Probability in Diagnostic Thinking

2019 ◽  
pp. 83-100
Author(s):  
Cym Anthony Ryle
Keyword(s):  
Risk Factors ◽  
Population Based ◽  
Diagnostic Reasoning ◽  
Individual Risk ◽  
Diagnostic Process ◽  
Test Results ◽  
Medically Unexplained ◽  
Individual Risk Factors ◽  
Diagnostic Thinking ◽  
Early Phases

This chapter observes that diagnostic reasoning involves both informal and mathematical estimates of probability. It argues that intuitive estimates of the likelihood of disease are necessary in the early phases of the diagnostic process but notoriously inaccurate. It notes that formal calculations are not possible when the question is, What might be wrong with this person? but are much more accurate than intuition in estimating the probability that a specific disease is present. The chapter suggests that population-based calculations of the likelihood of disease may lead clinicians to play Russian roulette by proxy because individual variation and individual risk factors may alter that risk in a given patient. It refers to evidence that many clinicians are inexpert in statistical methods. The chapter describes some basic statistical processes and their place in the clinical application of test results. It discusses the necessity and challenges of managing patients whose symptoms are medically unexplained.

scholarly journals Clustering of risk factors and the risk of incident cardiovascular disease in Asian and Caucasian populations: results from the Asia Pacific Cohort Studies Collaboration

BMJ Open ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. e019335 ◽  
Author(s):  
Sanne A E Peters ◽  
Xin Wang ◽  
Tai-Hing Lam ◽  
Hyeon Chang Kim ◽  
Suzanne Ho ◽  
...  
Keyword(s):  
Risk Factors ◽  
Cardiovascular Disease ◽  
Risk Factor ◽  
Cohort Studies ◽  
Cox Regression ◽  
Population Based ◽  
Asia Pacific ◽  
Individual Risk ◽  
Cvd Risk ◽  
Individual Risk Factors

ObjectiveTo assess the relationship between risk factor clusters and cardiovascular disease (CVD) incidence in Asian and Caucasian populations and to estimate the burden of CVD attributable to each cluster.SettingAsia Pacific Cohort Studies Collaboration.ParticipantsIndividual participant data from 34 population-based cohorts, involving 314 024 participants without a history of CVD at baseline.Outcome measuresClusters were 11 possible combinations of four individual risk factors (current smoking, overweight, blood pressure (BP) and total cholesterol). Cox regression models were used to obtain adjusted HRs and 95% CIs for CVD associated with individual risk factors and risk factor clusters. Population-attributable fractions (PAFs) were calculated.ResultsDuring a mean follow-up of 7 years, 6203 CVD events were recorded. The ranking of HRs and PAFs was similar for Australia and New Zealand (ANZ) and Asia; clusters including BP consistently showed the highest HRs and PAFs. The BP–smoking cluster had the highest HR for people with two risk factors: 4.13 (3.56 to 4.80) for Asia and 3.07 (2.23 to 4.23) for ANZ. Corresponding PAFs were 24% and 11%, respectively. For individuals with three risk factors, the BP–smoking–cholesterol cluster had the highest HR (4.67 (3.92 to 5.57) for Asia and 3.49 (2.69 to 4.53) for ANZ). Corresponding PAFs were 13% and 10%.ConclusionsRisk factor clusters act similarly on CVD risk in Asian and Caucasian populations. Clusters including elevated BP were associated with the highest excess risk of CVD.

scholarly journals The Association of Neighbourhood Built and Social Environment and Cancer: Evidence From Australia

2018 ◽  
Vol 4 (Supplement 2) ◽  
pp. 135s-135s
Author(s):  
Y. Feng ◽  
A. Elshaug
Keyword(s):  
Risk Factors ◽  
Social Environment ◽  
Cancer Incidence ◽  
National Level ◽  
Population Based ◽  
Individual Risk ◽  
Cancer Outcomes ◽  
Geographic Variations ◽  
Local Neighborhood ◽  
Individual Risk Factors

