new HIV prevention approaches is critical to yielding products that achieve high uptake and adherence. The iPrevent Study examined youths’ preferences for key attributes of long‐acting Pre‐Exposure Prophylaxis (PrEP), with a focus on characteristics pertinent to product delivery alongside key modifiable product attributes.MethodsA discrete choice experiment was conducted with female and male youth aged 18 to 24 in two high‐density communities in Cape Town, South Africa during the period July 2017 to January 2019. Sexually active, PrEP‐naïve youth were recruited using population‐based sampling; targeted sampling was used to enrol men who have sex with men (MSM). In a series of nine questions, participants were asked to choose between two hypothetical products composed of five attributes (form, dosing frequency, access, pain, insertion site). We used a random‐parameters logit model to estimate preference weights and trade‐offs among product alternatives. We examined differences across three subgroups: females, men who have sex with only women (MSW) and MSM.ResultsA total of 807 participants (401 female) were enrolled with a median age of 21 years. Males included 190 MSM. Most youth had tested for HIV (95%) and reported being HIV‐negative (91%). Across all groups, duration of effectiveness was the most important attribute, with strong preference for less frequent dosing. Injections were favoured over implants, though these preferences were strongest for females and MSM. Females preferred a product offered at a health clinic and disliked pharmacy access; all groups preferred the arm as the insertion site. Youth were willing to trade their preferred product form for longer duration.ConclusionsYouth indicated strong preferences for longer duration products. Each attribute nonetheless influenced preferences, offering insight into trade‐offs that inform long‐acting PrEP development.

The global burden of musculoskeletal injury in low and lower-middle income countries: A systematic literature review.

Background:While the global burden of musculoskeletal injury is increasingly recognized, few epidemiologic studies have specifically recorded its incidence or prevalence, particularly in low- and middle-income countries. Understanding the burden of musculoskeletal injury relative to other health conditions is critical to effective allocation of resources to mitigate the disability that results from trauma. The current study aims to systematically review the existing primary literature on the incidence and prevalence of pelvic and appendicular fractures, a major component of musculoskeletal injury, in low- and lower-middle income countries (LMICs).Methods:This study conforms to the systematic review and traditional meta-analysis guidelines outlined in the PRISMA-P statement. Incidence rates were calculated as the occurrence of new fracture cases per 100,000 person-years, and prevalence as total fracture cases per population sample, reported as percentages.Results:The literature search yielded 3497 total citations. There were 21 full-text articles, representing 14 different countries, selected for data extraction. Included studies reported a wide range of incidence and prevalence rates, with an overall mean fracture incidence ranging from 779 (95% CI: 483.0–1188.7) to 1574 (95% CI: 1285.1–1915.1) per 100,000 person-years.Conclusion:Better understanding the unmet burden of musculoskeletal injury in LMICs is critical to effectively allocating resources and advocating for underserved populations. To address existing gaps and heterogeneity within the literature, future research should incorporate population-based sampling with broader geographic representation in LMICs to more accurately capture the burden of disease.

Evaluation of a health promotion intervention associated with birthing centres in rural Nepal.

Birthing centres (BC) in Nepal are mostly situated in rural areas and provide care for women without complications. However, they are often bypassed by women and their role in providing good quality maternity services is overlooked. This study evaluated an intervention to increase access and utilisation of perinatal care facilities in community settings. This longitudinal cross-sectional study was conducted over five years in four villages in Nepal and included two BCs. An intervention was conducted in 2014-2016 that involved supporting the BCs and conducting a health promotion programme with local women. Population-based multi-stage sampling of women of reproductive age with a child below 24 months of age was undertaken. Household surveys were conducted (2012 and 2017) employing trained enumerators and using a structured validated questionnaire. The collected data were entered into SPSS and analysed comparing pre- and post-intervention surveys. The intervention was associated with an increase in uptake in facility birth, with an increase in utilisation of perinatal services available from BCs. The post-intervention survey provided evidence that women were more likely to give birth at primary care facilities (OR 5.60, p-value <0.001) than prior to the intervention. Similarly, the likelihood of giving birth at a health facility increased if decision for birthplace was made jointly by women and family members for primary care facilities (OR 1.76, p-value 0.023) and hospitals/tertiary care facilities (OR 1.78, p-value 0.020. If women had less than four ANC visits, then they were less likely to give birth at primary care facilities (OR 0.39, p-value <0.001) or hospitals/tertiary care facilities (OR 0.63, p-value 0.014). Finally, women were less likely to give birth at primary care facilities if they had only primary level of education (OR 0.49, p-value 0.014). BCs have the potential to increase the births at health facilities and decrease home births if their services are promoted by the local health promoters. In addition, socio-economic factors including women's education, the level of women's autonomy and having four or more ANC visits affect the utilisation of perinatal services at the health facility.

