Proportion and number of cancer cases and deaths attributable to potentially modifiable risk factors in the United States, 2019.

In 2018, the authors reported estimates of the number and proportion of cancers attributable to potentially modifiable risk factors in 2014 in the United States. These data are useful for advocating for and informing cancer prevention and control. Herein, based on up-to-date relative risk and cancer occurrence data, the authors estimated the proportion and number of invasive cancer cases (excluding nonmelanoma skin cancers) and deaths, overall and for 30 cancer types among adults who were aged 30 years and older in 2019 in the United States, that were attributable to potentially modifiable risk factors. These included cigarette smoking; second-hand smoke; excess body weight; alcohol consumption; consumption of red and processed meat; low consumption of fruits and vegetables, dietary fiber, and dietary calcium; physical inactivity; ultraviolet radiation; and seven carcinogenic infections. Numbers of cancer cases and deaths were obtained from data sources with complete national coverage, risk factor prevalence estimates from nationally representative surveys, and associated relative risks of cancer from published large-scale pooled or meta-analyses. In 2019, an estimated 40.0% (713,340 of 1,781,649) of all incident cancers (excluding nonmelanoma skin cancers) and 44.0% (262,120 of 595,737) of all cancer deaths in adults aged 30 years and older in the United States were attributable to the evaluated risk factors. Cigarette smoking was the leading risk factor contributing to cancer cases and deaths overall (19.3% and 28.5%, respectively), followed by excess body weight (7.6% and 7.3%, respectively), and alcohol consumption (5.4% and 4.1%, respectively). For 19 of 30 evaluated cancer types, more than one half of the cancer cases and deaths were attributable to the potentially modifiable risk factors considered in this study. Lung cancer had the highest number of cancer cases (201,660) and deaths (122,740) attributable to evaluated risk factors, followed by female breast cancer (83,840 cases), skin melanoma (82,710), and colorectal cancer (78,440) for attributable cases and by colorectal (25,800 deaths), liver (14,720), and esophageal (13,600) cancer for attributable deaths. Large numbers of cancer cases and deaths in the United States are attributable to potentially modifiable risk factors, underscoring the potential to substantially reduce the cancer burden through broad and equitable implementation of preventive initiatives.

Global patterns in excess body weight and the associated cancer burden.

The prevalence of excess body weight and the associated cancer burden have been rising over the past several decades globally. Between 1975 and 2016, the prevalence of excess body weight in adults-defined as a body mass index (BMI) ≥ 25 kg/m2 -increased from nearly 21% in men and 24% in women to approximately 40% in both sexes. Notably, the prevalence of obesity (BMI ≥ 30 kg/m2 ) quadrupled in men, from 3% to 12%, and more than doubled in women, from 7% to 16%. This change, combined with population growth, resulted in a more than 6-fold increase in the number of obese adults, from 100 to 671 million. The largest absolute increase in obesity occurred among men and boys in high-income Western countries and among women and girls in Central Asia, the Middle East, and North Africa. The simultaneous rise in excess body weight in almost all countries is thought to be driven largely by changes in the global food system, which promotes energy-dense, nutrient-poor foods, alongside reduced opportunities for physical activity. In 2012, excess body weight accounted for approximately 3.9% of all cancers (544,300 cases) with proportion varying from less than 1% in low-income countries to 7% or 8% in some high-income Western countries and in Middle Eastern and Northern African countries. The attributable burden by sex was higher for women (368,500 cases) than for men (175,800 cases). Given the pandemic proportion of excess body weight in high-income countries and the increasing prevalence in low- and middle-income countries, the global cancer burden attributable to this condition is likely to increase in the future. There is emerging consensus on opportunities for obesity control through the multisectoral coordinated implementation of core policy actions to promote an environment conducive to a healthy diet and active living. The rapid increase in both the prevalence of excess body weight and the associated cancer burden highlights the need for a rejuvenated focus on identifying, implementing, and evaluating interventions to prevent and control excess body weight.