Background and context: Australia is among the worst countries in terms of cancer incidence and displays substantial variations in cancer outcomes across multiple geographic scales. Aim: This research project aims to examine how neighborhood social and environmental attributes interact with individual risk factors, affect cancer outcomes and contribute to the geographic variations in cancer outcomes. Specifically, it will answer the following research questions: What neighborhood built and social environment attributes are associated with individual health outcomes? How do neighborhood features influence cancer outcomes, at multiple geographic scales? At what geographical scales the variations in cancer outcomes are the most pronounced and how much is contributed by neighborhood attributes? What initiatives and guidelines should be developed and at what level: local neighborhood, regional, state, national level? Strategy/Tactics: Innovative geospatial techniques will be developed to analyze cancer risk factors and variations at multiple spatial levels utilizing population-based hospital inpatient data in NSW, Australia Program/Policy process: The study is the first population-based study evaluating how neighborhood influences cancer outcomes from multiple scales in the Australian context. The project has tangible potentials to be translated into initiatives and practices. This includes various levels such as local neighborhood, state and national level for the prevention and control of cancer and ultimately improve cancer outcomes in Australia. Outcomes: A large proportion of geographic variations in cancer outcomes are contributed by differences in the neighborhood built and social environment characteristics, which interact with individual risk factors and have synergistic effects on cancer outcomes. What was learned: Neighborhood physical and social environment has a strong effect on cancer outcomes. Through modification of neighborhood attributes, we can reduce the exposure to neighborhood risk factors and promote healthy lifestyle choices, which, in turn, reduce cancer incidence and improve survival rates. Effective initiatives and guidelines for cancer control should be developed and at all government levels including the local neighborhood, regional, state, national level.

Distribution of short and lifetime risks for cardiovascular disease in Italians

2011 ◽  
Vol 19 (4) ◽  
pp. 723-730 ◽  
Author(s):  
Augusto Di Castelnuovo ◽  
Simona Costanzo ◽  
Mariarosaria Persichillo ◽  
Marco Olivieri ◽  
Amalia de Curtis ◽  
...  
Keyword(s):  
Risk Factors ◽  
Cardiovascular Disease ◽  
Primary Prevention ◽  
Population Based ◽  
Lifetime Risk ◽  
Individual Risk ◽  
Cvd Risk ◽  
Cross Sectional ◽  
Individual Risk Factors ◽  
Short Time

Background: Guidelines for primary prevention recommend calculation of lifetime risk for cardiovascular disease (CVD) in addition to short-time risk. We aimed at evaluating the distribution of CVD lifetime risk and the percentage of Italians having low short-term, but high lifetime, risk. Design: Cross-sectional general population-based cohort study. Methods: We included 8,403 (46% men) cardiovascular disease-free individuals aged 35–50 years, among those randomly recruited in the framework of the MOLI-SANI cohort. Participants were stratified into three groups: low short-time (10-year) (≤3% and non diabetic)/low lifetime, low short-time/high lifetime, and high short-time risk. Short-time risk was evaluated by the equation provided by the Italian CUORE project. Lifetime risk was evaluated using the algorithm derived from the Framingham cohort. Results: High short-time risk was prevalent in 16% population (32% of men and 2% of women). Among individuals with low short-time risk, 80% had high lifetime risk (82% men and 78% women). The proportion of individuals with very low lifetime risk due to all optimal risk factors was 4.1% only (1.5% men and 6.3% women). Conclusions: A large proportion of Italian adults not qualified for CVD primary prevention because of their very low short-time predicted CVD risk, are in fact at high risk to develop a CVD event in their lifetime; therefore population-based approaches should be sought to modify the overall distribution of individual risk factors. These findings offer helpful information for policy makers involved in contrasting the burden of CVD, especially in women and young men.

scholarly journals Association of workplace and population characteristics with prevalence of hypertension among Brazilian industry workers: a multilevel analysis

