Spatial and nonspatial barriers to Undiagnosed Diseases Network acceptance: Implications for accessing research

Abstract

Objectives. To assess, geographic, non-spatial, clinical, and demographic barriers to acceptance to the Undiagnosed Disease Network, an NIH common fund study that seeks to provide answers for families and individuals affected by undiagnosed or rare conditions, and to assess the interaction between spatial and non-spatial variables on UDN acceptance. Methods. The study consisted of data from the UDN gateway of 2415 Phase I applicants. The association between spatial and non-spatial variables and UDN acceptance was assessed using multivariable logistic regression. We additionally assessed the interaction between spatial and non-spatial variables and UDN acceptance using multivariable logistic regression. A Hot Spot Analysis was conducted to determine regions of applicant spatial clustering based on median annual income. Hot Spot analysis aids in visualizing possible areas in which economic burden of undiagnosed or rare diseases may be higher or lower for UDN applicants. Results. Of the 2415 Phase I applicants, 182 (49%) were accepted and 1233 (51%) were not accepted. Increased age at application submission was associated with decreased odds of acceptance. Asian applicants were more likely to be accepted than white applicants, and Spanish-speaking individuals were more likely to be accepted than English-speaking individuals. There were no statistically significant interaction effects between spatial and non-spatial variables on UDN acceptance, and we found no evidence of geographic barriers of acceptance. The Southern and Midwest parts of the US indicate cold spots of low median income and the Northeast and Pacific Coastal regions of the US were hot spots with high median income. Conclusions. Despite the long distances families travel to access the UDN, no geographic disparities in acceptance to the UDN were identified in this study. Further, we did not identify disparities by race in acceptance to the UDN, and Spanish-speaking individuals were actually more likely to be accepted. Future research to understand barriers to recruitment and completing an application is warranted.