The Bradford Hill considerations on causality: a counterfactual perspective

AnchorFCI: harnessing genetic anchors for enhanced causal discovery of cardiometabolic disease pathways

Introduction

Cardiometabolic diseases, a major global health concern, stem from complex interactions of lifestyle, genetics, and biochemical markers. While extensive research has revealed strong associations between various risk factors and these diseases, latent confounding and limited causal discovery methods hinder understanding of their causal relationships, essential for mechanistic insights and developing effective prevention and intervention strategies.

Methods

We introduce anchorFCI, a novel adaptation of the conservative Really Fast Causal Inference (RFCI) algorithm, designed to enhance robustness and discovery power in causal learning by strategically selecting and integrating reliable anchor variables from a set of variables known not to be caused by the variables of interest. This approach is well-suited for studies of phenotypic, clinical, and sociodemographic data, using genetic variables that are recognized to be unaffected by these factors. We demonstrate the method's effectiveness through simulation studies and a comprehensive causal analysis of the 2015 ISA-Nutrition dataset, featuring both anchorFCI for causal discovery and state-of-the-art effect size identification tools from Judea Pearl's framework, showcasing a robust, fully data-driven causal inference pipeline.

Results

Our simulation studies reveal that anchorFCI effectively enhances robustness and discovery power while handles latent confounding by integrating reliable anchor variables and their non-ancestral relationships. The 2015 ISA-Nutrition dataset analysis not only supports many established causal relationships but also elucidates their interconnections, providing a clearer understanding of the complex dynamics and multifaceted nature of cardiometabolic risk.

Discussion

AnchorFCI holds significant potential for reliable causal discovery in complex, multidimensional datasets. By effectively integrating non-ancestral knowledge and addressing latent confounding, it is well-suited for various applications requiring robust causal inference from observational studies, providing valuable insights in epidemiology, genetics, and public health.

Pediatric acute kidney injury and adverse health outcomes: using a foundational framework to evaluate a causal link

Acute kidney injury (AKI) is a major global health problem, expensive to manage, and its associations with negative pediatric health outcomes have been clearly demonstrated. One of the most fundamental questions to consider as we use previous epidemiological information to advance research and care paradigms is the strength of the causal link between pediatric AKI and health outcomes. In this review, we apply the foundational framework of the Bradford Hill criteria to evaluate the extent to which a causal link exists between AKI and the associated adverse outcomes in children. Available data in children support a causal link between AKI and short-term outcomes including mortality, length of stay, and ventilation time. Clarifying the causal nature of longer term associations requires further high-quality observational studies in children, careful consideration of what defines the most meaningful and measurable longer term outcomes after pediatric AKI, and integration of evolving biological data related to mechanisms of disease. Preventing or mitigating AKI should lead to improved outcomes. Demonstrating such reversibility will solidify confidence in the causal relationship, improve child health, and highlight an aspect which is highly relevant to clinicians, scientists, and policy makers.

A scoping review of the clinical utility of adverse drug reaction causality analysis tools for use in the hospital setting

INTRODUCTION

Identification and monitoring of adverse drug reactions (ADRs) and interventions to reduce ADRs, is essential for patient safety in hospitals. Causality analysis (CA) is an approach that helps to determine a causal link between a medication and patient harm (i.e. an ADR). Whilst numerous CA tools exist, there is no gold standard.

AREAS COVERED

Five online databases were searched to identify studies that evaluated the potential clinical utility of CA tools for ADRs. CA tools were mapped against the Bradford Hill (BH) criteria and included if they adhered to the first seven criteria proposed by BH. Upon the database search, 550 studies were identified, with 41 studies being selected that looked at tools mapped to BH. Thirty-four different CA tools were identified in the included studies.

EXPERT OPINION

Naranjo and WHO-UMC were the most reported CA tools for studies examining inter-rater and intra-rater reliability. Naranjo commonly received a 'fair' agreement level while WHO-UMC received a 'substantial' agreement level between raters. Along with kappa statistics, time using the CA tool was also analyzed; with WHO-UMC being the most time-efficient. There does not appear to be one CA tool that can be applied universally to pharmacovigilance efforts in hospital in-patient settings.

Applying Bradford Hill to assessing causality in systematic reviews: A transparent approach using process tracing

BACKGROUND

Bradford Hill (BH) viewpoints are widely used to assess causality in systematic reviews, but their application has often lacked reproducibility. We describe an approach for assessing causality within systematic reviews ('causal' reviews), illustrating its application to the topic of income inequality and health. Our approach draws on principles of process tracing, a method used for case study research, to harness BH viewpoints to judge evidence for causal claims.

METHODS

In process tracing, a hypothesis may be confirmed by observing highly unique evidence and disconfirmed by observing highly definitive evidence. We drew on these principles to consider the value of finding supportive or contradictory evidence for each BH viewpoint characterised by its uniqueness and definitiveness.

RESULTS

In our exemplar systematic review, we hypothesised that income inequality adversely affects self-rated health and all-cause mortality. BH viewpoints 'analogy' and 'coherence' were excluded from the causal assessment because of their low uniqueness and low definitiveness. The 'experiment' viewpoint was considered highly unique and highly definitive, and thus could be particularly valuable. We propose five steps for using BH viewpoints in a 'causal' review: (1) define the hypothesis; (2) characterise each viewpoint; (3) specify the evidence expected for each BH viewpoint for a true or untrue hypothesis; (4) gather evidence for each viewpoint (e.g., systematic review meta-analyses, critical appraisal, background knowledge); (5) consider if each viewpoint was met (supportive evidence) or unmet (contradictory evidence).

CONCLUSIONS

Incorporating process tracing has the potential to provide transparency and structure when using BH viewpoints in 'causal' reviews.

Investigation of the Link Between Food Assistance Programs and Physical Activity Among Children and Adolescents

BACKGROUND

While the direct benefits of food assistance programs are well-documented, there is a need to explore indirect benefits like increased physical activity. This study examined whether participation in the Supplemental Nutrition Assistance Program (SNAP) was associated with improved physical activity levels in children and adolescents aged 2-17 in the United States during 2017-2018. Study Design: A cross-sectional study.

METHODS

This cross-sectional study used a subset of National Health and Nutrition Examination Survey (NHANES) data (n=2620). In the NHANES 2017-2018 dataset, physical activity was measured through self-report questionnaires, which captured participants' frequency, duration, and intensity of various activities. We used weighted logistic regression and the Hosmer - Lemeshow - Sturdivant forward model - building strategy to investigate this hypothesized association using SAS version 9.4.

RESULTS

In the adjusted model, controlling for the other variables in the model, we found that children and adolescents from households that had received SNAP/Food Stamps had 1.53 times higher odds (odds ratio [OR]=1.53, 95% CI: 1.24-1.89) of achieving the recommended guidelines of 60 minutes of daily physical activity compared to those who had not received benefits. Each additional year of age resulted in 0.82 times lower odds (OR=0.82; 95% CI: 0.79, 0.85) of meeting the recommended amounts of physical activity. Additionally, each unit increase in BMI was associated with 0.96 times lower odds (OR=0.96, 95% CI: 0.93, 0.98) of engaging in recommended physical activity.

CONCLUSION

These findings suggest that participation in the SNAP/Food Stamps program may indirectly benefit participants by increasing physical activity levels.