Evidence accumulation models with R: A practical guide to hierarchical Bayesian methods

Evidence accumulation models are a useful tool to allow researchers to investigate the latent cognitive variables that underlie response time and response accuracy. However, applying evidence accumulation models can be difficult because they lack easily computable forms. Numerical methods are required to determine the parameters of evidence accumulation that best correspond to the fitted data. When applied to complex cognitive models, such numerical methods can require substantial computational power which can lead to infeasibly long compute times. In this paper, we provide efficient, practical software and a step-by-step guide to fit evidence accumulation models with Bayesian methods. The software, written in C++, is provided in an R package: 'ggdmc'. The software incorporates three important ingredients of Bayesian computation, (1) the likelihood functions of two common response time models, (2) the Markov chain Monte Carlo (MCMC) algorithm (3) a population-based MCMC sampling method. The software has gone through stringent checks to be hosted on the Comprehensive R Archive Network (CRAN) and is free to download. We illustrate its basic use and an example of fitting complex hierarchical Wiener diffusion models to four shooting-decision data sets.

National Cross-Sectional Study of Community-Based Adverse Drug Reactions in Saudi Arabia

BackgroundAn adverse drug reaction (ADR) is a response to a medicine that is not intended and is harmful, and which occurs at normal dose levels for humans. Currently, there are no estimates of the population-based prevalence of ADRs in the Kingdom of Saudi Arabia (KSA).ObjectiveThe aims of this study were to (1) estimate the population-based prevalence of ADRs in KSA, (2) describe the ADRs experienced by survey respondents, and (3) investigate the level of awareness of the ADR reporting system.Patients and MethodsThis was a cross-sectional survey using stratified, population-based sampling conducted at a chain of community pharmacies.ResultsAnalysis was conducted on 5228 surveys; 50.17% of respondents were males, and the mean age was 39 ± 15 years (min = 18, max = 98). The sample prevalence of ADRs was 23.45% (95% CI 22.30–24.60%, P < 0.001). The estimated population prevalence (after weighting) was 28.00% (26.10–30.00%). Gastrointestinal disorders were the most commonly reported ADRs (58.73%), followed by general disorders and administration site conditions (19.74%). The largest drug class that was reported to lead to ADRs was nonsteroidal anti-inflammatory drugs (NSAIDs) (11%). Over 19% of the respondents who experienced an ADR required medical intervention to control the suffering induced by the ADR. Of the respondents who experienced an ADR, 371 (30.26%) were aware of the ADR reporting system but only 53 (14.29%) said that they had filed a report in the system.ConclusionsOur study estimated that 28% of the population experienced an ADR over a 1-year period in KSA. Risk factors for ADR included certain chronic disease groups and the use of certain classes of medications. Regulatory authorities in KSA intend to conduct more research and deploy educational interventions to reduce ADR rates in KSA. This will hopefully occur in an international context that promotes the standardized measurement of ADRs in the community. A subset of findings from this report was presented in an oral presentation at the Saudi Food and Drug Authority (SFDA) Annual Conference, September 27, 2018. In addition, a subset of findings from this report were presented on a poster at the International Conference of Pharmacoepidemiology and Therapeutic Risk Management (ICPE), August 27, 2019.Electronic supplementary materialThe online version of this article (10.1007/s40801-020-00186-8) contains supplementary material, which is available to authorized users.

