Caregiver's health locus of control and medication adherence in sickle cell disease

Acknowledgements: The authors would like to thank Dr. Morisky for giving us permission to use the Morisky Medication Adherence Scale Purpose: To explore caregivers' Health Locus of Control's relationship to selfreported adherence to penicillin prophylaxis or hydroxyurea in children with sickle cell disease (SCD). Procedure: A questionnaire-based study was conducted of caregivers of children with SCD who visited a comprehensive sickle cell center in an inner city hospital, who were either on penicillin prophylaxis or hydroxyurea or both. Multidimensional Health Locus of Control Scale (MHLC) and the Morisky Medication Adherence Scale (MMAS-8) questionnaires were used for the study. Results: Caregivers of 43 children (27 on penicillin prophylaxis, 13 on hydroxyurea, and 3 on both) completed the MHLC and the MMAS-8. There was no significant difference in adherence between the penicillin and the hydroxyurea groups. The mean Powerful Others score of caregivers of the hydroxyurea only group (25.5+5.6) was higher than that of the penicillin only group (21.2+6.1, p=0.043). Regression analysis revealed an inverse relationship of Chance Locus of Control to adherence in the entire group (Beta =-0.306, R2=0.093, F[1,40]=4.12, p=0.049). Conclusion: Chance Locus of control may identify caregivers of children with SCD at risk for non-adherence to treatment.