BMJ Open ◽  
2017 ◽  
Vol 7 (8) ◽  
pp. e015755 ◽  
Author(s):  
Daniele B Vinholes ◽  
Sérgio L Bassanesi ◽  
Hilton de Castro Chaves Junior ◽  
Carlos Alberto Machado ◽  
Ione M F Melo ◽  
...  
Keyword(s):  
Risk Factors ◽  
Multilevel Analysis ◽  
Population Based ◽  
Cross Sectional Study ◽  
Individual Characteristics ◽  
Population Characteristics ◽  
Individual Risk ◽  
Small Companies ◽  
Cross Sectional ◽  
Individual Risk Factors

BackgroundExposure to risk factors for hypertension may be influenced by the characteristics of the workplace, where workers spend most of their daily time.ObjectivesTo evaluate the association between features of the companies, particularly the presence of facilities to provide meals, and of population characteristics and the prevalence of hypertension, taking into account individual risk factors for hypertension.Material and methodsThis multilevel analysis was based on a cross-sectional study with individual and company data from the SESI(Serviço Social da Indústria–Social Service of Industries)study and population-based data from the national census statistics. Workers aged ≥15 years were randomly selected from small (20–99), medium (100–499) and large (≥500 employees) companies per state using multistage sampling. Logistic regression was used to analyse the association between hypertension and individual, workplace and population variables, with odds ratios (ORs; 95% CI) adjusted for three-level variables.Results4818 Workers from 157 companies were interviewed and their blood pressure, weight and height were measured. Overall, 77% were men, aged 35.4 ±10.7 years, with 8.7 ±4.1 years of schooling and mostly worked in companies with a staff canteen (66%). Besides individual characteristics—being male, ageing, low schooling, alcohol abuse and higher BMI—a workplace with no staff canteen (OR=1.28; 95% CI 1.08 to 1.52), small companies (OR=1.31; 95% CI 1.07 to 1.60) and living in cities with higher economic inequality (OR=1.47; 95% CI 1.23 to 1.76) were associated with a higher risk for hypertension.ConclusionAmong Brazilian workers, the prevalence of hypertension is associated with individual risk factors, lack of a canteen at the workplace, small companies and higher economic inequalities of cities. These three-level characteristics help to interpret differences in the prevalence of hypertension between regions or countries.

A Model for Analyzing Suicide Prevention

Crisis ◽  
2000 ◽  
Vol 21 (2) ◽  
pp. 80-89 ◽  
Author(s):  
Maila Upanne
Keyword(s):  
Risk Factors ◽  
Theoretical Model ◽  
Protective Factors ◽  
Suicide Prevention ◽  
Suicide Risk ◽  
Practical Work ◽  
Individual Risk ◽  
Self Assessment ◽  
Prevention Project ◽  
Individual Risk Factors

This study monitored the evolution of psychologists' (n = 31) conceptions of suicide prevention over the 9-year course of the National Suicide Prevention Project in Finland and assessed the feasibility of the theoretical model for analyzing suicide prevention developed in earlier studies [ Upanne, 1999a , b ]. The study was formulated as a retrospective self-assessment where participants compared their earlier descriptions of suicide prevention with their current views. The changes in conceptions were analyzed and interpreted using both the model and the explanations given by the subjects themselves. The analysis proved the model to be a useful framework for revealing the essential features of prevention. The results showed that the freely-formulated ideas on prevention were more comprehensive than those evolved in practical work. Compared to the earlier findings, the conceptions among the group had shifted toward emphasizing a curative approach and the significance of individual risk factors. In particular, greater priority was focused on the acute suicide risk phase as a preventive target. Nonetheless, the overall structure of prevention ideology remained comprehensive and multifactorial, stressing multistage influencing. Promotive aims (protective factors) also remained part of the prevention paradigm. Practical working experiences enhanced the psychologists' sense of the difficulties of suicide prevention as well as their criticism and feeling of powerlessness.

scholarly journals Cardio-Metabolic Risk Factors in Scottish South Asian and Caucasian Youth

2021 ◽  
Vol 18 (9) ◽  
pp. 4667
Author(s):  
Meizi Wang ◽  
Jianhua Ying ◽  
Ukadike Chris Ugbolue ◽  
Duncan S. Buchan ◽  
Yaodong Gu ◽  
...  
Keyword(s):  
Risk Factors ◽  
Body Mass Index ◽  
Waist Circumference ◽  
Body Mass ◽  
South Asian ◽  
Metabolic Risk Factors ◽  
Individual Risk ◽  
Metabolic Risk ◽  
Asian Adolescents ◽  
Individual Risk Factors

