Longitudinal Trend in Emergency Department Reliance for Pain Among Sickle Cell Disease Patients in Wisconsin.

Patients with sickle cell disease frequently visit the emergency department for pain. The metric of emergency department reliance (EDR) describes emergency department utilization in relation to all ambulatory visits and serves as a quality of care indicator. This study uses Wisconsin Medicaid data from 2011 to 2015 to examine trend of EDR for pain over the period of 5 years. We stratified our cohort (N=750) by patient ages into 4 groups: (1) children; (2) transition group; (3) young adults; and (4) adults. Using a linear mixed model, we estimated longitudinal trends adjusting for age group and hydroxyurea possession calculated as medication possession ratio. Results show that EDR for pain has distinct temporal patterns for each group. EDR for pediatrics continually remained less than the established threshold of 0.33. The EDR for transition group significantly increased over time; however, the EDR for young adults has significantly decreased since 2011. There were no significant differences in EDR over time for adults older than 30 years. Overall, increase in medication possession ratio was associated with lower EDR. The low EDR for pain among children and the improvements among adults indicate the success of efforts for sickle cell disease patients. However, further interventions are needed for the transition age group.