Which Neighborhood-level Metric Is Most Appropriate for Pediatric Sports Medicine Disparities Research?

Neighborhood conditions are associated with access to care and outcomes. The Child Opportunity Index (COI) and Area Deprivation Index (ADI) are commonly used in pediatric research but without a clear rationale as to why one is chosen over the other. Despite an increasing volume of health equity research, there is little evidence that has directly compared the ADI and COI's associations with previously established pediatric orthopaedic disparities. Thus, the most appropriate neighborhood-level measure for pediatric orthopaedic research remains unclear.

(1) Do COI and ADI correlate with each other? (2) How do COI and ADI compare in their associations with previously established pediatric orthopaedic disparities, including time to ACL reconstruction (ACLR) and the presence of concomitant meniscal and chondral pathology?

This is a retrospective, comparative study of patients aged 18 years or younger who underwent primary ACLR between 2010 and 2023 at one tertiary center. We excluded patients who were missing COI or ADI data. Patients who underwent multiligament reconstruction, revision ACLR, intentionally staged or delayed procedures, or previous surgery on either knee were also excluded. We initially considered 806 patients, of whom 9% (72) were excluded for prespecified reasons. Consequently, 734 patients were included in the study (mean ± SD age was 16 ± 2 years and 52% [382] were boys). The median (IQR) time between injury and surgery was 74 days (82). Fifty-five percent (401) of patients had public insurance (Medicaid), 42% (306) had private insurance, and 4% (27) had no insurance or other types of insurance. The COI and ADI scores were assigned by address at the time of surgery. The COI quantifies neighborhood resources with 44 indicators across three domains: education, health and environment, as well as social and economic. It is scored from 0 to 100, with 0 indicating the lowest level of neighborhood resources. The ADI quantifies socioeconomic deprivation with 17 indicators across four domains: education, income, employment, and housing quality. It is also scored from 1 to 100, with 100 indicating the highest level of deprivation. Only national-level COI and ADI scores were used, given that the ADI does not provide continuous data at the state and metropolitan levels. The mean ± SD COI and ADI scores for the study population were 50 ± 29 and 44 ± 22, respectively. Outcomes of interest included time to surgery and intraoperative concomitant pathology. The Pearson correlation coefficients (r) were calculated for the comparison of continuous variables. Negative r values indicate inverse relationships (for example, a negative value suggests that as the value of one variable increases, the other decreases). By convention, an r value of 1 is a perfect correlation, 0.7 < r < 1 is a strong correlation, 0.3 < r < 0.7 is a moderate correlation, and 0 < r < 0.3 is a weak correlation. Regression analyses, reported with regression coefficients or ORs and 95% confidence intervals (CIs), assessed the association of the COI or ADI with clinical outcomes (timing of surgery and concomitant meniscal or chondral pathology) while controlling for confounders.

The COI and ADI demonstrated moderate correlation with each other (r = -0.69; p < 0.001), indicating that an increasing COI score (for example, more neighborhood opportunity) correlates with a decreasing ADI score (for instance, less neighborhood deprivation). After controlling for insurance and time to surgery, when applicable, a higher COI score (indicating higher level of neighborhood opportunity) was associated with a shorter time to ACLR (regression coefficient -0.56 [95% CI -0.95 to -0.16]; p = 0.006); lower odds of concomitant meniscectomy (OR 0.99 [95% CI 0.98 to 0.99]; p = 0.02); and surgery beyond 60 days (OR 0.99 [95% CI 0.98 to 0.99]; p < 0.001), beyond 90 days (OR 0.99 [95% CI 0.98 to 0.99]; p < 0.001), and beyond 180 days (OR 0.99 [95% CI 0.98 to 0.99]; p = 0.02) after injury. In separate multivariable models, a higher ADI score (indicating a higher level of deprivation) was associated with increased odds of surgery beyond 60 days (OR 1.02 [95% CI 1.01 to 1.03]; p < 0.001) and 90 days (OR 1.02 [95% CI 1.01 to 1.02]; p < 0.001) after injury, but no other outcomes that we assessed.

In the context of pediatric ACLR, the results suggest that the COI may be more appropriate than the ADI in identifying pediatric-specific disparities in sports medicine. This may be due to differences in the types and number of underlying indicators contributing to each index and the underlying methodologies used in each index's development. Additionally, continuous ADI data are only available on the national scale.

These findings highlight the importance of selecting appropriate neighborhood-level indices when conducting disparities research. Consideration should be given to the underlying components of these indices and their potential relevance to the population of interest and research question. Future research should focus on comparing the COI and ADI in other clinical contexts to assess the generalizability of these findings and better inform future research methodology.