Abstract 51: The Incidence of Perinatal Stroke is 1:1200 Live Births: A Population-Based Study in Alberta Canada

Introduction: Perinatal stroke encompasses six cerebrovascular syndromes which occur between the 20 th week of gestation and the 28 th post-natal day. Morbidity is significant including motor, language, behavioral, and cognitive challenges, as well as epilepsy. Acute presentations include neonatal arterial ischemic stroke (NAIS), neonatal cerebral sinovenous thrombosis (CSVT), and neonatal hemorrhagic stroke (NHS). Delayed presentations include arterial presumed perinatal ischemic stroke (APPIS), periventricular venous infarction (PVI), and presumed perinatal hemorrhagic stroke (PPHS). Inconsistent terminology and lack of population-based cohorts has limited accurate measurement of disease-specific perinatal stroke incidence. Our objective was to define the incidence of the subtypes of perinatal stroke using a population-based cohort. Methods: The Alberta Perinatal Stroke Project is a research cohort established in 2008 in Southern Alberta, Canada (population ~2.1 million). Leveraging universal health care at a single tertiary care pediatric center facilitated true population-based epidemiology. Patients included had neuroimaging-confirmed perinatal stroke. Case acquisition included exhaustive retrospective hospital and ICD code searches (1990-2008) and prospective enrollment from all NICU and neurology/stroke clinics (2008-2018). Live birth rate denominators were determined from the provincial census. Results: The overall incidence of perinatal stroke in Southern Alberta from 2008-2018 was 81 cases per 100,000 live births, or 1 case per approximately 1200 live births. The incidence of NAIS was 31 per 100,000 (~1/3000), APPIS was 11 per 100,000 (~1/9000), PVI was 18 per 100,000 (~1/5500), and CSVT was 10 per 100,000 (~1/9800). The incidence of NAIS increased after implementing prospective case identification, from 8.5 (95% CI 5.3-11.6) per 100,000 to 31 per 100,000 (95% CI 24.4-38.2), p&lt;0.00001, the remainder of stroke subtypes were stable over time. Conclusions: The overall incidence of perinatal stroke in Southern Alberta is 1:1200 live births. Population-based sampling of disease-specific states may explain why this rate is much higher than previous estimates.

Risk Factors for Falls in Older Adults Experiencing Homelessness: Results from the HOPE HOME Cohort Study.

More than half of homeless adults are of age ≥ 50years. Falls are a common cause of morbidity in older adults in the general population. Risk factors for falls in the general population include poor health, alcohol use, and exposure to unsafe environments. Homeless adults aged ≥ 50 have a high prevalence of known risk factors and face additional potential risks. To examine the prevalence of and risk of falling in a cohort of older homeless adults. Longitudinal cohort study with participant interviews every 6months for 3years; data were analyzed using generalized estimating equations (GEEs). Three hundred fifty adults aged ≥ 50, homeless at study entry, recruited via population-based sampling. The dependent variable is any falls in prior 6months; independent variables include individual (i.e., illness, behaviors) and social/environmental (i.e., social support, experiencing violence, living unsheltered) factors. Over three quarters of participants were men (77.1%) and Black (79.7%). The median age was 58 (IQR 54, 61). At baseline, one third (33.7%) reported a fall in the prior 6months. At follow-up visits, 23.1% to 31.2% of participants reported having fallen. In GEE models, individual risk factors (non-Black race, being a women, older age, functional impairment, urinary incontinence, history of stroke, and use of assistive devices, opioid, and marijuana) were associated with increased odds of falls. Environmental and social factors (spending any nights unsheltered (adjusted odds ratio (AOR) = 1.42, CI=1.10-1.83) and experiencing physical assault (AOR = 1.67, CI=1.18-2.37) were also associated. Older homeless adults fall frequently. Likely contributors include having a high prevalence of conditions that increase the risk of falls, compounded by heightened exposure to unsafe environments. Fall prevention in this population should target those at highest risk and address modifiable environmental conditions. Providing shelter or housing and addressing substance use could reduce morbidity from falls in homeless older adults.

Implementation of a Community-Based Hybrid HIV Testing Services Program as a Strategy to Saturate Testing Coverage in Western Kenya.

Knowledge of HIV status is the entry point for linkage to prevention, care, and treatment, and the first step toward achieving the UNAIDS 90-90-90 targets. Most countries rely on proxies for estimating testing saturation, including periodic population-based sampling and yield (number positive among those tested). We conducted a community-based "Hybrid" HIV testing services (HTS) program to identify persons unaware of their HIV-positive status. Homa Bay County, Kenya; July-September, 2016. We conducted community mapping, household census, multi-disease community health campaigns (CHCs), and home-based tracking. HIV testing eligibility was based on 2015 national guidelines. The previously unidentified fraction (PUF) was defined as the proportion of newly identified persons living with HIV (PLWH) out of all previously identified and newly identified PLWH. The Hybrid HTS program reached 28,885 persons in total: 25,340 residents and 3545 nonresidents. There were 19,288 persons reached through CHCs and tracking. Of 11,316 individuals eligible for HIV testing, 9463 (83%) accepted testing, including 1230 (13%) first-time testers. There were 115 newly identified PLWH of 1589 total HIV-positive persons, representing a 7.2% PUF. Of 93 newly identified PLWH at the CHCs, 68% initiated same-day antiretroviral therapy. The Hybrid HTS program identified persons previously unaware of their HIV-positive status, thereby enabling linkage to care and same-day treatment and reducing onward transmission risk. An approach focused on identifying persons unaware of their HIV-positive status in combination with ascertaining the PUF has the potential to better target testing strategies to identify >90% of PLWH in a community.

