The Impact of an Acute Vaso-Occlusive Crisis on Patient Reported Outcomes: The Magic Study

Acute vaso-occlusive crises (VOC) are the most common complication in sickle cell disease (SCD) and frequently result in hospitalization. The impact of an acute VOC on patient reported outcomes (PROs) over time is not known. It is necessary to describe the patterns of change over time of these outcomes for future interventions that aim to optimize PROs. The objective of this study was to determine the impact over time of an acute VOC on the health-related quality of life (HRQL-a specific type of PRO) of children with SCD.

A multi-center prospective trial was conducted within the setting of a randomized controlled trial (the Magnesium in Crisis or MAGiC trial) that recruited from eight United States Children’s hospitals. Eligibility criteria included children ages 5 to 21 years with hemoglobin SS disease or β⁰thalassemia who were admitted to the hospital for a VOC and required intravenous administration of opioids. The children were asked to complete the PedsQL SCD and Fatigue HRQL modules at four time points (T0= at time of admission to hospital, T1= 48 hours from admission, T2= approximately 7 days post discharge, T3= steady state – complete resolution of the acute event, one month or more from discharge). The primary outcomes were the SCD and Fatigue Total HRQL scores. Secondary analyses examined specific HRQL domain scores. HRQL scores range from 0-100 with higher scores representing better HRQL. HRQL scores of 60-80 represent intermediate functioning. Descriptive statistics including t-tests for paired differences in scores were performed and a multivariate analysis using a linear mixed effects model was used to determine significant differences. The following covariates were included in the model: hospital site, age, gender, hydroxyurea use, disease severity (ever had acute chest syndrome and/or hospitalized for 3 or more VOC in the prior 3 years), and steady state HRQL score.

A total of 204 children participated in the trial. The mean age was 13.6 years and 51% were female. The mean SCD total HRQL scores over time were as follows: T0=48.5, T1=48.5, T2=59.5, and T3=60. The mean Fatigue HRQL total scores over time were as follows: T0=53.9, T1=50.8, T2=61.3, and T3=62.0.

In the multivariate analysis, there was no significant change from T0 to T1 for the Total SCD HRQL score. There was a significant increase of 11.8 points (p<0.01) in the Total SCD HRQL score at T2. The same pattern was seen for the Total Fatigue HRQL scores with no significant change from T0 to T1 and an increase of 7.9 points (p<0.01) in the score at T2. Those with higher steady state (T3) HRQL scores had higher HRQL scores during crisis. None of the remaining covariates, hospital site, age ,gender hydroxyurea use, and disease severity were associated with significant differences in HRQL scores over time.

In the multivariate analysis of the specific HRQL SCD domain scores, there was significant improvement in 8 of the 9 HRQL domains. The greatest improvement in scores (parameter estimates) were noted in the pain and hurt (16.9), pain impact (15.3), and pain management (13.4) domains, p<0.01. The only domain where significant improvement was not noted was the Communication I domain (3.4). There was significant improvement in scores in all of the specific Fatigue HRQL domains, the General Fatigue (9.3) and Sleep/Rest Fatigue (9.6), and Cognitive Fatigue domains (5.0), p<0.01.

This prospective study demonstrates that children with SCD have significantly lower HRQL at presentation of an acute VOC that improves by nearly 12 points one week post discharge. This is maintained at the steady state visit. The rate of change is not affected by hospital site, age, gender, hydroxyurea use, and disease severity. These findings provide the necessary data to tailor future interventions that aim to optimize HRQL for these patients.