High Cotinine and Healthcare Utilization Disparities Among Low-Income Children

Introduction: This study assesses the associations of child salivary cotinine, parent-reported smoking, and child tobacco smoke exposure with the number of child healthcare visits and hospital admissions over a 6-month period. This study also assesses the relationships between participant characteristics and child cotinine.

Methods: Longitudinal data were evaluated from a sample of 313 clinically ill children aged 0-9 years who lived with a smoker and presented to a pediatric emergency department or urgent care in 2016-2018. In 2020, cotinine measurements were log transformed, and Poisson and linear regression were performed.

Results: The majority of the children came from low-income homes (66.1%) and had public insurance/self-pay (95.5%). Child cotinine concentrations ranged from 0.1 to 332.0 ng/mL (geometric mean=4.8 ng/mL, 95% CI=4.1, 5.5). Poisson regression results indicated that each 1-unit increase of log-cotinine concentration was associated with an increase in pediatric emergency department visits over a 6-month period after the baseline visit, with an adjusted RR of 1.16 (95% CI=1.01, 1.34). Each 1-unit increase of log-cotinine concentration was associated with an increase in the frequency of hospital admissions over the 6-month period, with an adjusted RR of 1.50 (95% CI=1.08, 2.09). No differences were found between parent-reported smoking or child tobacco smoke exposure and healthcare utilization. Linear regression results indicated that children who were younger (β= -0.227, p=0.049), were White (geometric mean=5.5 ng/mL), had a medical history of prematurity (geometric mean=8.1 ng/mL), and had a winter baseline visit (geometric mean=6.5 ng/mL) had higher cotinine concentrations. Children living in apartments (geometric mean=5.5 ng/mL) and multiunit homes (geometric mean=5.5 ng/mL) had higher cotinine concentrations than those in single-family homes (geometric mean=3.6 ng/mL).

Conclusions: Routine biochemical screening could identify children who are in need of intensive tobacco smoke exposure reduction interventions.