Healthcare utilization and hydroxyurea adherence in youth with sickle cell disease

Background: Sickle cell disease (SCD) complications lead to poor health-related quality of life (HRQOL) and increased healthcare utilization in this population, which could be mitigated with hydroxyurea therapy; however, adherence is suboptimal. We assessed the relationship of healthcare utilization to hydroxyurea adherence and HRQOL amongst youth with SCD.Methods: Thirty-four patients with SCD (median age 14 years, IQR 12-18) on hydroxyurea participated in this cross-sectional study and completed Morisky Adherence Scale 8-items and Patient Reported Outcomes Measurement Information System (PROMIS (R)) HRQOL measures. A medical chart review was conducted to assess healthcare utilization.Results: Participants with more frequent hospitalizations and emergency room (ER) visits and longer length of stay (LOS) had significantly lower fetal hemoglobin (r(s)=-0.44; r(s)=-0.45; r(s)=-0.46, p<0.05) and mean corpuscular volume (r(s)=-0.47; r(s)=-0.42; r(s)=-0.48, p<0.05), respectively. More frequent hospitalizations and ER visits and longer LOS correlated significantly with worse fatigue (r(s)=0.51; r(s)=0.41; r(s)=0.53, p<0.05), pain (r(s)=0.41; r(s)=0.38; r(s)=0.47, p<0.05), physical function mobility (r(s)=-0.67; r(s)=-0.59; r(s)=-0.67, p<0.05), depression (r(s)=0.38; r(s)=0.31; r(s)=0.42, p<0.05), and social isolation (r(s)=0.76; r(s)=0.76; r(s)=-0.84, p<0.05), respectively.Conclusions: We conclude that increased healthcare utilization in youth with SCD is associated with low adherence to hydroxyurea and worse HRQOL domain scores. It is important emphasize the clinical benefits of high adherence to hydroxyurea, particularly among youth with SCD. Future longitudinal studies are warranted to assess the directionality of these relationships, and may reveal modifiable behavioral factors associated with early changes in hydroxyurea adherence levels.