The Global Incident Gastrointestinal Cancers Attributable to Suboptimal Diets From 1990 to 2018.

BACKGROUND & AIMS: The contribution of suboptimal diets to gastrointestinal (GI) cancer incidence globally remains unquantified, and we aimed to evaluate it. METHODS: Comprehensive meta-analyses and rigorous evidence-grading assessment identified the associations between suboptimal diets and 6 GI cancers and their subtypes. A comparative risk assessment model was used to estimate the proportional attributable burden and attributable rate of GI cancers to suboptimal diets by using the corroborative association estimates. In addition, correlation assessments with the Sociodemographic Index were carried out. RESULTS: In 2018, 21.5% (95% uncertainty interval, 19.1%-24.5%) of incident GI cancer cases globally were attributable to suboptimal diets, maintaining a relatively stable proportion since 1990 (22.4%; 19.7%-25.6%), whereas the absolute diet-attributable cases doubled from 580,862 (510,658-664,076) in 1990 to 1,039,877 (923,482-1,187,244) in 2018. Excessive processed meat consumption (5.9%; 4.2%-7.9%), insufficient fruit intake (4.8%; 3.8%-5.9%), and insufficient whole grain intake (3.6%; 2.8%-5.1%) were the most significant dietary risk factors in 2018, a shift from 1990 when the third major concern was insufficient nonstarchy vegetable intake. In addition, Central and Eastern Europe and Central Asia experienced the highest attributable burden across regions in both 1990 (31.6%; 27.0%-37.4%) and 2018 (31.6%; 27.3%-36.5%), and a positive correlation (P < .001) between the Sociodemographic Index and the attributable GI cancer incidence was observed. CONCLUSIONS: Although the proportional attributable GI incidence remains relatively stable, the doubling of absolute cases from 1990 to 2018, along with the discrepancies among urbanicity and countries/regions, informs dietary priorities and more targeted preventive measures.

Proportion and number of cancer cases and deaths attributable to potentially modifiable risk factors in the United States.

Contemporary information on the fraction of cancers that potentially could be prevented is useful for priority setting in cancer prevention and control. Herein, the authors estimate the proportion and number of invasive cancer cases and deaths, overall (excluding nonmelanoma skin cancers) and for 26 cancer types, in adults aged 30 years and older in the United States in 2014, that were attributable to major, potentially modifiable exposures (cigarette smoking; secondhand smoke; excess body weight; alcohol intake; consumption of red and processed meat; low consumption of fruits/vegetables, dietary fiber, and dietary calcium; physical inactivity; ultraviolet radiation; and 6 cancer-associated infections). The numbers of cancer cases were obtained from the Centers for Disease Control and Prevention (CDC) and the National Cancer Institute; the numbers of deaths were obtained from the CDC; risk factor prevalence estimates were obtained from nationally representative surveys; and associated relative risks of cancer were obtained from published, large-scale pooled analyses or meta-analyses. In the United States in 2014, an estimated 42.0% of all incident cancers (659,640 of 1570,975 cancers, excluding nonmelanoma skin cancers) and 45.1% of cancer deaths (265,150 of 587,521 deaths) were attributable to evaluated risk factors. Cigarette smoking accounted for the highest proportion of cancer cases (19.0%; 298,970 cases) and deaths (28.8%; 169,180 deaths), followed by excess body weight (7.8% and 6.5%, respectively) and alcohol intake (5.6% and 4.0%, respectively). Lung cancer had the highest number of cancers (184,970 cases) and deaths (132,960 deaths) attributable to evaluated risk factors, followed by colorectal cancer (76,910 cases and 28,290 deaths). These results, however, may underestimate the overall proportion of cancers attributable to modifiable factors, because the impact of all established risk factors could not be quantified, and many likely modifiable risk factors are not yet firmly established as causal. Nevertheless, these findings underscore the vast potential for reducing cancer morbidity and mortality through broad and equitable implementation of known preventive measures. CA Cancer J Clin 2018;68:31-54. © 2017 American Cancer Society.

