A Medical Home Model with Overlap of Pediatric and Adult Care Mitigates the Upsurge in Health Care Utilization Post-Transfer to Adult Care in Sickle Cell Disease

Introduction: Most children with sickle cell disease (SCD) today survive into adulthood; however health care utilization (HCU – acute care/emergency department visits and hospitalizations) is highest following transfer to adult care. The upsurge in HCU is due to disease progression but also due to difficulty in establishing a suitable medical home following pediatric care. To address the inadequate placement into adult care, two independent SCD programs, one adult and one pediatric, partnered to create the Young Adult Transition Clinic (YATC) in January 2012 for patients with SCD ages 18 to 25. The YATC is located at the adult hospital and portends two levels of overlap between pediatric and adult care: 1) co-management by a Pediatric Hematologist and an Internist, and 2) case-management by a nurse coordinator who initiates case-management in the pediatric setting at age 17 and continues in the adult setting until age 25. All visits followed a detailed plan-of-care including systematic orientation to adult care, disease-related education, and self-management strategies.

Hypothesis: We hypothesized that overlapping pediatric and adult care can prevent the expected increase in HCU rates following transfer to adult care, while maintaining high patient retention and adequate health literacy levels.

Methods: Incidence rates (IR) and incidence rate ratios (IRR) for HCU and health maintenance visits were estimated and compared for the 2-year interval preceding departure from pediatric care, and the first 2 years following transfer to adult care using a repeated measures model for HCU counts, which accounts for different individual exposure time. Disease-specific health literacy was measured using a 10-question survey regarding SCD pain management before (pre-score) and immediately after (post-score) an educational session by the nurse coordinator during both pediatric and adult care. Health literacy results were compared using Wilcoxon signed rank test.

Results: From January 2012 to July 2014, 59 young adults with SCD (HbSS=31, HbSC=18, HbSβ⁺thalassemia=7, HbS/HPFH=2, HbSβ⁰thalassemia =1) initiated care at YATC within 3 months from leaving pediatric care. Their median age upon start of observation period was 16.3 years (range, 15.5 to 17.8). The median exposure time during pediatric care (pre-exposure time) was 2 years, and the median exposure time during adult care (post-exposure time) was 1.9 years (IQR = 1.2–2.0). The IRR for HCU between pediatric and adult care did not change significantly 1.13 (95%CI 0.78, 1.63, IR 1.78 and 2.00, respectively). IR for health maintenance visits decreased from 6.31 in pediatric to 4.28 during adult care, IRR 0.68 (95%CI 0.57, 0.81). The 30-day readmission rate decreased from 33% to 23% after transfer to adult care, and there was no change in median length of hospitalization (3 days for both pediatric and adult care). Adolescents and young adults significantly improved their medical knowledge regarding SCD pain following the educational session in clinic (median scores improved from 80% to 100%, and from 90% to 100% for pediatric and adult care, respectively, p<0.0001). Pre-education median pain scores were significantly higher during adult care than during pediatric care (80% versus 90%, p<0.0001), and there was no significant decline in scores in the mean 12 months after the pediatric (post-score) and before the adult educational session (pre-score) (100% versus 90%, p=0.12), denoting knowledge retention. The overall attrition rate for YATC was 8.5%; one lost to follow-up, four transferred to another provider for insurance policy change (n=2) or personal request (n=2). There was one death due to multi-organ failure. Among the 32 HbSS/HbSβ⁰ subjects, the proportion of those treated with hydroxyurea increased from 53% pre-transition to 69% post-transition (p-value=0.0625).

Conclusion: A medical home model for young adults with SCD with merging of pediatric and adult care prevents the expected upsurge in HCU and increase in 30-day readmission rate, promotes adequate medical literacy levels, high hydroxyurea utilization, and affords high retention rates. Rates for health maintenance visits decreased after transfer to adult care, likely reflecting different schedule of visits. Continued longitudinal follow-up is necessary to demonstrate long-term effectiveness of this medical home model.