Effect of Age on Healthcare Utilization in Patients with Sickle Cell
Authors: Hamilton Nicholas , Desai Payal , Williams Nita , Moore Mikaela D. , Schamess Andrew I. 
Published: November 2019

Background: The median life expectancy of patients with sickle cell disease surpassed 40 years of age in the last two decades. While sickle cell patients overall are known to have high utilization of health services due to vaso-occlusive pain crises (VOC), few studies have focused on the impact of age on utilization pattern. Due to this, our understanding of the patient population is frequently skewed based on data on younger patients. This study examines the utilization of healthcare in patients in two groups: below 40 years of age, and 40 years and over. We also examined the impact on these two cohorts of a home-based primary care program.
Methods: All patients were enrolled in a home-based primary care program in which their primary care doctor visited their home every 4-6 weeks. Health utilization data were collected retrospectively, through chart review for one year prior to joining the home-based primary care program, and prospectively for one year after joining the program. Primary care appointments, reported crises, Sickle Cell Day Hospital visits, ED visits, admissions, 30-day readmissions, and total admission days were recorded.
Results: A total of 30 patients was enrolled in the study, and 58 years of data were collected. There were 16 patients between 18 and 39, and 14 patients aged 40 and over. 50% of the 40 and over age group was SS genotype and 50% SC compared to only one patient in the below 40 population had genotype SC. The groups were not significantly different regarding gender distribution (57% female in the 40 and over population vs 50% female in the below 40 population). The 40 and over population had on average more comorbidities per patient. The 40 and over population had significantly more primary care visits every year both before and after the start of the home visits compared to the below 40 population,. The 40 and over population, also had significantly lower overall rates of acute care utilization than the patients under 40: number of crises, ED visits, admissions, 30-day readmissions, and total hospital admission days. When comparing pre and post home visiting within the 40 and older population, there was an increase in primary care visits and a decrease in in reported crises, ED visits, admissions and readmissions. There was no change in these parameters in the 18-39 year old patient group.
Discussion: As sickle cell patients age, they are more likely to have cumulative co-morbidities due to their sickle cell disease. Despite their more advanced age and their increase in co-morbid conditions, patients 40 and above were shown in our study to have fewer ED visits and admissions than younger patients, and to further reduce ED visits and admissions when provided with home-based primary care. The younger group had higher utilization at baseline, and did not show improvement when receiving home-based primary care. The reduced acute care utilization in the older group could be due to increased use of primary care, which was further enhanced by enrollment in the home-based primary care program; better adherence to medical treatment; more skill and experience in disease self-management; better social support; or fewer vaso-occlusive crises despite a higher number of co-morbid conditions. The higher prevalence of SC disease in the older cohort is a possible confounder. Those patients with higher utilization at a younger age may be higher risk of mortality, thereby leading to a survivor effect in the older population. Research in the general medical population has shown that home-based primary care reduces acute care utilization in high-utilizing patients with multiple chronic conditions, but more research is needed on the impact in sickle cell patients.
Conclusion: This is the first study, to our knowledge, of the impact of home-based primary care on adults with sickle cell disease. In this study, sickle cell patients aged 40 and under showed overall more acute care utilization than those over age 40. The older population had an increase in primary care visits, and overall a significant decrease in healthcare utilization after enrollment in the home visiting program. We did not see a significant decrease in utilization in the younger population with home visits.

Disclosures
Desai: Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Ironwood: Other: Adjudication Board; University of Pittsburgh: Research Funding; Novartis: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Potomac: Speakers Bureau.