The impact of vaso-occlusive crises and disease severity on quality of life and productivity among patients with sickle cell disease in the US.

AIM: Sickle cell disease (SCD) is a lifelong blood disorder affecting approximately 100,000 individuals in the United States (US). A number of new treatments have recently become available to improve SCD clinical outcomes, but it is unclear how treatment innovations that reduce disease severity could affect patients' humanistic and economic outcomes. METHODS AND MATERIALS: To answer this question, an online survey of US adult residents with a self-reported SCD diagnosis was conducted. Humanistic outcomes based on health-related quality of life (HRQoL)) were assessed during and outside of vaso-occlusive crises (VOCs). Economic outcomes were measured by annual household income and whether the respondent received disability insurance. RESULTS: Among the 301 respondents completing the survey, average age was 34.4 years and 73.4% were female. Average HRQoL, measured using health utilities, were 0.311 (95% CI: 0.286, 0.337) during a VOC and 0.738 (0.720, 0.756) not during a VOC. The likelihood of claiming disability insurance was correlated with more frequent VOCs (0 VOCs: 12% vs. ≥4 VOCs: 47%, p = .002) and disease severity (Severity Class II: 16% vs. Severity Class III: 39%, p = .03). There was a weak relationship between VOC frequency and household income (0 VOCs: $47,488 vs. ≥4 VOCs: $34,569, p = .06) and no evidence of a relationship between disease severity class and income (Severity Class II: $42,443 vs. Severity Class III: $36,842, p = .29). CONCLUSION: In conclusion, disease severity, strongly predicted worse self-reported HRQoL, moderately predicted increased likelihood of collecting disability insurance, and weakly predicted lower household income levels.

Development of a Severity Classification System for Sickle Cell Disease.

PURPOSE: There is no well-accepted classification system of overall sickle cell disease (SCD) severity. We sought to develop a system that could be tested as a clinical outcome predictor. PATIENTS AND METHODS: Using validated methodology (RAND/UCLA modified Delphi panel), 10 multi-disciplinary expert clinicians collaboratively developed 180 simplified patient histories and rated each on multiple axes (estimated clinician follow-up frequency, risk of complications or death, quality of life, overall disease severity). Using ratings on overall disease severity, we developed a 3-level severity classification system ranging from Class I (least severe) to Class III (most severe). RESULTS: The system defines patients as Class I who are 8-40 years with no end organ damage, no chronic pain, and ≤4 unscheduled acute care visits due to vaso-occlusive crises (VOC) in the last year. Patients <8 or >40 years with no end organ damage, no chronic pain, and <2 unscheduled acute care visits are also considered Class I. Patients any age with ≥5 unscheduled acute care visits and/or with severe damage to bone, retina, heart, lung, kidney, or brain are classified as Class III (except patients ≥25 years with severe retinopathy, no chronic pain, and 0-1 unscheduled acute care visits, who are considered Class II). Patients not meeting these Class I or III definitions are classified as Class II. CONCLUSION: This system consolidates patient characteristics into homogenous groups with respect to disease state to support clinical decision-making. The system is consistent with existing literature that increased unscheduled acute care visits and organ damage translate into clinically significant patient morbidity. Studies to further validate this system are planned.

The relationship between frequency and severity of vaso-occlusive crises and health-related quality of life and work productivity in adults with sickle cell disease.

PURPOSE: Patients with sickle cell disease (SCD) may experience sickle cell-related pain crises, also referred to as vaso-occlusive crises (VOCs), which are a substantial cause of morbidity and mortality. The study explored how VOC frequency and severity impacts health-related quality of life (HRQoL) and work productivity. METHODS: Three hundred and three adults with SCD who completed an online survey were included in the analysis. Patients answered questions regarding their experience with SCD and VOCs, and completed the Adult Sickle Cell Quality of Life Measurement Information System (ASCQ-Me) and the Workplace Productivity and Activity Impairment: Specific Health Problem (WPAI:SHP). Differences in ASCQ-Me and WPAI:SHP domains were assessed according to VOC frequency and severity. RESULTS: Nearly half of the patient sample (47.2%) experienced ≥ 4 VOCs in the past 12 months. The most commonly reported barriers to receiving care for SCD included discrimination by or trouble trusting healthcare professionals (39.6%, 33.3%, respectively), limited access to treatment centers (38.9%), and difficulty affording services (29.4%). Patients with more frequent VOCs reported greater impacts on emotion, social functioning, stiffness, sleep and pain, and greater absenteeism, overall productivity loss, and activity impairment than patients with less frequent VOCs (P < 0.05). Significant impacts on HRQoL and work productivity were also observed when stratifying by VOC severity (P < 0.05 for all ASCQ-Me and WPAI domains, except for presenteeism). CONCLUSIONS: Results from the survey indicated that patients with SCD who had more frequent or severe VOCs experienced deficits in multiple domains of HRQoL and work productivity. Future research should examine the longitudinal relationship between these outcomes.