LEVEL (Logical Explanations & Visualizations of Estimates in Linear mixed models): recommendations for reporting multilevel data and analyses

Institute for Social and Health Studies (ISHS

Statistical Considerations when Communicating Health Risks: Experiences from Canada, Chile, Ecuador and England Facing COVID-19

Communicating statistics in health risk communication is a fundamental part of managing public health emergencies. Effective communication requires careful planning and the anticipation of possible information demands from the population. The information should be clear, relevant, easy to understand, timely, accurate and precise, allowing the public to make informed decisions about protective behaviours. COVID-19, being a new disease, with little known about its characteristics and effects, has challenged governments and healthcare systems in all countries. This article discusses the statistical issues involved, and the experiences of risk communication in four countries – Canada, Chile, Ecuador and England. These countries have communicated risks differently, partly because of their different healthcare systems, as well as socioeconomic, cultural and political realities. During a pandemic, health authorities and governments must step up to the challenge of communicating statistical information under pressure and with urgency, when little is known about the disease, the situation is dynamic and evolving, and the general public is gripped with fear and anxiety. This is in addition to the existing challenges relating to the generation of data of different quality by diverse sources, and a public with varying levels of statistical literacy. From a statistical perspective, communiqués about risks and numbers should convey the uncertainty there is about the information, the inherent variabilities in the system, the precision and accuracy of estimates and the assumptions behind projections. Complex technical concepts, such as ‘flattening the curve’, ‘range in risk estimates’ and ‘projected trends,’ should be explained

Does the association between birth weight and blood pressure increase with age? A longitudinal study in young adults

OBJECTIVES: To assess whether the association between birth weight and blood pressure (BP) increases with age using three different statistical methods. METHODS: A representative sample of 1232 study participants born between 1974-1978 in Limache, Chile were assessed in 2000-2002, of whom 796 were reassessed in 2010-2012. An 'amplification effect' was assessed by the change in the β coefficient in the two periods, the association between birth weight and the difference of BP overtime, and the interaction between birth weight and BP in the two periods. RESULTS: Birth weight was negatively associated with SBP in 2000-2002 (β = -2.46, 95% confidence interval (CI) -3.77 to -1.16) and in 2010-2012 (β = -3.64, 95% CI -5.20 to -2.08), and with DBP in 2000-2002 (β = -1.26, 95% CI -2.23 to -0.29) , and 2010-2012 (β = -1.64, 95% CI -2.84 to -0.45) after adjustment for sex, physical activity, and BMI. There was no association between birth weight and the difference in BP between the two periods or the interaction between birth weight, BP, and time interval. CONCLUSION: Birth weight is a factor associated with BP in adults. This association increased with age, but amplification was shown only with one of the three methods

Coordination of international multicenter studies: Governance and administrative structure

A well-conducted multicenter study needs to assure standardization, uniformity of procedures, high data quality, and collaboration across sites. This manuscript describes the organization and dynamics of multicenter studies, focusing on governance and administrative structures among countries of diverse cultures. the organizational structure of a multicenter study is described, and a system for oversight and coordination, along with roles and responsibilities of participants in the multicenter study, are presented. the elements of a governance document are also reviewed, along with guidelines and policies for effective collaboration. the experience of an ongoing multi-country collaboration, the World Studies of Abuse in the Family Environment (World-SAFE), illustrates the implementation of these guidelines. It is essential that multicenter studies have an objective coordinating center and that the investigators jointly develop a written governance document to enable collaboration and preserve collegiality among participating investigators. the English version of this paper is available too at: http://www.insp.mx/salud/index.html.Univ N Carolina, Chapel Hill, NC USAUniversidade Federal de São Paulo, Escola Paulista Med, São Paulo, BrazilUniv Philippines, Manila, PhilippinesUniv La Frontera, Temuco, ChileUniversidade Federal de São Paulo, Escola Paulista Med, São Paulo, BrazilWeb of Scienc

Reliability and validity of a nutrition and physical activity environmental self-assessment for child care