Cancer cases attributable to modifiable lifestyle risk factors in Switzerland between 2015 and 2019.

Several modifiable lifestyle risk factors have been linked to higher cancer risk in the literature. Determining the proportion and number of cancer cases attributable to these risk factors is pivotal in informing effective cancer prevention and control plans that have the greatest effect on reducing cancer incidence. We aimed to estimate the proportion and number of incident cancer cases that were attributable to modifiable lifestyle risk factors (ie, tobacco smoking, high alcohol consumption, excess body weight, physical inactivity and unhealthy diet) in Switzerland between 2015 and 2019. The exposure prevalence of selected risk factors was estimated based on the representative national nutrition survey menuCH, the associated relative risks were obtained from systematic literature reviews and the numbers of incident cancer cases were provided by the National Institute for Cancer Epidemiology and Registration. The fractions and numbers of attributable cases were calculated overall, by sex and by the three major language regions of Switzerland. The investigated modifiable risk factors combined were linked to 25.2% of potentially preventable incident cancer cases in Switzerland between 2015 and 2019. The proportion and numbers were slightly larger in males (28.4%, 6945 cases per year) than in females (21.9%, 4493 cases per year), and variations were observed between language regions. Tobacco smoking, excess body weight and high alcohol consumption were the leading contributors to lifestyle-attributable cancer cases. The observed differences in the leading risk factors both within Switzerland and compared to other countries underline the need for regionally and nationally tailored cancer prevention and education strategies.

Time trends of 16 modifiable risk factors on the burden of major cancers among the Chinese population.

The cancer burden in China is increasing. We aimed to assess the time trends in the prevalence of 16 modifiable risk factors involved in lifestyle, diet, infection, and air pollution between 1997 and 2025 based on the China Health and Nutrition Survey, the Global Burden of Disease website, and publically available studies. The population attributable fraction (PAF) and its 95% uncertainty interval (UI) from 2007 to 2035 were calculated to quantify the attributable cancer burden in major 12 anatomic sites using the comparative risk assessment method, considering a 10-year lag effect. As a result, 1,559,476 cancer cases (PAF = 54.1%, 95% UI: 36.8%-65.8%) from the 12 anatomic sites were attributable to these modifiable risk factors in 2007, with lung, liver, and gastric cancer raging the top three. It was predicted that by 2035, the attributable cancer cases would reach 1,680,098 (PAF = 44.2%, 95% UI: 29.1%-55.5%), with the top three of lung, liver, and colorectal cancer. Smoking, physical inactivity, insufficient fruit consumption, HBV infection, and Helicobacter pylori infection were the most attributable risk factors in 2007, contributing to 480,352, 233,684, 215,009, 214,455, and 187,305 associated cancer cases, respectively. In 2035, the leading factors for cancer would be smoking, physical inactivity, insufficient fruit intake, HPV infection, and HBV infection, resulting in 427,445, 424,327, 185,144, 156,535, and 154,368 cancer cases, respectively. Intervention strategies should be swiftly established and dynamically altered in response to risk factors like smoking, physical inactivity, poor fruit intake, and infectious factors that may cause a high cancer burden in the Chinese population.

A historical cohort study with 27,754 individuals on the association between meat consumption and gastrointestinal tract and colorectal cancer incidence.