The database makes the poison: How the selection of datasets in QSAR models impacts toxicant prediction of higher tier endpoints

As the United States and the European Union continue their steady march towards the acceptance of new approach methodologies (NAMs), we need to ensure that the available tools are fit for purpose. Critics will be well-positioned to caution against NAMs acceptance and adoption if the tools turn out to be inadequate. In this paper, we focus on Quantitative Structure Activity-Relationship (QSAR) models and highlight how the training database affects quality and performance of these models. Our analysis goes to the point of asking, "are the endpoints extracted from the experimental studies in the database trustworthy, or are they false negatives/positives themselves?" We also discuss the impacts of chemistry on QSAR models, including issues with 2-D structure analyses when dealing with isomers, metabolism, and toxicokinetics. We close our analysis with a discussion of challenges associated with translational toxicology, specifically the lack of adverse outcome pathways/adverse outcome pathway networks (AOPs/AOPNs) for many higher tier endpoints. We recognize that it takes a collaborate effort to build better and higher quality QSAR models especially for higher tier toxicological endpoints. Hence, it is critical to bring toxicologists, statisticians, and machine learning specialists together to discuss and solve these challenges to get relevant predictions.

Hematological malignancy-associated pyoderma gangrenosum: evaluating the magnitude of the association

Background

Hematologic malignancies (HMs) are well-known underlying comorbidities of pyoderma gangrenosum (PG). However, studies quantifying the likelihood of PG after HMs are yet to be performed.

Objective

To investigate the bidirectional association between PG and several HMs, namely acute leukemia, chronic leukemia, Hodgkin lymphoma, non-Hodgkin lymphoma, and multiple myeloma.

Methods

A population-based retrospective cohort study was conducted to study the risk of HMs in patients with PG (n = 302) as compared to age-, sex-and ethnicity-matched control subjects (n = 1,799). A case-control design was used to estimate the likelihood of PG in individuals with a preexisting history of HMs. Adjusted hazard ratios (HRs) and adjusted odds ratios (ORs) were estimated by Cox regression and logistic regression, respectively.

Results

The prevalence of preexisting HM was higher in patients with PG than in controls (6.7% vs. 0.9%, respectively). The likelihood of having PG was significantly greater among patients with a history of HM (adjusted OR, 7.88; 95% CI, 3.85-16.15; p < 0.001), particularly during the first year following the diagnosis. This association was significant for acute leukemia, chronic leukemia, non-Hodgkin lymphoma, and multiple myeloma but not for Hodgkin lymphoma. The incidence rate of HM was 3.3 (95% CI, 1.2-7.4) and 1.6 (95% CI, 0.9-2.6)/1,000 person-years among patients with PG and controls, respectively. Relative to controls, patients with PG were not more likely to develop subsequent HM (adjusted HR, 2.22; 95%CI, 0.77-6.45; p = 0.142). Compared to other patients with PG, those with HM-associated PG experienced an increased all-cause mortality rate (adjusted HR, 2.19; 95%CI, 1.09-4.40; p = 0.028).

Conclusion

HM, particularly acute leukemia and multiple myeloma, are associated with an elevated likelihood of provoking PG.

Association between myasthenia gravis and Alzheimer's disease

INTRODUCTION

Myasthenia gravis (MG) and Alzheimer's disease (AD) are two of the most important diseases where the dysregulation of acetylcholine activity plays a crucial role. In the first, this dysregulation happens at the level of the neu-romuscular junction and in the second, in the central nervous system (CNS).

AIM

To analyze the possible relationship between these two pathologies, analyzing the prevalence and the odds ratio of AD within patients previously diagnosed with MG. We will compare these data with respect to the prevalence of AD in the general population.

PATIENTS AND METHODS

We examined the data obtained by the electronic medical records of patients in the health care system of Castilla La Mancha using the Natural Language Process provided by a clinical platform of artificial intelligence known as the Savana Manager?.

RESULTS

We identified 970,503 patients over the age of 60 years, of which 1,028 were diagnosed with MG. The proportion of the patients diagnosed with AD within this group (4.28%) was greater than the rest of the population (2.82%) (p = 0,0047) with an odds ratio of 1.54 (confidence interval at 95% 1.13-2.08; p = 0.0051) without finding significant differences in the bivariate analysis for the rest of the most important actual known risk factors for AD.

CONCLUSION

Our results suggest that there might be an increase in the prevalence of AD in patients previously diagnosed with MG.

Knowledge, Attitudes, Practices, and Acceptability of Medical Male Circumcision among Males in Traditionally Circumcising Rural Communities of Alfred Nzo District, Eastern Cape, South Africa

Male circumcision (MC) reduces HIV transmission risk by up to 60% in heterosexual men. However, uptake of medical male circumcision (MMC) is low in traditionally circumcising communities of South Africa. We assessed knowledge, attitudes, and practices to identify factors predicting acceptability of MMC among males in the Alfred Nzo District. A cross-sectional study was conducted among males aged 15-49 years in this district. Logistic regression was used to identify factors predicting acceptability of MMC. We interviewed 343 males who had a median age of 19 years (interquartile range (IQR): 16-25 years). Of these, 77% (95% confidence interval (CI): 72-82) were circumcised: 77% (95% CI: 71-82) were circumcised in a traditional setting and 21% (95% CI: 16-26) in a medical setting. The median score of knowledge about the benefits of MMC was 62.5% (IQR: 37.5-75.0), with 59% (95% CI: 53-64) demonstrating a positive attitude towards MMC and 68% (95% CI: 63-73) accepting involvement of health workers in MC. Excellent knowledge (adjusted odds ratio (aOR): 3.07, 95% CI: 0.99-9.58, p = 0.053), awareness (aOR: 3.26, 95% CI: 1.08-9.86, p = 0.037), and positive attitude towards MMC (aOR: 2.35, 95% CI: 1.30-4.25, p = 0.005) were associated with acceptability of MMC. Participants demonstrated good knowledge and acceptance of the MMC programme. Knowledge, attitude, and awareness were significant predictors of MMC acceptability.

Drawing causal inferences from randomized controlled trials in psychotherapy research

OBJECTIVE

Randomized control trials (RCTs) have played a critical role in psychotherapy research. This article discusses RCTs in the context of the criteria for drawing causal inferences in psychotherapy and intervention research more generally. The article also highlights underused variations of RCTs and how they not only establish causal relations but also address critical questions that can improve our intervention portfolio and patient care.

CONCLUSION

Random assignment is discussed in terms of what it can and cannot do in relation to drawing conclusions about the effects of interventions. Finally, RCTs are examined in the context of multiple questions that can guide therapy research, improve patient care, and develop treatments that reach people in need of psychological services.

Causality in psychotherapy research: Towards evidential pluralism

Identifying causal relationships is at the heart of all scientific inquiry, and a means to evidence base practices and to guide policymaking. However, being aware of the complexities of interactions and relationships, scientists and academics are cautious about claiming causality. Researchers applying methods that deviate from the experimental design generally abstain from causal claims, reserving them for designs that adhere to the evidential ideals of empiricism (e.g., RCTs), motivated by the Humean conceptions of causality. Accordingly, results from other designs are ascribed lower explanatory power and scientific status. We discuss the relevance of also other perspectives of causality, such as dispositionalism and the power perspectives of various realist approaches, which emphasize intrinsic properties and contextual variations, as well as an inferentialist/epistemic approach that advocates causal explanations in terms of inferences and linguistic interaction. The discussion will be illustrated by the current situation within psychotherapy research and the APA Policy Statement on Evidence-Based Practice. The distinction between difference-making and causal production will be proposed as a possible means to evaluate the relevance of designs. We conclude that clarifying causal relationships is an ongoing process that requires the use of various designs and methods and advocate a stance of evidential pluralism.

The role of income and frequency of dental visits in the relationship between dental sealant use and resin fillings after extended coverage: a retrospective cohort study

BACKGROUND

Prevention and treatment services use is closely associated with socioeconomic factors, such as income. This study aimed to investigate the relationship between implementing the sealant program and resin fillings restoration and to explore the role of income and frequency of dental visits in this relationship.

