Publications

Many frequent emergency department (ED) users do not sustain high use over time, which makes it difficult to create targeted interventions to address their health needs. We performed a retrospective analysis of nonelderly adult frequent ED users in California to measure the persistence of frequent ED use in the period 2005-15, describe characteristics of persistent and nonpersistent frequent users, and identify predictors of persistent frequent use. Of the frequent ED users in 2005, 30.5 percent remained frequent users in 2006. A small but nontrivial population (16.5 percent, 5.7 percent, and 1.9 percent) exhibited persistent frequent use for three, six, and eleven consecutive years, respectively. The strongest predictor of persistent frequent ED use was the intensity of ED use in the baseline study year. The rate at which frequent users stopped using the ED frequently decreased over time, leaving a core group of chronic persistent users. These persistent frequent users differ from nonpersistent frequent users, who engaged in temporary intense use of the ED. Identifying and differentiating persistent frequent users is important, as they may be candidates for distinct interventions.

BACKGROUND

Strong evidence supports the role of both genetic and environmental factors in pediatric-onset multiple sclerosis (POMS) etiology.

OBJECTIVE

We comprehensively investigated the association between established major histocompatibility complex (MHC) and non-MHC adult multiple sclerosis (MS)-associated variants and susceptibility to POMS.

METHODS

Cases with onset <18 years ( n = 569) and controls ( n = 16,251) were included from the United States and Sweden. Adjusted logistic regression and meta-analyses were performed for individual risk variants and a weighted genetic risk score (wGRS) for non-MHC variants. Results were compared to adult MS cases ( n = 7588).

RESULTS

HLA-DRB1*15:01 was strongly associated with POMS (odds ratio (OR) = 2.95, p < 2.0 × 10). Furthermore, 28 of 104 non-MHC variants studied (23%) were associated ( p < 0.05); POMS cases carried, on average, a higher burden of these 28 variants compared to adults (OR = 1.24 vs 1.13, respectively), though the difference was not significant. The wGRS was strongly associated with POMS (OR = 2.77, 95% confidence interval: 2.33, 3.32, p < 2.0 × 10) and higher, on average, when compared to adult cases. Additional class III risk variants in the MHC region associated with POMS were revealed after accounting for HLA-DRB1*15:01 and HLA-A*02.

CONCLUSION

Pediatric and adult MS share many genetic variants suggesting similar biological processes are present. MHC variants beyond HLA-DRB1*15:01 and HLA-A*02 are also associated with POMS.