In order to explore the association between meat consumption and gastrointestinal/colorectal cancer (CRC) risk and to estimate the Israeli population attributable fraction (PAF), we conducted a collaborative historical cohort study using the individual participant data of seven nutritional studies from the past 6 decades. We included healthy adult men and women who underwent a nutritional interview. Dietary assessment data, using food-frequency or 24-h recall questionnaires, were harmonized. The study file was linked to the National Cancer and death registries. Among 27,754 participants, 1216 (4.4%) were diagnosed with gastrointestinal cancers and 839 (3.0%) with CRC by the end of 2016. Using meta-analysis methods applied to Cox proportional hazard models (adjusted for daily energy intake, sex, age, ethnic origin, education and smoking),100 g/day increments in beef, red meat and poultry consumption, and 50 g/day increment in processed meat consumption were associated with hazard ratios (HRs) and 95% confidence intervals of 1.46 (1.06-2.02), 1.15 (0.87-1.52), 1.06 (0.89-1.26), and 0.93 (0.76-1.12), respectively, for CRC. Similar results were obtained for gastrointestinal cancer, although red meat consumption reached statistical significance (HR = 1.27; 95%CI: 1.02-1.58). The PAFs associated with a reduction to a maximum of 50 g/day in the consumption of red meat were 2.7% (95%CI: -1.9 to 12.0) and 5.2% (0.3-13.9) for CRC and gastrointestinal cancers, respectively. Reduction of beef consumption to a maximum of 50 g/day will result in a CRC PAF reduction of 7.5% (0.7%-24.3%). While beef consumption was associated with gastrointestinal/CRC excess risk, poultry consumption was not. A substantial part of processed meat consumption in Israel is processed poultry, perhaps explaining the lack of association with CRC.

Population Attributable Fraction of Total Stroke Associated with Modifiable Risk Factors in the United States.

Stroke is a leading cause of death in the United States across all race/ethnicity and sex groups, though disparities exist. We investigated the potential for primary prevention of total first stroke for Americans aged 20 and older, stratified by sex and race/ethnicity. Specifically, we calculated population attributable fractions (PAF) of first stroke for 7 potentially modifiable risk factors: smoking, physical inactivity, poor diet, obesity, hypertension, diabetes, and atrial fibrillation. PAFs are a function of (1) the relative risk of first stroke for people with the exposure and (2) the prevalence of the risk factor in the population. Relative risks came from recent meta-analyses and sex-race/ethnicity-specific prevalence estimates came from the 2015-2018 NHANES or Multi-Ethnic Study of Atherosclerosis (for atrial fibrillation only). Approximately 1/3 (35.7% [CI: 21.6%-49.0%]) for women, 32.7% [CI: 19.2%-45.1%] for men) of strokes were attributable to the 7 risk factors we considered. A 20% proportional reduction in stroke risk factors would result in approximately 37,000 fewer strokes annually in the United States. The estimated PAF was highest for non-Hispanic Black women (39.3% [CI: 24.8%-52.3%]) and lowest for non-Hispanic Asian men (25.5% [CI: 14.6%-36.2%]). For most groups, obesity and hypertension were the largest contributors to stroke rates.

Population Attributable Fraction of Nonvaccination of COVID-19 Due to Vaccine Hesitancy, United States, 2021.

Understanding the extent of coronavirus disease 2019 (COVID-19) nonvaccination attributable to vaccine hesitancy versus other barriers can help prioritize approaches for increasing vaccination uptake. Using data from the Centers for Disease Control and Prevention's Research and Development Survey, a nationally representative survey fielded from May 1 to June 30, 2021 (n = 5,458), we examined the adjusted population attribution fraction (PAF) of COVID-19 vaccine hesitancy attributed to nonvaccination according to sociodemographic characteristics and health-related variables. Overall, the adjusted PAF of nonvaccination attributed to vaccine hesitancy was 76.1%. The PAF was highest among adults who were ≥50 years of age (87.9%), were non-Hispanic White (83.7%), had a bachelor's degree or higher (82.7%), had an annual household income of at least $75,000 (85.5%), were insured (82.4%), and had a usual place for health care (80.7%). The PAF was lower for those who were current smokers (65.3%) compared with never smokers (77.9%), those who had anxiety or depression (65.2%) compared with those who did not (80.1%), and those who had a disability (64.5%) compared with those who did not (79.2%). Disparities in PAF suggest areas for prioritization of efforts for intervention and development of messaging campaigns that address all barriers to uptake, including hesitancy and access, to advance health equity and protect individuals from COVID-19.

