Sickle Cell Disease May Qualify As an Ambulatory Care Sensitive Condition

Background Ambulatory care sensitive conditions (ACSCs) are conditions for which outpatient care can potentially prevent hospital visits.[i] Effective primary care is associated with lower hospitalization for ACSCs. These hospitalizations are also referred to as avoidable hospitalization.[ii] [iii] We hypothesized that sickle cell disease (SCD) qualifies as an ACSC. We partly tested that hypothesis in the context of an intense primarily ambulatory case management program that also includes urgent and inpatient management components.

Methods As part of a SCD Adult Medical Home with multiple interventions, we assigned Community Health Workers (CHWs), called Patient Navigators (PNs), as case managers. A PN (one of two in 2018, and one of three in 2019, 2020, and 2021) was assigned to each of the program's top 50 highest utilizers, but also began periodically managing other patients ad hoc in 2019 (All adult patients, N=537 in 2017 to N=641 in 2021). Activities focused on education to improve self-care, assisting patients with medical appointments, and accessing services to combat adverse social determinants. PNs strove to reduce avoidable emergency department (ED) visits and hospitalizations. Interventions and visit activity included telephone, face-to-face clinic, face-to-face ED, face-to-face inpatient, or face-to-face community contact (restricted to telecommunication by COVID). Data and analyses from 2017 to 2021 included: 1) Spearman's correlation of inpatient discharges with outpatient visits; 2)Spearman's correlation of annual ED visits with annual outpatient visits; 3)calculation of ED Reliance Ratio (ERR, defined as ED visits/ED + ambulatory + inpatient visits), Spearman's correlation of ERR with annual costs, and ANOVA test for significance of ERR decreasing; 4) Spearman's correlation between costs and Inpatient discharge, and ANOVA test for significance of inpatient discharge decreasing.

Results 1)Inpatient discharges started to drop with the increased outpatient visits in 2018 for all patients. Due to COVID-19, no significant inverse correlation was observed. However, an inverse Correlation between Inpatient Discharge vs. Outpatient Visit for top 50 utilizers was statistically significant (Spearman R=-0.17, p-value=0.02).

2) Spearman correlation did not show significant inverse correlation between ED_usage and outpatient visit for all patients due to suspected COVID effects. However, annual ED visit is almost inversely correlated with annual outpatient visits for the top 50 utilizers (Spearman R=-0.13, p =0. 05).

3)Total costs correlated with the ERR for 2017-2021, both for each year's top utilizers (Spearman R=0.40, p <0.0001), and for all patients (Spearman R=0.44, p<0.0001). ERR has been significantly decreased from 2017 to 2021 for all patients (ANOVA P=0.0089<0.05) and for top 50 utilizers (ANOVA P<0.0001).

4)In addition, the inpatient discharge positively correlated with total cost both for each year's top utilizers (Spearman R=0.70, p <0.0001), and for all patients (Spearman R=0.71, p<0.0001). The number of Inpatient hospitalizations decreased significantly. ANOVA shows p<0.0001 for both all patients and for top 50 utilizers.

Conclusions Sickle cell disease appears to behave as an ACSC in our SCD sample. An intervention led to fewer ED visits and avoidable hospitalization. Annual total costs decreased accordingly during that same period. But some statistically expected utilization relationships were not observed. Future post-COVID utilization may confirm these findings, and studies of ACSC interventions with control groups in SCD patients may increase the validity of our before-after findings of intervention effects.

1. AHRQ Quality Indicators. Guide to prevention quality indicators: hospital admission for ambulatory care sensitive conditions. Rockville: Agency for Healthcare Research and Quality; 2001. AHRQ Pub. No. 02-R0203.

2. Gao J, Moran E, Li YF, et al. Predicting potentially avoidable hospitalizations. Med Care 2014 Feb;52(2):164-71

3. Chartbook on Care Coordination: Potentially Avoidable Hospitalizations. Agency for Healthcare Research and Quality. https://www.ahrq.gov/research/findings/nhqrdr/chartbooks/carecoordination/measure3.html

Smith:Novo Nordisk: Other: DSMB; Novartis: Consultancy, Honoraria; Global Blood Therapeutics: Consultancy, Honoraria, Research Funding, Speakers Bureau; Emmaus: Consultancy; Forma Therapeutics: Consultancy, Research Funding; Agios: Research Funding; Pfizer: Consultancy, Research Funding; Imara: Research Funding.