METHODS

This retrospective cohort study used the cohort database from the National Health Information Database of the National Health Insurance Service. The study population comprised 494,731 children born in 2007. A logistic regression model for the experience of resin fillings and a linear regression model for weighted utilization of them were used to identify the independent effects of dental sealants, income, and frequency of dental visits. All analyses were conducted using the SAS Enterprise Guide version 7.1 (SAS Institute Inc., Cary, NC, USA).

RESULTS

The ratio based on income level was almost proportional in all groups except the medical aid group, which had a rate as high as that of the wealthier group. Children without sealants were 1.05 times more likely to have resin fillings than others after adjusting for income level and frequency of visiting dental clinics in the final model. However, an opposite relationship between sealant experiences and resin fillings was observed in the previous model without dental visits. The gap in the weighted resin filling scores according to socioeconomic variables showed a similar tendency.

CONCLUSIONS

Income and frequency of dental visits might be confounding factors for the relationship between dental sealant and resin fillings. It is necessary to consider the complex relationship between socioeconomic indicators and service use while studying oral health inequality.

Association of Generation and Group Size With the Usage of a Mobile Health App in Thailand: Secondary Analysis of the ThaiSook Cohort Study

BACKGROUND

In Thailand, The National Science and Technology Development Agency developed ThaiSook, a behavior-tracking app, to promote healthy lifestyles. The Faculty of Medicine, Prince of Songkla University (MED PSU)×ThaiSook Healthier Challenge encouraged employees to use the app over a 28-day period (from July 11 to August 7, 2022). Until recently, no previous studies have examined the association of generations and group sizes with mobile health (mHealth) app use. Understanding these relationships can inform the design of effective mHealth interventions and facilitate targeted interventions.

OBJECTIVE

This study aimed to (1) compare the overall app usage and logging function across different generations and group sizes and (2) describe the demographic characteristics of the participants of the MED PSU×ThaiSook Healthier Challenge.

METHODS

We conducted a secondary data analysis of the data from the ThaiSook prospective cohort study. Data were collected through the app and comprised demographic characteristics (ie, age, sex, weight, height, and group size) and behaviors (ie, water consumption, fruit and vegetable consumption, sleep hours, and exercise). The outcomes consisted of users who used the app for at least 80% of the participation period (≥23 days). Bivariate tests (Pearson chi-square test for categorical variables and Mann-Whitney U and Kruskal-Wallis tests for continuous variables) were conducted over sex, generations, initial BMI, and group size. Finally, multiple logistic regression models were used to examine the relationship between the independent variables used by the ThaiSook app and consistent users who had used the app for at least 80% of the participation period.

RESULTS

Of the 827 participants, most were female (734/827, 88.8%), belonged to a medium-sized group of 6-10 members (479/827, 57.9%), and belonged to generation Y (377/761, 49.5%). Multivariate analysis revealed that the overall app usage was 2.09 times higher in women than in men (adjusted odds ratio [AOR] 2.09, 95% CI 1.27-3.44). The older generations used all logging functions more frequently than did generation Y (baby boomers AOR 2.54, 95% CI 1.31-4.92; generation X AOR 1.96, 95% CI 1.42-2.72). The use of all logging functions was higher among participants belonging to larger groups than among those belonging to smaller groups (large groups AOR 2.85, 95% CI 1.58-5.16; medium groups AOR 2.06, 95% CI 1.47-2.88). Water logging was most used (806/827, 97.5% participants), followed by food, sleep, and workout logging.

CONCLUSIONS

The MED PSU×ThaiSook Healthier Challenge participants were mostly females from generation Y and medium-sized groups. Water logging was most frequently used, followed by fruit and vegetable logging. The results indicate that generation and group size were significantly associated with consistent and daily usage (P<.05). Older generations and larger groups engaged with the app more consistently than younger generations and smaller groups and individuals.

Maternal Exposure to Potentially Toxic Metals and Birth Weight: Preliminary Results from the DSAN-12M Birth Cohort in the Recôncavo Baiano, Brazil

Prenatal exposure to potentially toxic metals (PTM) may impair fetal growth (FG). We investigated the relationship between maternal exposure to lead (Pb), cadmium (Cd) and manganese (Mn) and birth weight (BW) of 74 newborns. Blood was collected during the second trimester of pregnancy to determine Pb (PbB) and Cd (CdB), while hair (MnH) and toenails (MnTn) were used for Mn. Samples were analyzed by graphite furnace atomic absorption spectrophotometry (GFAAS). Sociodemographic and BW data were collected from questionnaires and maternity records, respectively. The medians (P25th-P75th) of PbB, CdB, MnH, and MnTn were, respectively, 0.9 (0.5-1.8) µg/dL; 0.54 (0.1-0.8) µg/L; 0.18 (0.1-0.4) µg/g; and 0.65 (0.37-1.22) µg/g. The means (standard deviation) of birth weight according to sex were 3067 (426.3) and 3442 (431) grams, respectively, for girls and boys. MnTn presented an inverse correlation with the BW/gestational age ratio for girls (rho = -0.478; p = 0.018), suggesting the effect of sex modification. Although BW correlation with CdB was not statistically significant, hierarchical linear regression (beta = -2.08; 95% CI-4.58 to 0.41) suggested a fetotoxic effect. These results confirmed the threat PTMs may represent and the need for more extensive research to elucidate their role in inadequate FG in developing countries.

Intractable postural hypotension resulting from cervical pseudomeningocele after a posterior cervical spinal surgery: a case report

INTRODUCTION

Postural hypotension (PH) is common in patients with spinal cord injury (SCI), especially those with tetraplegia. To effectively treat PH, identifying and eliminating treatable predisposing factors of PH are prerequisites before applying any interventions.

CASE PRESENTATION

We report a patient with post-acute cervical SCI who suffered from intractable PH resulting from pseudomeningocele causing unfavorable rehabilitation outcomes. A previously healthy 34-year-old man with complete C6 SCI resulting from C6-C7 fracture dislocation developed PH in the first week of the rehabilitation program. No specific predisposing factors including anemia, hyponatremia, and dehydration were identified. Non-pharmacological interventions and pharmacological treatment were administered to the patient without satisfactory result, causing a delay in rehabilitation progression. In the fourth week of rehabilitation program, a mass at the surgical site was detected. A cervical MRI revealed a large fluid collection at the posterior aspect of cervical spines with a size of 7.9 × 6.8 × 5.0 cm. A diagnosis of pseudomeningocele was made and surgical site debridement with closing dura by grafting was immediately conducted. One day after surgery, PH disappeared, and the patient could progress in his rehabilitation program and achieve his short-term goal within three weeks.

CONCLUSION

Pseudomeningocele could be one of the precipitating factors of PH in patients with tetraplegia. Healthcare providers should consider investigating pseudomeningocele in patients who have intractable and unexplainable PH.

Exploring risk transfer of human brucellosis in the context of livestock agriculture transition: A case study in Shaanxi, China

With the booming of worldwide agriculture intensification, brucellosis, one of the most neglected zoonotic diseases, has become an increasing challenge for global public health. Although the transmission patterns of human brucellosis (HB) have been studied in many regions, the dynamic transfer processes of risk and its driving factors remain poorly understood, especially in the context of agricultural intensification. This study attempted to explore the risk transfer of HB between the exact epidemic areas and the neighboring or distant low-risk areas to explain the impact of livestock agriculture intensification and foodborne infections on the transmission of HB in Shaanxi Province as a case study. We adopted multiple approaches, including test-based methods, model-based methods, and a geographical detector to detect the spatial-temporal dynamic changes of high-risk epidemic areas of HB at the county scale. We also quantitatively estimated how the related factors drove the risk transfer of the disease. Results confirmed the risk transfer pattern of HB with an expansion from north to south in Shaanxi Province and identified two primary transfer routes. In particular, in the traditional epidemic areas of the Shaanbei plateau, the farm agglomeration effect can significantly increase the risk of HB. Meanwhile, retail outlets for milk and dairy products were partially responsible for the foodborne infections of HB in the emerging epidemic areas of Xi'an. This study not only contributed helpful insights to support HB control and prevention in the rapid transition of livestock agriculture but also provided possible directions for further research on foodborne HB infections in urbanized areas.

