Extreme Temperatures and Missed Pediatric Preventive Care Visits.

Importance: Missed pediatric preventive care visits can delay essential developmental screenings, immunizations, and management of chronic conditions, adversely impacting child health. Understanding the relationship between extreme temperatures and missed preventive care is essential for developing adaptive strategies to maintain care access amid increasing climate variability. Objective: To assess the association of extreme temperatures with rates of missed pediatric preventive care visits and evaluate differences by patient age, insurance, and neighborhood socioeconomic status (SES). Design, Setting, and Participants: This cross-sectional time-series study used electronic health record data of patients aged younger than 19 years with scheduled preventive care visits at 32 primary care practices in the Children's Hospital of Philadelphia primary care network in Pennsylvania and New Jersey from January 1, 2009, to December 31, 2023. Statistical analyses were completed between March and October 2025. Exposure: Daily maximum temperature (°F), derived from the National Oceanic and Atmospheric Administration's weather stations and averaged at the county level for each practice. Main Outcome and Measures: Daily rate of missed preventive care visits (the proportion of scheduled visits resulting in same-day cancellation or no-show). Generalized linear quasi-Poisson models estimated associations of daily maximum temperature (in °F) with daily rate of missed preventive care visits overall and stratified by age, insurance, and neighborhood SES. Associations were evaluated separately for warm (May-October) and cold (November-April) months. Heterogeneity across strata was evaluated using the Cochran Q test. Results: Among 504 428 patients, 51% were male, 36% had public insurance, and 27% were from very low SES neighborhoods. Mean (SD) patient age was 6.0 (5.7) years. Among 4 137 542 scheduled preventive care visits, 13% were missed. Each 1 °F decrease below a maximum daily temperature of 41.5 °F in cold months and 1 °F increase above 88.0 °F in warm months was associated with a higher rate of missed visits (rate ratios, 1.01 [95% CI, 1.01-1.01] and 1.01 [95% CI, 1.00-1.01], respectively). Significant heterogeneity in missed visits across age, payer, and neighborhood SES was observed in cold months, with higher rates of missed visits among patients with commercial vs public or other types of insurance (RR, 1.02; 95% CI, 1.02-1.02) as well as among younger patients and those from high SES neighborhoods. Conclusions and Relevance: In this cross-sectional study, extreme outdoor temperatures were associated with increased rates of missed pediatric preventive care visits, with heterogeneity across age, payer, and neighborhood SES during cold months. The findings suggest proactive scheduling strategies and alternative care delivery models should be assessed to maintain access to essential pediatric preventive care services during temperature extremes.