SCDAA 46th Annual National Convention

Abstract

Authors:
Dr. Arlene Smaldone, Columbia University School of Nursing, Dr. Deepa Manwani, The Children's Hospital at Montefiore,  Dr. Nancy S. Green, Columbia University Medical Center  

Objective:  The purpose of this study was to examine the effect of a community health worker (CHW) intervention on reduction of self-reported barriers to hydroxyurea (HU) adherence in a sample of poorly adherent youth ages 10-17 years who participated with their parent in the Hydroxyurea Adherence for Personal Best in Sickle Cell Disease "HABIT" feasibility trial. Dyads randomized to the intervention worked with CHWs to develop a HU habit reinforced by daily personized text messages.
Methods: We modified the Adolescent Medication Barriers Scale (AMBS) (17 items) and its parent counterpart, Parent Medication Barriers Scale (PMBS) (16 items) for use with HU by adding 9 items regarding HU beliefs.  Three subscales (Disease frustration, Regimen adaptation, Ingestion Issues) are common to both scales; the parent scale has an additional subscale (Reliance on parent reminders). Youth and parents completed the measure at 0, 3 and 6 months in either Spanish or English. Youth and parent proxy reported generic (PedsQL) and disease specific (PedsQL Sickle Cell module) HRQL were measured at the same intervals. Data were analyzed using Cronbach's alpha, descriptive statistics, spearman correlation coefficients and linear growth models controlling for group assignment and time.
Results: 28 parent youth dyads (50% Latino, youth 43% female, age 14.3 ± 2.6 years) participated. Internal reliability was high for both parent (alpha=0.88) and youth (alpha=0.91) total scales and all subscales except the parent ingestion subscale (alpha=0.30). On average, parents and youth acknowledged 3.5±3.2 and 5.0±3.9 total barriers (possible score 0-25 youth; 0-26 parents) respectively. Adherence barriers most frequently reported by parents were child overreliance on parent reminders [42.9%]; adolescent frustration (child tired of living with SCD [35.7%]); regimen adaptation problems (finding it hard to stick to a medication schedule [28.6%]); and HU beliefs (parent concern about possible adverse HU effects on fertility or on a fetus [25%]). Youth most frequently reported barriers were related to adolescent frustration (tired of living with SCD [57.1%]; being forgetful and not always remembering to take HU [53.6%], tired of taking HU [39.3%], not wanting to take HU at school [28.6%], and not wanting to be seen taking HU [25%],); ingestion issues (HU hard to swallow [25%], too many pills to take [39.3%], dislikes HU taste [35.7%]); and regimen adaptation problems (not organized about when and how to take HU [28.6%]). Parent and youth responses were moderately correlated for the total scale (r=0.50, p<0.001) and all subscales except HU beliefs (r=0.08, p=0.51). Greater number of barriers were associated with lower generic (parent r=-0.43, p=0.03; youth r=-0.44, p<0.001) and disease specific (parent r=-0.53, p=0.005; youth r=-0.53, p<0.001) HRQL. Controlling for group assignment and time, intervention parents demonstrated a trend in less reported adolescent frustration (p=0.18) at 6 months whereas for adolescents assigned to the intervention group, ingestion related barriers significantly declined (0.17/month, p=0.02) over 6 months. Total barriers and other subscales did not significantly change. 
Conclusions: Barriers to adherence are prevalent, multi-faceted and perceived differently by youth prescribed HU and their parents. Greater barriers were associated with poorer youth and parent-proxy reported generic and disease specific HRQL. Some barriers, e.g. problems with ingestion, are potentially modifiable. A CHW delivered intervention helped youth reduce their ingestion barriers to HU use. To derive the full value of HU in youth with SCD, barriers to its use must be addressed with both youth and parents.