Measuring clinical outcomes of highly multiplex molecular diagnostics for respiratory infections: A systematic review and conceptual framework

Objectives

To review methodologies and outcomes reporting among these studies and to develop a conceptual framework of outcomes to assist in guiding studies and production of clinical metrics.

Data sources

PubMed and Embase from January 1, 2012, thru December 1, 2021.

Study eligibility criteria

Studies evaluating highly multiplex molecular respiratory diagnostics and their impact on either clinical or economic outcomes.

Methods

A systematic literature review (SLR) of methodologies and outcomes reporting was performed. A qualitative synthesis of identified SLRs and associated primary studies was conducted to develop conceptual framework for outcomes.

Results

Ultimately, 4 systemic literature reviews and their 12 associated primary studies were selected for review. Most primary studies included patient outcomes focusing on antimicrobial exposure changes such as antibiotic (80%) and antiviral use (50%) or occupancy changes such as hospital length of stay (60%). Economic outcomes were infrequently reported, and societal outcomes, such as antibiotic resistance impact, were absent from the reviewed literature. Qualitative evidence synthesis of reported outcomes yielded a conceptual framework of outcomes to include operational, patient, economic, and societal domains.

Conclusions

Our review highlights the significant heterogeneity in outcomes reporting among clinical impact studies for highly multiplex molecular respiratory diagnostics. Furthermore, we developed a conceptual framework of outcomes domains that may act as a guide to improve considerations in outcomes selection and reporting when evaluating clinical impact of these tests. These improvements may be important in synthesizing the evidence for informing clinical decision making, guidelines, and financial reimbursement.

The methodologies to assess the effectiveness of non-pharmaceutical interventions during COVID-19: a systematic review

Non-pharmaceutical interventions, such as school closures and stay-at-home orders, have been implemented around the world to control the spread of SARS-CoV-2. Their effectiveness in improving health-related outcomes has been the subject of numerous empirical studies. However, these studies show fairly large variation among methodologies in use, reflecting the absence of an established methodological framework. On the one hand, variation in methodologies may be desirable to assess the robustness of results; on the other hand, a lack of common standards can impede comparability among studies. To establish a comprehensive overview over the methodologies in use, we conducted a systematic review of studies assessing the effectiveness of non-pharmaceutical interventions between January 1, 2020 and January 12, 2021 (n = 248). We identified substantial variation in methodologies with respect to study setting, outcome, intervention, methodological approach, and effectiveness assessment. On this basis, we point to shortcomings of existing studies and make recommendations for the design of future studies.

The association of six autoimmune bullous diseases with thyroid disorders: A population-based study

BACKGROUND

The association of autoimmune bullous diseases (AIBDs) with thyroid disorders remains to be profoundly investigated.

OBJECTIVE

To evaluate the epidemiological association between six AIBDs and thyroid disorders.

METHODS

A population-based cross-sectional study enrolled patients with bullous pemphigoid (BP), mucous membrane pemphigoid (MMP), epidermolysis bullosa acquisita (EBA), pemphigoid gestationis (PG), pemphigus vulgaris (PV), and pemphigus foliaceus (PF). Patients with these six AIBDs were compared with six age- and sex-matched control groups regarding the prevalence of thyroiditis and hyperthyroidism. Logistic regression was used to calculate the odds ratio (OR) and 95% confidence interval (CI) for thyroid disorders.

RESULTS

The study population included 1,743, 251, 106, 126, 860, and 103 patients with BP, MMP, EBA, PG, PV, and PF, respectively. The corresponding control groups consisted of 10,141, 1,386, 606, 933, 5,142, and 588 matched controls, respectively. A significant association was found between thyroiditis and BP (OR, 1.98; 95% CI, 1.18-3.35; P=0.010), MMP (OR, 7.02; 95% CI, 1.87-26.33; P=0.004), and PV (OR, 2.73; 95% CI, 1.45-5.15; P=0.002). With regard to hyperthyroidism, PF was the only AIBD to demonstrate significant comorbidity (OR, 2.42; 95% CI, 1.13-5.21; P=0.024). EBA and PG were not found to cluster with any of the investigated thyroid conditions.

CONCLUSION

Patients with BP, MMP, PV, and PF experience an elevated burden of thyroid disorders. Patients with these AIBDs presenting with suggestive symptoms may be carefully screened for comorbid thyroid disorders.

Functional connectivity drives stroke recovery: shifting the paradigm from correlation to causation

Stroke is a leading cause of disability, with deficits encompassing multiple functional domains. The heterogeneity underlying stroke poses significant challenges in the prediction of post-stroke recovery, prompting the development of neuroimaging-based biomarkers. Structural neuroimaging measurements, particularly those reflecting corticospinal tract injury, are well-documented in the literature as potential biomarker candidates of post-stroke motor recovery. Consistent with the view of stroke as a 'circuitopathy', functional neuroimaging measures probing functional connectivity may also prove informative in post-stroke recovery. An important step in the development of biomarkers based on functional neural network connectivity is the establishment of causality between connectivity and post-stroke recovery. Current evidence predominantly involves statistical correlations between connectivity measures and post-stroke behavioural status, either cross-sectionally or serially over time. However, the advancement of functional connectivity application in stroke depends on devising experiments that infer causality. In 1965, Sir Austin Bradford Hill introduced nine viewpoints to consider when determining the causality of an association: (i) strength; (ii) consistency; (iii) specificity; (iv) temporality; (v) biological gradient; (vi) plausibility; (vii) coherence; (viii) experiment; and (ix) analogy. Collectively referred to as the Bradford Hill Criteria, these points have been widely adopted in epidemiology. In this review, we assert the value of implementing Bradford Hill's framework to stroke rehabilitation and neuroimaging. We focus on the role of neural network connectivity measurements acquired from task-oriented and resting-state functional MRI, EEG, magnetoencephalography and functional near-infrared spectroscopy in describing and predicting post-stroke behavioural status and recovery. We also identify research opportunities within each Bradford Hill tenet to shift the experimental paradigm from correlation to causation.

Nutrient-sensing amyloid metastasis

Amyloids are organized suprastructural polypeptide arrangements. The prevalence of amyloid-related processes of pathophysiological relevance has been linked to aging-related degenerative diseases. Besides the role of genetic polymorphisms on the relative risk of amyloid diseases, the contributions of nongenetic ontogenic cluster of factors remain elusive. In recent decades, mounting evidences have been suggesting the role of essential micronutrients, in particular transition metals, in the regulation of amyloidogenic processes, both directly (such as binding to amyloid proteins) or indirectly (such as regulating regulatory partners, processing enzymes, and membrane transporters). The features of transition metals as regulatory cofactors of amyloid proteins and the consequences of metal dyshomeostasis in triggering amyloidogenic processes, as well as the evidences showing amelioration of symptoms by dietary supplementation, suggest an exaptative role of metals in regulating amyloid pathways. The self- and cross-talk replicative nature of these amyloid processes along with their systemic distribution support the concept of their metastatic nature. The role of amyloidosis as nutrient sensors would act as intra- and transgenerational epigenetic metabolic programming factors determining health span and life span, viability, which could participate as an evolutive selective pressure.