Estimating smoking-attributable lung cancer mortality in Chinese adults from 2000 to 2020: a comparison of three methods.

BACKGROUND: Smoking is a significant public health concern in China and a leading cause of lung cancer deaths among adults. This study aims to employ three methods to estimate smoking-attributable lung cancer mortality among Chinese adults from 2000 to 2020. METHODS: Population attributable fractions (PAFs) of lung cancer deaths caused by smoking were estimated using lagged smoking prevalence, Peto-Lopez, and dose-response relationship methods, separately. Smoking exposure was obtained from national tobacco surveys in China, and relative risks (RR) were derived from a meta-analysis of state-of-the-art studies among the Chinese population. Finally, we estimated the sex- and age-stratified smoking-attributable lung cancer deaths in Chinese population in 2000, 2005, 2010, 2015, and 2020. RESULTS: The PAFs estimated using 5- and 10-year lagged smoking prevalence method (45-47%) and Peto-Lopez method (46-47%) were similar, while PAFs calculated using the dose-response method were highest (47-58%). The PAFs were consistently higher in males than in females. Age-specific PAFs estimated by lagged smoking prevalence method (54-60%) and the Peto-Lopez method (57-61%) in males were similar and relatively stable, with slight decreases in older populations, while the dose-response relationship-based PAFs increased with age and fluctuated by year. By using the above methods, smoking-attributable lung cancer deaths were estimated to be 134,100, 134,600, 136,600, and 155,300 in 2000 increasing to 310,300, 301,100, 306,000, and 314,700 in 2020, respectively. CONCLUSION: The estimation from dose-response methods could better reflect the smoking effect, however, high-quality data and accurate estimation of parameters are necessary.

Proportion of cancer cases and deaths attributable to potentially modifiable risk factors in Peru.

BACKGROUND: Limited evidence exists on the population attributable fraction (PAF) of cancer cases and deaths in Latin America. In Peru several studies have been published regarding the PAF of various risk factors and their associated diseases. The objective of this study was to estimate the fraction of cancer cases and deaths attributable to potentially modifiable risk factors in Peru in 2018, before the COVID-19 pandemic in the population of 15 years old and older. METHODS: An ecological study was conducted using the prevalence of exposure of the Peruvian population to modifiable risk factors for cancer, the relative risk associated with each factor, and the number of cancer cases and deaths in 2018 as inputs. We used the Parkin formula with a Montecarlo statistical simulation model to calculate the PAF and confidence intervals. The number of new cancer cases and deaths attributed to each risk factor was determined by multiplying the number of cases and deaths in each gender by the PAF of each risk factor. FINDINGS: In Peru, 38.5% of new cases (34.5% in men and 42% in women) and 43.4% of cancer-related deaths (43.4% in men and 43.4% in women) were attributable to modifiable risk factors. The number of cancers attributable was 25,308 (10,439 in men and 14,869 in women) and the number of deaths attributable to cancer was 14,839 (6,953 in men and 7,886 in women). The predominant modifiable risk factors contributing to the highest number of cases and deaths were HPV infection (4,563 cases, 2,409 deaths), current tobacco use (3,348 cases, 2,180 deaths), and helicobacter pylori infection (2,677 cases, 1,873 deaths). Among the risk factors, oncogenic infections constituted the group with the highest PAF (16.6% for cases, 19.2% for deaths) followed by other unhealthy lifestyle factors (14.2% for cases, 16.7% for deaths), tobacco (7.2% for cases, 7.2% for deaths) and ultraviolet radiation (0.5% for cases, 0.3% for deaths). CONCLUSIONS: Prior to the COVID-19 pandemic, 38.5% of cancer cases and 43.4% of cancer-related deaths in Peru were linked to modifiable risk factors in the population of 15 years old and older. Most preventable cancer cases and deaths were related to oncogenic infections, primarily caused by HPV and helicobacter pylori, followed by tobacco and obesity.

