Area Deprivation Index as an Additive Marker of Postdischarge Care Vulnerability in Pediatric Acute Hematogenous Osteomyelitis.

Background: Acute hematogenous osteomyelitis (AHO) in children requires prolonged antibiotic therapy and structured follow-up. However, successful treatment depends not only on medical management but also on consistent adherence to antibiotics and outpatient care. Socioeconomic disadvantage may influence a family's ability to complete treatment and attend follow-up appointments. The Area Deprivation Index (ADI) is a validated measure of neighborhood-level socioeconomic disadvantage and may help identify disparities in treatment continuity. This study sought to determine whether higher ADI scores were associated with (1) documented antibiotic adherence, (2) increased loss to follow-up, and (3) differences in clinical severity or treatment burden among pediatric patients with AHO. Methods: A retrospective cohort study was conducted on pediatric patients (≤18 years) with AHO treated at Phoenix Children's Hospital from January 2018 through January 2025. Clinical, demographic, and socioeconomic data, including state and national ADI scores based on patient postal codes, were extracted from the electronic medical record. Outcomes included antibiotic completion, follow-up adherence, length of stay, surgical interventions, and complications. Associations were evaluated using ADI quartiles, continuous analyses, and multivariable logistic regression adjusting for demographic, socioeconomic, and access-related factors. Results: Higher ADI levels demonstrated significant unadjusted gradients in antibiotic completion and loss to follow-up. Documented antibiotic completion decreased from 90.9% in the least-deprived quartile to 57.9% in the most-deprived, and loss to follow-up increased from 5.9% to 39.5% across the same gradient. In multivariable models adjusting for race/ethnicity, insurance status, geographic access, and clinical factors, these associations were attenuated and were not statistically significant, although effect estimates remained directionally consistent. ADI was not associated with inpatient disease severity, operative burden, readmission, or documented long-term complications. Conclusions: Neighborhood deprivation is associated with meaningful unadjusted disparities in postdischarge care continuity among children with AHO. After adjustment, these relationships appear to reflect overlapping structural factors rather than an independent effect. ADI may therefore serve as an additive risk-stratification tool to identify patients who may benefit from targeted support during the transition to outpatient care. Key Concepts: (1)The Area Deprivation Index (ADI) is a validated measure of neighborhood-level socioeconomic disadvantage that may identify vulnerability in postdischarge care among children with acute hematogenous osteomyelitis (AHO).(2)In this single-center pediatric cohort, higher ADI was associated with significantly lower antibiotic completion and higher loss to follow-up in unadjusted analyses.(3)Antibiotic completion decreased from 90.9% to 57.9%, and loss to follow-up increased from 5.9% to 39.5% across increasing ADI quartiles.(4)After adjustment for race/ethnicity, insurance status, and geographic access, ADI was not independently associated with antibiotic completion or loss to follow-up, although effect estimates remained directionally consistent.(5)These findings suggest that ADI reflects overlapping structural determinants of care and may serve as an additive tool to identify patients who could benefit from targeted postdischarge support. Level of Evidence: III, Prognostic Study.