Visual Analytics: A Method to Explore Natural Histories of Oral Epithelial Dysplasia

Risk assessment and follow-up of oral potentially malignant disorders in patients with mild or moderate oral epithelial dysplasia is an ongoing challenge for improved oral cancer prevention. Part of the challenge is a lack of understanding of how observable features of such dysplasia, gathered as data by clinicians during follow-up, relate to underlying biological processes driving progression. Current research is at an exploratory phase where the precise questions to ask are not known. While traditional statistical and the newer machine learning and artificial intelligence methods are effective in well-defined problem spaces with large datasets, these are not the circumstances we face currently. We argue that the field is in need of exploratory methods that can better integrate clinical and scientific knowledge into analysis to iteratively generate viable hypotheses. In this perspective, we propose that visual analytics presents a set of methods well-suited to these needs. We illustrate how visual analytics excels at generating viable research hypotheses by describing our experiences using visual analytics to explore temporal shifts in the clinical presentation of epithelial dysplasia. Visual analytics complements existing methods and fulfills a critical and at-present neglected need in the formative stages of inquiry we are facing.

Breast Cancer Risk and Human Papillomavirus Infection: A Bradford Hill Criteria Based Evaluation

BACKGROUND

The association between human papillomavirus (HPV) and human breast cancer (BC) has already been thoroughly studied worldwide with contradictory findings. Although the researchers have tried to minimize the conflict using statistical meta-analysis, because of its shortcomings, there is still a need to evaluate the correlation between HPV and BC using any additional method.

OBJECTIVES

This study was launched to investigate the correlation between HPV and BC through the application of Bradford Hill criteria postulates.

METHODS

Population-wide studies associating HPV with BC were searched using the PubMed database. Then, the information of HPV burden in BC, normal/benign samples was analyzed, and ultimately Bradford Hill criteria postulates were applied on the collected evidence to explore the relationship between HPV and BC. In addition, to make the outcomes more authentic, we also reviewed the methodologies of previous studies to address the propensity of false results.

RESULTS

After a careful evaluation of the obtained data against major Bradford Hill criteria postulates, it was noted that all these postulates including strength, consistency, biological gradient, temporality, plausibility, experiment, specificity, and analogy were not fulfilled.

CONCLUSION

The results of the present study have failed to establish a casual association between HPV and BC rather suggested HPV as a cause-effective agent or at least a co-participant in the pathogenesis of BC. The weakness of association especially the low level of consistency across studies, and the lack of specificity of effect, there is a need for more experiments concerning Bradford Hill criteria postulates.

Risk and protective factors for mental disorders beyond genetics: an evidence-based atlas

Decades of research have revealed numerous risk factors for mental disorders beyond genetics, but their consistency and magnitude remain uncer-tain. We conducted a "meta-umbrella" systematic synthesis of umbrella reviews, which are systematic reviews of meta-analyses of individual studies, by searching international databases from inception to January 1, 2021. We included umbrella reviews on non-purely genetic risk or protective factors for any ICD/DSM mental disorders, applying an established classification of the credibility of the evidence: class I (convincing), class II (highly suggestive), class III (suggestive), class IV (weak). Sensitivity analyses were conducted on prospective studies to test for temporality (reverse causation), TRANSD criteria were applied to test transdiagnosticity of factors, and A Measurement Tool to Assess Systematic Reviews (AMSTAR) was employed to address the quality of meta-analyses. Fourteen eligible umbrella reviews were retrieved, summarizing 390 meta-analyses and 1,180 associations between putative risk or protective factors and mental disorders. We included 176 class I to III evidence associations, relating to 142 risk/protective factors. The most robust risk factors (class I or II, from prospective designs) were 21. For dementia, they included type 2 diabetes mellitus (risk ratio, RR from 1.54 to 2.28), depression (RR from 1.65 to 1.99) and low frequency of social contacts (RR=1.57). For opioid use disorders, the most robust risk factor was tobacco smoking (odds ratio, OR=3.07). For non-organic psychotic disorders, the most robust risk factors were clinical high risk state for psychosis (OR=9.32), cannabis use (OR=3.90), and childhood adversities (OR=2.80). For depressive disorders, they were widowhood (RR=5.59), sexual dysfunction (OR=2.71), three (OR=1.99) or four-five (OR=2.06) metabolic factors, childhood physical (OR=1.98) and sexual (OR=2.42) abuse, job strain (OR=1.77), obesity (OR=1.35), and sleep disturbances (RR=1.92). For autism spectrum disorder, the most robust risk factor was maternal overweight pre/during pregnancy (RR=1.28). For attention-deficit/hyperactivity disorder (ADHD), they were maternal pre-pregnancy obesity (OR=1.63), maternal smoking during pregnancy (OR=1.60), and maternal overweight pre/during pregnancy (OR=1.28). Only one robust protective factor was detected: high physical activity (hazard ratio, HR=0.62) for Alzheimer's disease. In all, 32.9% of the associations were of high quality, 48.9% of medium quality, and 18.2% of low quality. Transdiagnostic class I-III risk/protective factors were mostly involved in the early neurodevelopmental period. The evidence-based atlas of key risk and protective factors identified in this study represents a benchmark for advancing clinical characterization and research, and for expanding early intervention and preventive strategies for mental disorders.

Assessing causality in epidemiology: revisiting Bradford Hill to incorporate developments in causal thinking

The nine Bradford Hill (BH) viewpoints (sometimes referred to as criteria) are commonly used to assess causality within epidemiology. However, causal thinking has since developed, with three of the most prominent approaches implicitly or explicitly building on the potential outcomes framework: directed acyclic graphs (DAGs), sufficient-component cause models (SCC models, also referred to as 'causal pies') and the grading of recommendations, assessment, development and evaluation (GRADE) methodology. This paper explores how these approaches relate to BH's viewpoints and considers implications for improving causal assessment. We mapped the three approaches above against each BH viewpoint. We found overlap across the approaches and BH viewpoints, underscoring BH viewpoints' enduring importance. Mapping the approaches helped elucidate the theoretical underpinning of each viewpoint and articulate the conditions when the viewpoint would be relevant. Our comparisons identified commonality on four viewpoints: strength of association (including analysis of plausible confounding); temporality; plausibility (encoded by DAGs or SCC models to articulate mediation and interaction, respectively); and experiments (including implications of study design on exchangeability). Consistency may be more usefully operationalised by considering an effect size's transportability to a different population or unexplained inconsistency in effect sizes (statistical heterogeneity). Because specificity rarely occurs, falsification exposures or outcomes (i.e., negative controls) may be more useful. The presence of a dose-response relationship may be less than widely perceived as it can easily arise from confounding. We found limited utility for coherence and analogy. This study highlights a need for greater clarity on BH viewpoints to improve causal assessment.

