Publications by authors named "Richard F MacLehose"

Background: Empirically evaluating the potential impact of recall bias on observed associations of prenatal medication exposure is crucial.

Objective: We sought to assess the effects of exposure misclassification on previous studies of the use of nonsteroidal anti-inflammatory drugs (NSAIDs) in early pregnancy and increased risk of amniotic band syndrome (ABS).

Methods: Using data from the National Birth Defects Prevention Study (NBDPS) on births from 1997 to 2011, we included 189 mothers of infants with ABS and 11,829 mothers of infants without congenital anomalies.

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To account for misclassification of dichotomous variables using probabilistic bias analysis, beta distributions are often assigned to bias parameters (e.g., PPV and NPV) based on data from an internal validation substudy.

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Background: A 2013 meta-analysis observed a protective association between overweight BMI (versus normal BMI) and all-cause mortality that was particularly strong in people aged ≥65. Estimates informing this meta-analysis were highly heterogeneous, and critics raised insufficient or inappropriate confounder adjustment in many studies as an explanation for the protective summary association. Using this topic as an example, we demonstrate a novel approach for external adjustment of individual studies for a uniform and sufficient confounder set before meta-analysis.

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  • The study assesses how systematic biases from loss of heterozygosity (LOH) and incomplete phenotyping affect the links between CYP2D6 genetic variants and breast cancer recurrence in women treated with tamoxifen.
  • A systematic literature review and a quantitative bias analysis were conducted, leading to a meta-analysis which adjusted for these biases and found that individuals with poor CYP2D6 metabolism had a higher risk of breast cancer recurrence or mortality.
  • The findings indicate that lower CYP2D6 activity correlates with increased breast cancer risks, highlighting the importance of addressing biases in research to better understand genetic impacts on health outcomes.
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  • Severe asthma can be exacerbated by specific environmental conditions, particularly during thunderstorms with high pollen, known as 'thunderstorm asthma.'
  • A study in Minneapolis-St. Paul analyzed emergency department visits for asthma during these events, revealing that while overall risk increased by 6%, children under 18 showed no heightened risk compared to adults ages 18-44 and those 45 and older, who had a higher relative risk of asthma-related visits.
  • The findings emphasize the need for more awareness and tailored clinical treatments based on varying susceptibility to thunderstorm asthma across different age and sex groups, highlighting it as an important environmental health issue.
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Mismeasurement of a dichotomous outcome yields an unbiased risk ratio estimate when there are no false positive cases (perfect specificity) and when sensitivity is non-differential with respect to exposure status. In studies where these conditions are expected, quantitative bias analysis may be considered unnecessary. We conducted a simulation study to explore the robustness of this special case to small departures from perfect specificity and stochastic departures from non-differential sensitivity.

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  • Childhood maltreatment is linked to higher prepregnancy body mass index (BMI) among women, but its impact on gestational weight gain is less clear.
  • The study analyzed data from 656 women over a 20-year period, using modified Poisson regression to explore the relationship between different types of maltreatment and weight measures before and during pregnancy.
  • Findings indicate that certain forms of maltreatment, especially emotional abuse, significantly increase the chance of having a prepregnancy BMI of 30 or more, suggesting the need for targeted support for women with these experiences as they approach pregnancy.
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  • The study examines the link between social determinants of health and the risk of contracting COVID-19 among American Indian and Alaska Native (AI/AN) peoples, highlighting a lack of prior knowledge in this area.
  • A survey of 767 AI/AN patients revealed that living in multigenerational households increased the risk of contracting COVID-19 by 11 percentage points.
  • Additionally, participants who received tribal payments showed a reduced risk of COVID-19, suggesting that targeted interventions and financial support could improve health outcomes for urban AI/AN populations.
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Direct oral anticoagulants (DOACs; rivaroxaban, apixaban) and warfarin are approved for venous thromboembolism (VTE) treatment. Few direct comparisons of DOACs on risk of mortality among VTE patients exist, and for patients with concomitant conditions (e.g.

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Background: Prepregnancy body mass index (BMI) and gestational weight gain (GWG) are determinants of maternal and child health. However, many studies of these factors rely on error-prone self-reported measures.

Methods: Using data from Life-course Experiences And Pregnancy (LEAP), a US-based cohort, we assessed the validity of prepregnancy BMI and GWG recalled on average 8 years postpartum against medical record data treated as alloyed gold standard ("true") values.

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Background: Food insecurity is an important social determinant of health that was exacerbated by the COVID-19 pandemic. Both food insecurity and COVID-19 infection disproportionately affect racial and ethnic minority groups, particularly American Indian and Alaska Native communities; however, there is little evidence as to whether food insecurity is associated with COVID-19 infection or COVID-19 preventive behaviors such as vaccination uptake. The purpose of this study was to evaluate associations between food insecurity, COVID-19 infection, and vaccination status among urban American Indian and Alaska Native adults seen at 5 clinics serving urban Native people.

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Background: Food insecurity is an important social determinant of health that was exacerbated by the COVID-19 pandemic. Both food insecurity and COVID-19 infection disproportionately affect racial and ethnic minority groups, particularly American Indian and Alaska Native communities; however, there is little evidence as to whether food insecurity is associated with COVID-19 infection or COVID-19 preventive behaviors such as vaccination uptake. The purpose of this study was to evaluate associations between food insecurity, COVID-19 infection, and vaccination status among urban American Indian and Alaska Native adults seen at 5 clinics serving urban Native people.