<p>Abstract</p> <p>Background</p> <p>Few assessment instruments have examined the nutrition and physical activity environments in child care, and none are self-administered. Given the emerging focus on child care settings as a target for intervention, a valid and reliable measure of the nutrition and physical activity environment is needed.</p> <p>Methods</p> <p>To measure inter-rater reliability, 59 child care center directors and 109 staff completed the self-assessment concurrently, but independently. Three weeks later, a repeat self-assessment was completed by a sub-sample of 38 directors to assess test-retest reliability. To assess criterion validity, a researcher-administered environmental assessment was conducted at 69 centers and was compared to a self-assessment completed by the director. A weighted kappa test statistic and percent agreement were calculated to assess agreement for each question on the self-assessment.</p> <p>Results</p> <p>For inter-rater reliability, kappa statistics ranged from 0.20 to 1.00 across all questions. Test-retest reliability of the self-assessment yielded kappa statistics that ranged from 0.07 to 1.00. The inter-quartile kappa statistic ranges for inter-rater and test-retest reliability were 0.45 to 0.63 and 0.27 to 0.45, respectively. When percent agreement was calculated, questions ranged from 52.6% to 100% for inter-rater reliability and 34.3% to 100% for test-retest reliability. Kappa statistics for validity ranged from -0.01 to 0.79, with an inter-quartile range of 0.08 to 0.34. Percent agreement for validity ranged from 12.9% to 93.7%.</p> <p>Conclusion</p> <p>This study provides estimates of criterion validity, inter-rater reliability and test-retest reliability for an environmental nutrition and physical activity self-assessment instrument for child care. Results indicate that the self-assessment is a stable and reasonably accurate instrument for use with child care interventions. We therefore recommend the Nutrition and Physical Activity Self-Assessment for Child Care (NAP SACC) instrument to researchers and practitioners interested in conducting healthy weight intervention in child care. However, a more robust, less subjective measure would be more appropriate for researchers seeking an outcome measure to assess intervention impact.</p

Exact correction factor for estimating the OR in the presence of sparse data with a zero cell in 2 × 2 tables

In case-control studies, odds ratios (OR) are calculated from 2 × 2 tables and in some instances, we observe small cell counts or zero counts in one of the cells. The corrections to calculate the ORs in the presence of empty cells are available in literature. Some of these include Yates continuity correction and Agresti and Coull correction. However, the available methods provided different corrections and the situations where each could be applied are not very apparent. Therefore, the current research proposes an iterative algorithm of estimating an exact (optimum) correction factor for the respective sample size. This was evaluated by simulating data with varying proportions and sample sizes. The estimated correction factor was considered after obtaining the bias, standard error of odds ratio, root mean square error and the coverage probability. Also, we have presented a linear function to identify the exact correction factor using sample size and proportion

Effects of ambient air pollution on obesity and ectopic fat deposition:a protocol for a systematic review and meta-analysis

Introduction - Globally, the prevalence of obesity tripled from 1975 to 2016. There is evidence that air pollution may contribute to the obesity epidemic through an increase in oxidative stress and inflammation of adipose tissue. However, the impact of air pollution on body weight at a population level remains inconclusive. This systematic review and meta-analysis will estimate the association of ambient air pollution with obesity, distribution of ectopic adipose tissue, and the incidence and prevalence of non-alcoholic fatty liver disease among adults. Methods and analysis.The study will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for conduct and reporting. The search will include the following databases: Ovid Medline, Embase, PubMed, Web of Science and Latin America and the Caribbean Literature on Health Sciences, and will be supplemented by a grey literature search. Each article will be independently screened by two reviewers, and relevant data will be extracted independently and in duplicate. Study-specific estimates of associations and their 95% Confidence Intervals will be pooled using a DerSimonian and Laird random-effects model, implemented using the RevMan software. The I2 statistic will be used to assess interstudy heterogeneity. The confidence in the body of evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.Ethics and disseminationAs per institutional policy, ethical approval is not required for secondary data analysis. In addition to being published in a peer-reviewed journal and presented at conferences, the results of the meta-analysis will be shared with key stakeholders, health policymakers and healthcare professionals.Prospero registration numberCRD42023423955

Socioeconomic status and risk of cardiovascular disease in 20 low-income, middle-income, and high-income countries: The prospective urban rural epidemiologic (PURE) study