Risk factors for incident cardiovascular events and their population attributable fractions in rural India: The Rishi Valley Prospective Cohort Study.

OBJECTIVE: We prospectively determined incident cardiovascular events and their association with risk factors in rural India. METHODS: We followed up with 7935 adults from the Rishi Valley Prospective Cohort Study to identify incident cardiovascular events. Using Cox proportional hazards regression, we estimated hazard ratios (HRs) with 95% confidence intervals (95% CI) for associations between potential risk factors and cardiovascular events. Population attributable fractions (PAFs) for risk factors were estimated using R ('averisk' package). RESULTS: Of the 4809 participants without prior cardiovascular disease, 57.7% were women and baseline mean age was 45.3 years. At follow-up (median of 4.9 years, 23,180 person-years [PYs]), 202 participants developed cardiovascular events, equating to an incidence of 8.7 cardiovascular events/1000 PYs. Incidence was greater in those with hypertension (hazard ratio [HR] [95% CI] 1.73 [1.21-2.49], adjusted PAF 18%), diabetes (1.96 [1.15-3.36], 4%) or central obesity (1.77 [1.23, 2.54], 9%) which together accounted for 31% of the PAF. Non-traditional risk factors such as night sleeping hours and number of children accounted for 16% of the PAF. CONCLUSIONS: Both traditional and non-traditional cardiovascular risk factors are important contributors to incident cardiovascular events in rural India. Interventions targeted to these factors could assist in reducing the incidence of cardiovascular events.

Sex and Socioeconomic Disparities in Dementia Risk: A Population-Attributable Fraction Analysis in Argentina.

INTRODUCTION: Twelve modifiable risk factors (RFs) account for 40% of dementia cases worldwide. However, limited data exist on such factors in middle- and low-income countries. We aimed to estimate the population-attributable fractions (PAFs) for the 12 RFs in Argentina, assessing changes over a decade and exploring socioeconomic and sex influences. METHODS: We conducted cross-sectional analyses of the 12 RFs from Argentinian surveys conducted in 2009, 2015, and 2018, including 96,321 people. We calculated PAFs and stratified estimates based on sex and income. RESULTS: We estimated an overall PAF of 59.6% (95% CI = 58.9-60.3%). The largest PAFs were hypertension = 9.3% (8.7-9.9%), physical inactivity = 7.4% (6.8-8.2%), and obesity = 7.4% (6.8-7.9%). Men were more impacted by excessive alcohol, while women by isolation and smoking. Lower income linked to higher PAFs in education, hypertension, and obesity. DISCUSSION: Argentina has a higher PAF for dementia than the world population, with distinct RF distribution. PAF varied by sex and economic status, advocating tailored prevention strategies.

Global and regional estimates of hip fracture burden associated with type 1 diabetes from 1990 to 2021.

AIM: To assess the global and regional burden of hip fractures associated with type 1 diabetes (T1D) from 1990 to 2021. MATERIALS AND METHODS: The population attributable fraction was calculated by combining the published risk ratio with T1D prevalence (age ≥ 20 years) from the Global Burden of Disease study to estimate the T1D-associated hip-fracture burden. Trends were assessed using the age-standardized incidence rate (ASIR) and estimated annual percentage change (EAPC). RESULTS: The global incidence of T1D-related hip fractures was 290 180 in 2021 with an ASIR of 3.96 (95% confidence interval: 1.92-5.87) per 100 000 population and a male-to-female ratio of 0.54. At the super-regional level, the highest incidence (204 610) and ASIR (13.09 per 100 000 population; 6.40-25.53) were observed in high-income regions, in particular in Australasia and Western Europe. Notably, Australasia exhibited the highest EAPC, 2.90% in T1D-associated ASIR, followed by East Asia (2.73%). The incidence among those aged 45-64 years grew significantly in 14 regions over the past decade. Nationally, the ASIR increased in 166 countries from 1990 to 2021. CONCLUSIONS: High-income regions experienced the greatest burden of T1D-associated hip fracture, while Australasia and East Asia witnessed the largest increase over the last 32 years. Prioritizing the promotion of T1D treatment and hip-fracture screening for middle-aged females living with T1D is crucial in these regions.