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Venous thromboembolism (VTE) affects 1.2 million people per year in the United States. With several clinical changes in diagnosis and treatment approaches in the past decade, we evaluated contemporary post-VTE mortality risk profiles and trends.

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Systematic error from selection bias, uncontrolled confounding, and misclassification is ubiquitous in epidemiologic research but is rarely quantified using quantitative bias analysis (QBA). This gap may in part be due to the lack of readily modifiable software to implement these methods. Our objective is to provide computing code that can be tailored to an analyst's dataset.

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Article Synopsis
  • The study highlights that pregnancy-related mortality in the U.S. has significantly increased since 1990, with venous thromboembolism (VTE) contributing to about 10% of these deaths.
  • Researchers aimed to determine if preexisting autoimmune diseases increase the risk of postpartum VTE, analyzing a large dataset of over 757,000 individuals of childbearing age.
  • Findings revealed that postpartum individuals with autoimmune diseases had a higher incidence of VTE, especially those with systemic lupus erythematosus and Crohn's disease, indicating the need for enhanced monitoring and preventive care for this group after delivery.
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People living with HIV face multiple psychosocial challenges. In a large, predominantly rural Ethiopian region, 1799 HIV patients new to care were enrolled from 32 sites in a cluster randomized trial using trained community support workers with HIV to provide individual health education, counseling and social support. Participants received annual surveys through 36 months using items drawn from the Centre for Epidemiologic Studies Depression Scale-10, Medical Outcome Study Social Support Survey, and HIV/AIDS Stigma Instrument-PLWA.

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Background: Opioid-related mortality is an important public health problem in the United States. Incidence estimates rely on death certificate data generated by health care providers and medical examiners. Opioid overdoses may be underreported when other causes of death appear plausible.

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Background: Binge drinking can result in various types of harms including traffic crashes. Bars and restaurants that serve alcohol to patrons who are obviously intoxicated (i.e.

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Background Pulmonary hypertension (PH) is a devastating potential complication of pulmonary embolism, a manifestation of venous thromboembolism (VTE). The incidence of and risk factors for PH in those with prior VTE are poorly characterized. Methods and Results () codes from inpatient and outpatient medical claims from MarketScan administrative databases for years 2011 to 2018 were used to identify cases of VTE, comorbidities before the VTE event, and PH occurring subsequent to the VTE event.

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Objective: To estimate the prevalence of dementia among American Indian and Alaska Native (AIAN) Medicare beneficiaries and compare the prevalence of dementia in AIANs and other racial and ethnic minority groups-non-Hispanic Blacks (NHBs) and Hispanics-with non-Hispanic Whites (NHWs) Medicare beneficiaries.

Methods: We used survey data from Round 5 of the National Health and Aging Trends Study (NHATS, 2015) (N = 7,449), a nationally representative study of Medicare beneficiaries ages 65 years and older. We used logistic regression to estimate the age- and sex-adjusted prevalence of dementia with 95% confidence intervals by race/ethnicity as well as prevalence differences between groups.

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Background: Previous research has shown an association between individual thunderstorm events in the presence of high pollen, commonly called thunderstorm asthma, and acute severe asthma events, but little work has studied risk over long periods of time, using detailed measurements of storms and pollen.

Methods: We estimated change in the risk of asthma-related emergency room visits related to thunderstorm asthma events in the Minneapolis-St. Paul metropolitan area over the years 2007-2018.

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Although dementia and atrial fibrillation (AF) are common in older adults, risk factors for dementia have not been sufficiently characterized in patients with AF. We studied 621,773 patients with AF without dementia at the time of AF diagnosis who were enrolled in the MarketScan Commercial and Medicare Supplemental databases from 2007 to 2015. Dementia incidence and presence of predictors at the time of AF diagnosis (cardiometabolic conditions, mental and neurologic disorders, and other chronic conditions) were based on International Classification of Diseases, Ninth Revision, Clinical Modification codes in outpatient and inpatient claims, whereas medication usage was based on outpatient pharmacy claims.

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  • Retention in HIV care is critical for effective AIDS control, particularly in sub-Saharan Africa, where many patients struggle to stay engaged in their treatment.* -
  • In a study in Ethiopia, 1,799 HIV-positive patients were assigned to either receive support from community support workers (CSWs) or not, focusing on education, counseling, and social support.* -
  • After 36 months, the results showed no significant difference in gaps in care or mortality between the groups, suggesting that external factors like stigma and political instability may have hindered the expected benefits of the CSW intervention.*
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Data collected from a validation substudy permit calculation of a bias-adjusted estimate of effect that is expected to equal the estimate that would have been observed had the gold standard measurement been available for the entire study population. In this paper, we develop and apply a framework for adaptive validation to determine when sufficient validation data have been collected to yield a bias-adjusted effect estimate with a prespecified level of precision. Prespecified levels of precision are decided a priori by the investigator, based on the precision of the conventional estimate and allowing for wider confidence intervals that would still be substantively meaningful.

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Background: Women with atrial fibrillation (AF) experience greater symptomatology, worse quality of life, and have a higher risk of stroke as compared to men, but are less likely to receive rhythm control treatment. Whether these differences exist in elderly patients with AF, and whether sex modifies the effectiveness of rhythm versus rate control therapy has not been assessed.

Methods: We studied 135,850 men and 139,767 women aged ≥ 75 years diagnosed with AF in the MarketScan Medicare database between 2007 and 2015.

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