The prevalence of scabies, pyoderma and other communicable dermatoses in the Bijagos Archipelago, Guinea-Bissau.

IntroductionSkin diseases represent a significant public health problem in most low and middle income settings. Nevertheless, there is a relative paucity of high-quality epidemiological data on the prevalence of these conditions.Materials/MethodsWe conducted two cross-sectional population-based skin-surveys of children (6 months to 9 years old) in the Bijagós Archipelago of Guinea-Bissau during the dry season (February-March 2018) and the wet season (June-July 2018). Following a period of training, a nurse performed a standardised examination for communicable dermatoses for each participant. We calculated the prevalence of each skin condition and investigated demographic associations.Results1062 children were enrolled in the dry season survey of whom 318 (29.9%) had at least one skin diseases. The most common diagnosis was tinea capitis (154/1062, 14.5% - 95% CI 12.5–16.8%) followed by tinea corporis (84/1062, 7.9% - 95% CI 6.4–9.7%), pyoderma (82/1062, 7.7% - 95% CI 6.2–9.5%) and scabies (56/1062. 5.2% - 95%CI 4.0–6.8%). 320 children were enrolled in the wet season survey of whom 121 (37.8%) had at least one skin problem. Tinea capitis remained the most common diagnosis (79/320, 24.7% - 95% CI 20.1–29.9%), followed by pyoderma (38/320, 11.9% - 95% CI 8.6–16.1%), tinea corporis (23/320, 7.2% - 95% 4.7–10.7%) and scabies (6/320, 1.9% - 95% CI 0.8–4.2%).ConclusionsOur study, which utilised robust population-based cluster random sampling methodology, demonstrates the substantial disease burden caused by common communicable dermatoses in this setting. Given these findings, there is a need to consider common dermatoses as part of Universal Health Coverage to deliver ‘skin-health for all’.

Workshop: Predictors and developmental timing of mental health problems among sexual minority individuals

Abstract As consistently shown across studies from various parts of the world, sexual minority individuals (e.g., those identifying as lesbian, gay, and bisexual [LGB]) are significantly at a higher risk for depression, anxiety, and suicidal thoughts and behavior when compared to heterosexuals. The increased risk for poor mental health among sexual minority populations is believed to be a consequence of LGB individuals’ increased exposure to specific social stressors related to navigating a stigmatized minority identity. Studies trying to explain health inequalities based on sexual orientation have mainly focused on so-called minority stress processes, such as discrimination, internalized homophobia, expectations of rejection, and stress of concealing one’s sexual orientation. This workshop will give examples of studies from various European countries on mental health predictors and trajectories by using various approaches such as population-based sampling, longitudinal data collection, and comprehensive theoretical frameworks. Dr. Gemma Lewis (University College London, UK) will present results showing that sexual orientation-based disparities in mental health are present already in early adolescence and increase throughout the school years. Arjan van der Star (Karolinska Institutet, Sweden) will present population-based data suggesting that openness about sexual orientation is not directly linked to lower risk of depression among sexual minorities, but is instead dependent on access to social support. Conor Mahon (Dublin City University, Ireland) will present results showing minority stressors as predictors of social anxiety among sexual minority men. Associate professor John Pachankis (Yale University, USA) will present results showing that, in addition to increased exposure to social stressors, barriers to societal integration can partially explain the elevated risk of suicidality among sexual minorities. Key messages Sexual minorities are a higher risk of mental health problems, such as depression, social anxiety, and suicidality, as compared to heterosexuals and these disparities can be identified early in life. Sexual orientation-based mental health disparities seem to be based both on disproportionate stigma-related stress and a higher prevalence of general risk factors for poor mental health.