Background: Socioeconomic status is associated with differences in risk factors for cardiovascular disease incidence and outcomes, including mortality. However, it is unclear whether the associations between cardiovascular disease and common measures of socioeconomic status-wealth and education-differ among high-income, middle-income, and low-income countries, and, if so, why these differences exist. We explored the association between education and household wealth and cardiovascular disease and mortality to assess which marker is the stronger predictor of outcomes, and examined whether any differences in cardiovascular disease by socioeconomic status parallel differences in risk factor levels or differences in management.Methods: In this large-scale prospective cohort study, we recruited adults aged between 35 years and 70 years from 367 urban and 302 rural communities in 20 countries. We collected data on families and households in two questionnaires, and data on cardiovascular risk factors in a third questionnaire, which was supplemented with physical examination. We assessed socioeconomic status using education and a household wealth index. Education was categorised as no or primary school education only, secondary school education, or higher education, defined as completion of trade school, college, or university. Household wealth, calculated at the household level and with household data, was defined by an index on the basis of ownership of assets and housing characteristics. Primary outcomes were major cardiovascular disease (a composite of cardiovascular deaths, strokes, myocardial infarction, and heart failure), cardiovascular mortality, and all-cause mortality. Information on specific events was obtained from participants or their family.Findings: Recruitment to the study began on Jan 12, 2001, with most participants enrolled between Jan 6, 2005, and Dec 4, 2014. 160 299 (87·9%) of 182 375 participants with baseline data had available follow-up event data and were eligible for inclusion. After exclusion of 6130 (3·8%) participants without complete baseline or follow-up data, 154 169 individuals remained for analysis, from five low-income, 11 middle-income, and four high-income countries. Participants were followed-up for a mean of 7·5 years. Major cardiovascular events were more common among those with low levels of education in all types of country studied, but much more so in low-income countries. After adjustment for wealth and other factors, the HR (low level of education vs high level of education) was 1·23 (95% CI 0·96-1·58) for high-income countries, 1·59 (1·42-1·78) in middle-income countries, and 2·23 (1·79-2·77) in low-income countries (pinteraction\u3c0·0001). We observed similar results for all-cause mortality, with HRs of 1·50 (1·14-1·98) for high-income countries, 1·80 (1·58-2·06) in middle-income countries, and 2·76 (2·29-3·31) in low-income countries (pinteraction\u3c0·0001). By contrast, we found no or weak associations between wealth and these two outcomes. Differences in outcomes between educational groups were not explained by differences in risk factors, which decreased as the level of education increased in high-income countries, but increased as the level of education increased in low-income countries (pinteraction\u3c0·0001). Medical care (eg, management of hypertension, diabetes, and secondary prevention) seemed to play an important part in adverse cardiovascular disease outcomes because such care is likely to be poorer in people with the lowest levels of education compared to those with higher levels of education in low-income countries; however, we observed less marked differences in care based on level of education in middle-income countries and no or minor differences in high-income countries.Interpretation: Although people with a lower level of education in low-income and middle-income countries have higher incidence of and mortality from cardiovascular disease, they have better overall risk factor profiles. However, these individuals have markedly poorer health care. Policies to reduce health inequities globally must include strategies to overcome barriers to care, especially for those with lower levels of education.Funding: Full funding sources are listed at the end of the paper (see Acknowledgments)

Factors associated with self-reported adherence to antiretroviral therapy in a Tanzanian setting

This study aimed to determine the level of antiretroviral (ART) adherence and factors associated with adherence among patients receiving free ART at one clinic in Tanzania. Adult patients were recruited into the cross-sectional study and completed a survey that included self-reported adherence over four days and over one month. Less than 95% adherence on either measure was considered “poor”. Factors associated with adherence in unadjusted analyses (α=0.10) were included in a logistic regression model. 340 patients participated in the study, and 5.9% (20/340) reported poor adherence. The final model found poor adherence associated with: being young (OR=4.03) or old (OR=6.68); having lower perceived quality of patient-provider interaction (OR=2.75); and ever missing a clinic appointment (OR=3.13). Results highlight good adherence, but suggest the importance of addressing: 1) age-specific challenges of adherence through counseling and support; 2) client-focused care and quality of patient-provider interaction; and 3) clinic appointment reminder systems