Dealing with time-dependent exposures and confounding when defining and estimating attributable fractions-Revisiting estimands and estimators.

The population-attributable fraction (PAF) is commonly interpreted as the proportion of events that can be ascribed to a certain exposure in a certain population. Its estimation is sensitive to common forms of time-dependent bias in the face of a time-dependent exposure. Predominant estimation approaches based on multistate modeling fail to fully eliminate such bias and, as a result, do not permit a causal interpretation, even in the absence of confounding. While recently proposed multistate modeling approaches can successfully eliminate residual time-dependent bias, and moreover succeed to adjust for time-dependent confounding by means of inverse probability of censoring weighting, inadequate application, and misinterpretation prevails in the medical literature. In this paper, we therefore revisit recent work on previously proposed PAF estimands and estimators in settings with time-dependent exposures and competing events and extend this work in several ways. First, we critically revisit the interpretation and applied terminology of these estimands. Second, we further formalize the assumptions under which a causally interpretable PAF estimand can be identified and provide analogous weighting-based representations of the identifying functionals of other proposed estimands. This representation aims to enhance the applied statistician's understanding of different sources of bias that may arise when the aim is to obtain a valid estimate of a causally interpretable PAF. To illustrate and compare these representations, we present a real-life application to observational data from the Ghent University Hospital ICUs to estimate the fraction of ICU deaths attributable to hospital-acquired infections.

The relationship between the systemic immune inflammation index and the nonalcoholic fatty liver disease in American adolescents.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a growing health crisis in the general population of the United States (U.S.), but the relationship between systemic immune-inflammation (SII) index and NAFLD is not known. METHODS: We collected data from the National Health and Nutrition Examination Survey 2017-2018. Next, propensity score matching (PSM), collinearity analysis, restricted cubic spline (RCS) plot, logistic regression, quantile regression analysis, subgroup analysis, mediation analysis, and population attributable fraction were used to explore the association of the SII with risk of NAFLD. RESULTS: A total of 665 participants including the 532 Non-NAFLD and 133 NAFLD were enrolled for further analysis after PSM analysis. The RCS results indicated that there was a linear relationship between the SII and controlled attenuation parameter (p for nonlinear = 0.468), the relationship also existed after adjustment for covariates (p for nonlinear = 0.769). The logistic regression results indicated that a high SII level was an independent risk factor for NAFLD (OR = 3.505, 95% CI: 1.092-11.249, P < 0.05). The quantile regression indicated that at higher quantiles (0.90, and 0.95) the SII was significantly associated with NAFLD (p < 0.05). Mediation analysis indicated that alanine aminotransferase (ALT), triglycerides, and blood urea nitrogen (BUN) were partially contribute to the relationship between SII and NAFLD. The population attributable fractions indicated that 23.19% (95% CI: 8.22%, 38.17%) of NAFLD cases could be attributed to SII corresponding to 133 NAFLD cases. CONCLUSION: There was a positive linear relationship between the SII and the risk of NAFLD. The ALT, triglycerides, and BUN had a partial mediating effect on the relationship between the SII and NAFLD.

Maternal Exposure to Extreme Cold Events and Risk of Congenital Heart Defects: A Large Multicenter Study in China.

Over the past decade, extreme temperature events have become more frequent and longer in duration. Previous studies on the association between extreme cold events (ECEs) and congenital heart defects (CHDs) are few and inconsistent. We conducted a national multicenter study in 1313 hospitals in 26 provinces in China and collected a total of 14 808 high CHD-risk participants from 2013 to 2021. We evaluated the ECEs experienced by each pregnant women during the embryonic period (3-8 weeks). The results indicated that ECEs experienced by pregnant women during the embryonic period were associated with the development of fetal CHD and were more strongly associated with some specific fetal CHD subtypes, such as pulmonary stenosis, pulmonary atresia, and tetralogy of Fallot. Of the CHD burden, 2.21% (95% CI: 1.43, 2.99%)-2.40% (95% CI: 1.26, 3.55%) of fetal CHD cases were attributable to ECEs during the embryonic period. Our findings emphasize the need to pay more attention to pregnant women whose embryonic period falls during the cold season to reduce cold spell detriments to newborns.