Assessing causality in epidemiology: revisiting Bradford Hill to incorporate developments in causal thinking

The nine Bradford Hill (BH) viewpoints (sometimes referred to as criteria) are commonly used to assess causality within epidemiology. However, causal thinking has since developed, with three of the most prominent approaches implicitly or explicitly building on the potential outcomes framework: directed acyclic graphs (DAGs), sufficient-component cause models (SCC models, also referred to as 'causal pies') and the grading of recommendations, assessment, development and evaluation (GRADE) methodology. This paper explores how these approaches relate to BH's viewpoints and considers implications for improving causal assessment. We mapped the three approaches above against each BH viewpoint. We found overlap across the approaches and BH viewpoints, underscoring BH viewpoints' enduring importance. Mapping the approaches helped elucidate the theoretical underpinning of each viewpoint and articulate the conditions when the viewpoint would be relevant. Our comparisons identified commonality on four viewpoints: strength of association (including analysis of plausible confounding); temporality; plausibility (encoded by DAGs or SCC models to articulate mediation and interaction, respectively); and experiments (including implications of study design on exchangeability). Consistency may be more usefully operationalised by considering an effect size's transportability to a different population or unexplained inconsistency in effect sizes (statistical heterogeneity). Because specificity rarely occurs, falsification exposures or outcomes (i.e., negative controls) may be more useful. The presence of a dose-response relationship may be less than widely perceived as it can easily arise from confounding. We found limited utility for coherence and analogy. This study highlights a need for greater clarity on BH viewpoints to improve causal assessment.

Importance of Molecular Data to Identify Fungal Plant Pathogens and Guidelines for Pathogenicity Testing Based on Koch's Postulates

Fungi are an essential component of any ecosystem, but they can also cause mild and severe plant diseases. Plant diseases are caused by a wide array of fungal groups that affect a diverse range of hosts with different tissue specificities. Fungi were previously named based only on morphology and, in many cases, host association, which has led to superfluous species names and synonyms. Morphology-based identification represents an important method for genus level identification and molecular data are important to accurately identify species. Accurate identification of fungal pathogens is vital as the scientific name links the knowledge concerning a species including the biology, host range, distribution, and potential risk of the pathogen, which are vital for effective control measures. Thus, in the modern era, a polyphasic approach is recommended when identifying fungal pathogens. It is also important to determine if the organism is capable of causing host damage, which usually relies on the application of Koch's postulates for fungal plant pathogens. The importance and the challenges of applying Koch's postulates are discussed. Bradford Hill criteria, which are generally used in establishing the cause of human disease, are briefly introduced. We provide guidelines for pathogenicity testing based on the implementation of modified Koch's postulates incorporating biological gradient, consistency, and plausibility criteria from Bradford Hill. We provide a set of protocols for fungal pathogenicity testing along with a severity score guide, which takes into consideration the depth of lesions. The application of a standard protocol for fungal pathogenicity testing and disease assessment in plants will enable inter-studies comparison, thus improving accuracy. When introducing novel plant pathogenic fungal species without proving the taxon is the causal agent using Koch's postulates, we advise the use of the term associated with the "disease symptoms" of "the host plant". Where possible, details of disease symptoms should be clearly articulated.

Medicolegal Causation Investigation of Bacterial Endocarditis Associated with an Oral Surgery Practice Using the INFERENCE Approach

Investigating causation is a primary goal in forensic/legal medicine, aiming to establish the connection between an unlawful/negligent act and an adverse outcome. In malpractice litigation involving a healthcare-associated infection due to a failure of infection prevention and control practices, the medicolegal causal analysis needs to quantify the individual causal probabilities to meet the evidentiary requirements of the court. In this paper, we present the investigation of the most probable cause of bacterial endocarditis in a patient who underwent an invasive procedure at a dental/oral surgical practice where an outbreak of bacterial endocarditis had already been identified by the state Department of Health. We assessed the probability that the patient’s endocarditis was part of the outbreak versus that it was an unrelated sporadic infection using the INFERENCE (Integration of Forensic Epidemiology and the Rigorous Evaluation of Causation Elements) approach to medicolegal causation analysis. This paper describes the step-by-step application of the INFERENCE approach to demonstrate its utility in quantifying the probability of causation. The use of INFERENCE provides the court with an evidence-based, transparent, and reliable guide to determine liability, causation, and damages.

The burden of neurological comorbidities in six autoimmune bullous diseases: a population-based study

BACKGROUND

Apart from bullous pemphigoid (BP), the association of other autoimmune bullous diseases (AIBDs) with neurological conditions is poorly understood.

OBJECTIVE

To estimate the association between a wide array of AIBDs and neurological conditions.

METHODS

A retrospective cross-sectional study recruited patients with BP, mucous membrane pemphigoid (MMP), epidermolysis bullosa acquisita (EBA), pemphigoid gestationis (PG), pemphigus vulgaris (PV) and pemphigus foliaceus (PF). These patients were compared with their age- and sex-matched control subjects with regard to the lifetime prevalence of Parkinson's disease (PD), Alzheimer's disease (AD), stroke, epilepsy and multiple sclerosis (MS). Logistic regression was used to calculate OR for specified neurological disorders.

RESULTS

The current study included 1743, 251, 106, 126, 860 and 103 patients diagnosed with BP, MMP, EBA, PG, PV and PF, respectively. These patients were compared with 10 141, 1386, 606, 933, 5142 and 588 matched controls, respectively. Out of the investigated neurological conditions, PD associated with BP (OR, 2.71; 95% CI, 2.19-3.35); AD with BP (OR, 2.11; 95% CI, 1.73-2.57), MMP (OR, 2.37; 95% CI, 1.03-5.47), EBA (OR, 6.00; 95% CI, 1.90-18.97) and PV (OR, 2.24; 95% CI, 1.40-3.60); stroke with BP (OR, 1.84; 95% CI, 1.55-2.19) and EBA (OR, 2.79; 95% CI, 1.11-7.01); and epilepsy with BP (OR, 2.18; 95% CI, 1.72-2.77) and PV (OR, 1.80; 95% CI, 1.19-2.73). MS did not significantly cluster with any of the six AIBDs.

CONCLUSION

In addition to BP, EBA and PV were found to cluster with neurological comorbidities. Patients with these AIBDs with compatible symptoms may be carefully assessed for comorbid neurological disorders.

Preventive psychiatry: a blueprint for improving the mental health of young people

Preventive approaches have latterly gained traction for improving mental health in young people. In this paper, we first appraise the conceptual foundations of preventive psychiatry, encompassing the public health, Gordon's, US Institute of Medicine, World Health Organization, and good mental health frameworks, and neurodevelopmentally-sensitive clinical staging models. We then review the evidence supporting primary prevention of psychotic, bipolar and common mental disorders and promotion of good mental health as potential transformative strategies to reduce the incidence of these disorders in young people. Within indicated approaches, the clinical high-risk for psychosis paradigm has received the most empirical validation, while clinical high-risk states for bipolar and common mental disorders are increasingly becoming a focus of attention. Selective approaches have mostly targeted familial vulnerability and non-genetic risk exposures. Selective screening and psychological/psychoeducational interventions in vulnerable subgroups may improve anxiety/depressive symptoms, but their efficacy in reducing the incidence of psychotic/bipolar/common mental disorders is unproven. Selective physical exercise may reduce the incidence of anxiety disorders. Universal psychological/psychoeducational interventions may improve anxiety symptoms but not prevent depressive/anxiety disorders, while universal physical exercise may reduce the incidence of anxiety disorders. Universal public health approaches targeting school climate or social determinants (demographic, economic, neighbourhood, environmental, social/cultural) of mental disorders hold the greatest potential for reducing the risk profile of the population as a whole. The approach to promotion of good mental health is currently fragmented. We leverage the knowledge gained from the review to develop a blueprint for future research and practice of preventive psychiatry in young people: integrating universal and targeted frameworks; advancing multivariable, transdiagnostic, multi-endpoint epidemiological knowledge; synergically preventing common and infrequent mental disorders; preventing physical and mental health burden together; implementing stratified/personalized prognosis; establishing evidence-based preventive interventions; developing an ethical framework, improving prevention through education/training; consolidating the cost-effectiveness of preventive psychiatry; and decreasing inequalities. These goals can only be achieved through an urgent individual, societal, and global level response, which promotes a vigorous collaboration across scientific, health care, societal and governmental sectors for implementing preventive psychiatry, as much is at stake for young people with or at risk for emerging mental disorders.

