Publications by authors named "J M Knudson"

Objectives: To describe children with medical complexity (CMC) in Montana according to their clinical characteristics, rurality and distance from specialty care, and to assess for disparities in geographic access to specialty care for American Indian children.

Methods: In this cross-sectional study we categorized children in 2016-2021 Montana Medicaid claims data using the Pediatric Medical Complexity Algorithm and compared the associations of medical complexity and demographic traits using Chi-squared tests. Using a database of providers we calculated drive times from children's residences to the nearest pediatric subspecialist and calculated bootstrap confidence intervals for the difference in median driving distances by complexity and race.

View Article and Find Full Text PDF

Background: Western Montana, USA, experiences complex air pollution patterns with predominant exposure sources from summer wildfire smoke and winter wood smoke. In addition, climate change related temperatures events are becoming more extreme and expected to contribute to increases in hospital admissions for a range of health outcomes. Evaluating while accounting for these exposures (air pollution and temperature) that often occur simultaneously and may act synergistically on health is becoming more important.

View Article and Find Full Text PDF

Background: Sickle cell disease, a common genetic disorder in African Americans, manifests an increased risk of sudden death, the basis of which is incompletely understood. Prolongation of heart rate-corrected QT (QTc) interval on the electrocardiogram, a standard clinical measure of cardiac repolarization, may contribute to sudden death by predisposing to ventricular tachycardia.

Methods: We established a cohort study of 293 adult and 121 pediatric sickle cell disease patients drawn from the same geographic region as the Jackson Heart Study (JHS) cohort, in which significant correlates of QT duration have been characterized and quantitatively modeled.

View Article and Find Full Text PDF

Background: Western Montana, USA, experiences complex air pollution patterns with predominant exposure sources from summer wildfire smoke and winter wood smoke. In addition, climate change related temperatures events are becoming more extreme and expected to contribute to increases in hospital admissions for a range of health outcomes. Few studies have evaluated these exposures (air pollution and temperature) that often occur simultaneously and may act synergistically on health.

View Article and Find Full Text PDF

Background: Sickle cell disease (SCD) is a common inherited blood disorder among African Americans (AA), with premature mortality which has been associated with prolongation of the heart rate-corrected QT interval (QTc), a known risk factor for sudden cardiac death. Although numerous genetic variants have been identified as contributors to QT interval prolongation in the general population, their impact on SCD patients remains unclear. This study used an unweighted polygenic risk score (PRS) to validate the previously identified associations between SNPs and QTc interval in SCD patients, and to explore possible interactions with other factors that prolong QTc interval in AA individuals with SCD.

View Article and Find Full Text PDF