(1) Background: Scotland has one of the highest rates of obesity in the Western World, it is well established that poor weight profiles, and particularly abdominal obesity, is strongly associated with Type II diabetes and cardiovascular diseases. Whether these associations are apparent in ethnic population groups in Scotland is unclear. The purpose of this study was to examine the associations between different measures of fatness with clustered cardio metabolic risk factors between Scottish South Asian adolescents and Scottish Caucasian adolescents; (2) Methods: A sample of 208 Caucasian adolescents and 52 South Asian adolescents participated in this study. Stature, waist circumference, body mass index, blood pressure, physical activity, and cardiovascular disease (CVD) risk were measured; (3) Results: Significant, partial correlations in the South Asian cohort between body mass index (BMI) and individual risk factors were generally moderate. However, correlations between Waist circumference (WC) and individual risk factors were significant and strong. In the Caucasian cohort, a significant yet weak correlation between WC and total cholesterol (TG) was noted although no other associations were evident for either WC or BMI. Multiple regression analysis revealed that both BMI and WC were positively associated with CCR (p < 0.01) in the South Asian group and with the additional adjustment of either WC or BMI, the independent associations with clustered cardio-metabolic risk (CCR) remained significant (p < 0.005); (4) Conclusions: No positive relationships were found between BMI, WC, and CCR in the Caucasian group. Strong and significant associations between measures of fatness and metabolic risk were evident in Scottish South Asian adolescents.

How Community and Individual Risk Factors Mutually Impact Youth’s Perceived Safety: A Syndemic Analysis Using Structural Equation Modeling

2021 ◽  
pp. 088626052110283
Author(s):  
Yingwei Yang ◽  
Karen D. Liller ◽  
Martha Coulter ◽  
Abraham Salinas-Miranda ◽  
Dinorah Martinez Tyson ◽  
...  
Keyword(s):  
Risk Factors ◽  
Structural Equation Modeling ◽  
Structural Equation ◽  
Community Safety ◽  
Equation Modeling ◽  
Individual Risk ◽  
Latent Factor ◽  
Community Factors ◽  
Individual Risk Factors ◽  
Syndemic Theory

The purpose of this study was to evaluate the mutual impact of community and individual factors on youth’s perceptions of community safety, using structural equation modeling (SEM) conceptualized by syndemic theory. This study used survey data collected from a county wide sample of middle and high school students (N=25,147) in West Central Florida in 2015. The outcome variable was youth’s perceptions of community safety. Predictors were latent individual and community factors constructed from 14 observed variables including gun accessibility, substance use, depressive symptoms, and multiple neighborhood disadvantage questions. Three structural equation models were conceptualized based on syndemic theory and analyzed in Mplus 8 using weighted least squares (WLS) estimation. Each model’s goodness of fit was assessed. Approximately seven percent of youth reported feeling unsafe in their community. After model modifications, the final model showed a good fit of the data and adhered to the theoretical assumption. In the final SEM model, an individual latent factor was implied by individual predictors measuring gun accessibility without adult’s permission (β=0.70), sadness and hopelessness (β=0.52), alcohol use (β=0.79), marijuana use (β=0.94), and illegal drug use (β=0.77). Meanwhile, a community latent factor was indicated by multiple community problems including public drinking (β=0.88), drug addiction (β=0.96), drug selling (β=0.97), lack of money (β=0.83), gang activities (β=0.90), litter and trash (β=0.79), graffiti (β=0.91), deserted houses (β=0.86), and shootings (β=0.93). A second-order syndemic factor that represented the individual and community factors showed a very strong negative association with youth’s safe perception (β=-0.98). This study indicates that individual risk factors and disadvantaged community conditions interacted with each other and mutually affected youth’s perceptions of community safety. To reduce these co-occurring effects and improve safe perceptions among youth, researchers and practitioners should develop and implement comprehensive strategies targeting both individual and community factors.

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