Scoping review on the epidemiology, diagnostics and clinical significance of porcine astroviruses

Porcine astroviruses (PoAstVs) have been reported globally and are divided into at least five distinct lineages (PoAstV1-PoAsV5). The primary objective of this review was to summarize the scientific literature about the frequency of detection, associated clinical presentations and type of samples and diagnostic tools used for the detection of porcine astroviruses. The secondary objective was to summarize the body of knowledge about the causal role in disease of PoAstVs using the Bradford Hill framework. A search was conducted using Centre for Biosciences and Agriculture International (CABI), MEDLINE, American Association of Swine Veterinarians (AASV) Swine Information Library (SIL) abstracts, swine conferences including American College of Veterinary Pathologists (ACVP) and American Association of Veterinary Laboratory Diagnosticians (AAVLD). From 168 studies identified by the search, 29 studies were eligible. Results indicated that 69% (20/29) of the literature on PoAstVs have been published between 2011 and 2018. Of 29 papers, 52% were detection studies (15 of 29) and 48% (14 of 29) were case-control studies. Seventy-two per cent (21 of 29) reported differential diagnosis and 10% (3 of 29) reported histologic lesions, out of which 67% (2 of 3) associated the detection of PoAstV3 with development of polioencephalomyelitis. PCR-based assays were the most common diagnostic tools.

The nosological classification of whiplash-associated disorder: a narrative review

Whiplash-associated disorder (WAD) is the most common complaint and purported cause of chronic disability associated with motor vehicle collisions in North America. However, its construct validity remains controversial. This narrative review of the literature summarises the evidence underlying the most commonly theorised biological and psychosocial mechanisms of WAD pathogenesis. While the face validity of WAD is good, empirical evidence supporting the various constructs suggesting a causal link between a trauma mechanism and the development of symptoms is poor. Because individual expectations of recovery are outcome-predictive, future research is necessary to develop a better understanding of how to enhance expectancies in order to help affected motorists gain a greater sense of control over their health and wellbeing.

Melanoma is associated with an increased risk of bullous pemphigoid: a large population-based longitudinal study

The association between bullous pemphigoid (BP) and melanoma is yet to be investigated. We aimed to assess assess the bidirectional association between BP and melanoma and to delineate the epidemiological features of patients with both diagnoses. A population-based cohort study was performed comparing BP patients (n = 3924) with age-, sex- and ethnicity-matched control subjects (n = 19,280) with regard to incident cases of melanoma. A case-control design was additionally adopted to estimate the risk of BP in individuals with a preexisting diagnosis of melanoma. The prevalence of preexisting melanoma was higher in patients with BP than in control subjects (1.5% vs. 1.0%, respectively; P = 0.004). A history of melanoma confers a 50% increase in the risk of subsequent BP (OR 1.53; 95% CI 1.14-2.06). This risk was higher among males (OR 1.66; 95% CI 1.09-2.54) and individuals older than 80 years (OR 1.63; 95% CI 1.11-2.38), and persisted after adjustment for multiple putative confounders including PD-1/PDL-1 antagonists (adjusted OR 1.53; 95% CI 1.14-2.06). Conversely, the risk of melanoma among patients with BP was slightly elevated, but did not reach the level of statistical significance (adjusted HR 1.13; 95% CI 0.73-1.74). Patients with a dual diagnosis of BP and melanoma were older at the onset of BP and had lower body mass index. A history of melanoma is associated with a 50% increase in the incidence of subsequent BP. Physicians managing patients with both conditions should be aware of this association. Further research is warranted to reveal the underlying mechanism of these findings.

Unusual aetiology of a type 2 myocardial infarction: a case-based review

Organophosphate pesticide (OP) poisoning is quite common and can cause cardiovascular complications and even direct myocardial injury. However, no guideline has included an acute poisoning as a potential cause for a type 2 myocardial infarction (MI) so far. Here we present a case of a 61-year-old woman brought by ambulance to emergency department one hour after accidental ingestion of an unknown quantity of a solution she used against flea infestation. The patient presented with dizziness, myosis, excessive sweating, hypersalivation, sphincteric incontinence, muscle fasciculation, tremor of the extremities, pale skin, alcoholic and pesticide breath odour. Even though we had no guidelines to fall back on, we successfully treated the patient with low-molecular-weight heparin, antiplatelets, statin, diltiazem, antidote therapy, and supportive care. Physicians should be aware that OP poisoning can induce type 2 MI as a complication within a few hours since exposure, and emergency management should always include close cardiac monitoring.

Estimating the Odds of Ulcerative Colitis-Associated Pyoderma Gangrenosum: A Population-Based Case-Control Study

BACKGROUND

Ulcerative colitis (UC) is a well-known underlying comorbidity of pyoderma gangrenosum (PG). However, the risk conferred by UC for the subsequent development of PG is yet to be elucidated. We aimed to estimate the magnitude of the association between UC and the subsequent occurrence of PG, which would enable us to assess the odds of PG developing in individuals with a history of UC.

METHODS

A population-based case-control study was conducted to compare PG patients (n = 302) and age-, sex- and ethnicity-matched control subjects (n = 1,497) regarding the presence of UC. Logistic regression models were utilized for univariate and multivariate analyses.

RESULTS

The prevalence of preexisting UC was greater in patients with PG than in controls (7.3 vs. 0.5%; p < 0.001). A 15-fold increase in the odds of PG in individuals with preexisting UC was observed (OR 14.62, 95% CI 6.45-33.18). The greatest risk of developing PG occurred in the first years following the diagnosis of UC (OR 35.50, 95% CI 4.35-289.60), and decreased thereafter to 10.03 (95% CI 1.83-55.03), 6.69 (95% CI 1.49-30.02), and 10.03 (95% CI 1.83-55.03) at 1-5, 5-10, and 10-15 years after the diagnosis of UC, respectively. This association retained its statistical significance following the adjustment for confounding factors (adjusted OR 10.78, 95% CI 4.55-25.52). Patients with both PG and UC were younger and had a lower prevalence of smoking than the remaining patients with PG.

CONCLUSIONS

UC increases the odds of developing PG by 15-fold, with the highest probability of developing PG occurring within the first year after the diagnosis of UC. Patients with UC may be advised to avoid additional precipitating factors for the development of PG.

Does Obesity Increase the Risk and Severity of Falls in People Aged 60 Years and Older? A Systematic Review and Meta-analysis of Observational Studies

BACKGROUND

Recent investigations suggest that obesity may be associated with an increased risk of falls; however, this theory has yet to be definitively confirmed. This systematic review and meta-analysis examined the strength of the association between obesity and falls, multiple falls, fall-related injuries, and fall-related fractures among older adults.

METHODS

MEDLINE, Embase, CINAHL, PsycINFO, SPORTDiscus, LILACS, and Web of Science databases were searched to identify observational studies that assessed the association between obesity and fall-related outcomes in participants aged 60 years and older. Two independent reviewers performed data extraction and quality assessment. Relative risks and 95% confidence intervals (CI) were pooled using random effect meta-analyses.

RESULTS

Thirty-one studies including a total of 1,758,694 participants were selected from 7,815 references. Pooled estimates showed that obese older adults have an increased risk of falls compared with nonobese counterparts (24 studies; relative risk: 1.16; 95% CI: 1.07-1.26; I2: 90%). Obesity was also associated with an increased risk of multiple falls (four studies; relative risk: 1.18; 95% CI: 1.08-1.29; I2: 0%). There was no evidence, however, of an association between obesity and fall-related injuries (seven studies; relative risk: 1.04; 95% CI: 0.92-1.18; I2: 65%). Fall-related fractures were reported in only one study, which demonstrated a lower risk of hip fracture with obesity (odds ratio: 0.65; 95% CI: 0.63-0.68).