Reevaluating the fraction of cancer attributable to excess weight: overcoming the hidden impact of prediagnostic weight loss.

OBJECTIVE: To evaluate the magnitude of the potential underestimation of the proportion of cancer cases attributable to excess weight, known as population attributable fraction (PAF), due to potential bias from prediagnostic weight loss already present at baseline of cohort studies and to overcome it as much as possible. METHODS: Data from the UK Biobank cohort participants aged 40-69 without prior cancer diagnosis were analyzed. We assessed the magnitude of associations of excess weight with the incidence of obesity-related cancers combined, and separately for gastrointestinal (GI) and other cancers. Using multivariable Cox proportional hazards models, hazard ratios (HR) and their 95% confidence intervals (CI), and PAFs for excess weight at baseline were estimated for various periods of time after weight measurements. FINDINGS: Of 458,660 participants, 20,218 individuals developed obesity-related cancers during a median 11.0-year follow-up, comprising 8,460 GI, and 11,765 non-GI cancers. PAFs were much higher for cancers occurring more than four years after recruitment than for cancers occurring within the initial four years: 17.7% versus 7.2%, 21.4% versus 11.7% for GI, non-GI and all obesity-related cancers combined, respectively. With respect to total cancer (including cancers with no established relationship with excess weight), PAFs were estimated as 5.1% and 8.8% for the 0-4 and 4-14-year periods of follow-up. CONCLUSION: The proportion of cancers attributable to excess weight is likely substantially larger than previously estimated based on cohort studies with short follow-up time or no or only limited exclusion of the early years of follow-up from the analyses.

Bias assessment and correction for Levin's population attributable fraction in the presence of confounding.

In 1953, Morton Levin introduced a simple approach to estimating population attributable fractions (PAF) depending only on risk factor prevalence and relative risk. This formula and its extensions are still in widespread use today, particularly to estimate PAF in populations where individual data is unavailable. Unfortunately, Levin's approach is known to be asymptotically biased for the PAF when the risk factor-disease relationship is confounded even if relative risks that are correctly adjusted for confounding are used in the estimator. Here we describe a simple re-expression of Miettinen's estimand that depends on the causal relative risk, the unadjusted relative risk and the population risk factor prevalence. While this re-expression is not new, it has been underappreciated in the literature, and the associated estimator may be useful in estimating PAF in populations when individual data is unavailable provided estimated adjusted and unadjusted relative risks can be transported to the population of interest. Using the re-expressed estimand, we develop novel analytic formulae for the relative and absolute asymptotic bias in Levin's formula, solidifying earlier work by Darrow and Steenland that used simulations to investigate this bias. We extend all results to settings with non-binary valued risk factors and continuous exposures and discuss the utility of these results in estimating PAF in practice.

Estimating and displaying population attributable fractions using the R package: graphPAF.

Here we introduce graphPAF, a comprehensive R package designed for estimation, inference and display of population attributable fractions (PAF) and impact fractions. In addition to allowing inference for standard population attributable fractions and impact fractions, graphPAF facilitates display of attributable fractions over multiple risk factors using fan-plots and nomograms, calculations of attributable fractions for continuous exposures, inference for attributable fractions appropriate for specific risk factor → mediator → outcome pathways (pathway-specific attributable fractions) and Bayesian network-based calculations and inference for joint, sequential and average population attributable fractions in multi-risk factor scenarios. This article can be used as both a guide to the theory of attributable fraction estimation and a tutorial regarding how to use graphPAF in practical examples.