CONCLUSIONS

Obesity increases the risk of falls and multiple falls in people aged 60 years and older; however, there is insufficient evidence of an association with fall-related injuries or fractures. Prevention and treatment of obesity may play a role in preventing falls in older age.

Risk of solid malignancies in bullous pemphigoid: A large-scale population-based cohort study

The association of bullous pemphigoid (BP) with solid malignancies (SM) is a matter of controversy, as previous studies produced inconclusive findings. The aim of this study was to assess the risk of SM among patients with BP and to evaluate whether a history of SM predisposes individuals to develop subsequent BP. A population-based cohort study was performed comparing BP patients (n = 3924) with age-, sex- and race-matched control subjects (n = 19 280) with regard to incident cases of SM. Adjusted hazard ratios (HR) and adjusted odds ratios (OR) were estimated by Cox regression and logistic regression, respectively. The incidence of SM was 13.4 (95% confidence interval [CI], 11.6-15.3) and 14.3 (95% CI, 13.5-15.1) per 1000 person-years among patients with BP and controls, respectively. BP was not associated with an increased risk of SM (adjusted HR, 0.90; 95% CI, 0.77-1.05). Additionally, a history of SM was not related to the risk of subsequent BP (adjusted OR, 1.00; 95% CI, 0.90-1.10). In a stratified analysis, patients with BP had an increased risk of uterine cancer (adjusted HR, 2.56; 95% CI, 1.39-4.72) unlike the 18 remaining analyzed types of SM. Relative to BP patients without SM, those with BP and SM were older, had a male predominance, a higher prevalence of smoking, a higher burden of comorbidities and comparable survival rates. Although patients with BP do not experience an overall increased risk of developing SM, they are more likely to have uterine cancer. Our findings argue against routine extended cancer screening for patients with incident BP, but raise the awareness of uterine cancer among females with BP.

Neutrophil to lymphocyte ratio and cancer prognosis: an umbrella review of systematic reviews and meta-analyses of observational studies

BACKGROUND

Although neutrophils have been linked to the progression of cancer, uncertainty exists around their association with cancer outcomes, depending on the site, outcome and treatments considered. We aimed to evaluate the strength and validity of evidence on the association between either the neutrophil to lymphocyte ratio (NLR) or tumour-associated neutrophils (TAN) and cancer prognosis.

METHODS

We searched MEDLINE, Embase and Cochrane Database of Systematic Reviews from inception to 29 May 2020 for systematic reviews and meta-analyses of observational studies on neutrophil counts (here NLR or TAN) and specific cancer outcomes related to disease progression or survival. The available evidence was graded as strong, highly suggestive, suggestive, weak or uncertain through the application of pre-set GRADE criteria.

RESULTS

A total of 204 meta-analyses from 86 studies investigating the association between either NLR or TAN and cancer outcomes met the criteria for inclusion. All but one meta-analyses found a hazard ratio (HR) which increased risk (HR > 1). We did not find sufficient meta-analyses to evaluate TAN and cancer outcomes (N = 9). When assessed for magnitude of effect, significance and bias related to heterogeneity and small study effects, 18 (9%) associations between NLR and outcomes in composite cancer endpoints (combined analysis), cancers treated with immunotherapy and some site specific cancers (urinary, nasopharyngeal, gastric, breast, endometrial, soft tissue sarcoma and hepatocellular cancers) were supported by strong evidence.

CONCLUSION

In total, 60 (29%) meta-analyses presented strong or highly suggestive evidence. Although the NLR and TAN hold clinical promise in their association with poor cancer prognosis, further research is required to provide robust evidence, assess causality and test clinical utility.

TRIAL REGISTRATION

PROSPERO CRD42017069131 .

INFERENCE: An Evidence-Based Approach for Medicolegal Causal Analyses

A fundamental purpose of forensic medical, or medicolegal, analysis is to provide legal factfinders with an opinion regarding the causal relationship between an alleged unlawful or negligent action and a medically observed adverse outcome, which is needed to establish legal liability. At present, there are no universally established standards for medicolegal causal analysis, although several different approaches to causation exist, with varying strengths and weaknesses and degrees of practical utility. These approaches can be categorized as intuitive or probabilistic, which are distributed along a spectrum of increasing case complexity. This paper proposes a systematic approach to evidence-based assessment of causation in forensic medicine, called the INtegration of Forensic Epidemiology and the Rigorous EvaluatioN of Causation Elements (INFERENCE) approach. The INFERENCE approach is an evolution of existing causal analysis methods and consists of a stepwise method of increasing complexity. We aimed to develop a probabilistic causal analysis approach that (1) fits the needs of legal factfinders who require an estimate of the probability of causation, and (2) is still sufficiently straightforward to be applied in real-world forensic medical practice. As the INFERENCE approach is most relevant in complex cases, we also propose a process for selecting the most appropriate causal analysis method for any given case. The goal of this approach is to improve the reproducibility and transparency of causal analyses, which will promote evidence-based practice and quality assurance in forensic medicine, resulting in expert opinions that are reliable and objective in legal proceedings.

Traditional Risk Factors are Causally Related to Carotid Intima-Media Thickness Progression: Inferences from Observational Cohort Studies and Interventional Trials

In the present review, associations between traditional vascular risk factors (VRFs) and carotid intimamedial thickness progression (C-IMTp) as well as the effects of therapies for VRFs control on C-IMTp were appraised to infer causality between each VRF and C-IMTp. Cohort studies indicate that smoking, binge drinking, fatness, diabetes, hypertension and hypercholesterolemia are associated with accelerated C-IMTp. An exception is physical activity, with mixed data. Interventions for the control of obesity, diabetes, hypertension and hypercholesterolemia decelerate C-IMTp. Conversely, scarce information is available regarding the effect of smoking cessation, stop of excessive alcohol intake and management of the metabolic syndrome. Altogether, these data support a causative role of several traditional VRFs on C-IMTp. Shortcomings in study design and/or ultrasonographic protocols may account for most negative studies, which underlines the importance of careful consideration of methodological aspects in investigations using C-IMTp as the outcome.

Rubella virus-associated chronic inflammation in primary immunodeficiency diseases

PURPOSE OF THE REVIEW

The aim of this article is to summarize recent data on rubella virus (RuV) vaccine in chronic inflammation focusing on granulomas in individuals with primary immunodeficiencies (PIDs).

RECENT FINDINGS

The live attenuated RuV vaccine has been recently associated with cutaneous and visceral granulomas in children with various PIDs. RuV vaccine strain can persist for decades subclinically in currently unknown body site(s) before emerging in granulomas. Histologically, RuV is predominately localized in M2 macrophages in the granuloma centers. Multiple mutations accumulate during persistence resulting in emergence of immunodeficiency-related vaccine-derived rubella viruses (iVDRVs) with altered immunological, replication, and persistence properties. Viral RNA was detected in granuloma biopsies and nasopharyngeal secretions and infectious virus were isolated from the granuloma lesions. The risk of iVDRV transmissibility to contacts needs to be evaluated. Several broad-spectrum antiviral drugs have been tested recently but did not provide significant clinical improvement. Hematopoietic stem cell transplantation remains the only reliable option for curing chronic RuV-associated granulomas in PIDs.

SUMMARY

Persistence of vaccine-derived RuVs appears to be a crucial factor in a significant proportion of granulomatous disease in PIDs. RuV testing of granulomas in PID individuals might help with case management.