Sickle Pain-Related Impact (SPiRIt): A Prospective Study of Impact of Chronic Pain in Sickle Cell Disease

Objective: (1) To compare the pain phenotype and pain-related patient-reported outcomes (PROs) between sub-phenotypes of chronic pain (CP), i.e., high-impact chronic pain (HICP) and mild-moderate chronic pain (MMCP) in adolescents and young adults with sickle cell disease (SCD) and CP. (2) Identify factors associated with higher odds of HICP in adolescents and young adults with SCD and CP.

Methods: This study enrolled adolescents and young adults aged 16- 40 with SCD from: 1) SCD comprehensive clinics at a large Southeastern academic center, and 2) online through community engagement via dissemination strategies of local and national SCD organizations and online communities for individuals with SCD. Dissemination strategies included newsletters, listservs, social media platforms (Facebook, Instagram, etc.), and other community engagement methods. Participants who completed the study were sent a study flyer which they could share with other individuals in their network or with their family/friends. Participants were included if they 1) had SCD, 2) met frequency criteria for SCD CP, which was based on the AAPT criteria for CP in SCD i.e., pain on most days of the month for the past 6 months, 3) were 16 to 40 years of age, 4) were English speaking, and 5) lived in the United States. The study team confirmed eligibility for potential participants who completed the screening form online, and eligible participants were then sent the informed consent form and surveys. Participants who could not be contacted by phone to confirm eligibility were not included in the study. For online consent and enrollment, several strategies were put into place to prevent bots and fraudulent survey responses to maximize data validity. Participants reported demographic, clinical, pain, pain related PROs, and psychological characteristics at baseline.

Results: Baseline study enrollment was from October 2022 to March 2023. During this period, we enrolled 90 participants. We enrolled 16 participants from SCD clinics and 74 participants via online recruitment approaches. The mean age of participants was 29.38 (SD=7.41) years and 81% self-identified as female. Seventy one percent had Hemoglobin SS or a similarly severe genotype, almost half (47.8%) reported avascular necrosis, 77.8% reported being prescribed disease modifying therapies or blood transfusions, and 81.1% reported taking medications for pain.

We found that 71% (n= 64) of the cohort met criteria for HICP. Those with HICP were older (mean age 30.36 (SD=6.91) vs mean age 26.96 (SD=8.18) years, p= 0.048). There were no other differences in demographic and clinical characteristics between HICP and MMCP groups. Individuals with HICP had higher scores for pain intensity, greater number of pain locations, higher neuropathic and nociceptive pain quality scores, higher pain interference, and higher pain impact. They also reported higher pain catastrophizing, greater fear of movement, lower self-efficacy for managing symptoms, and lower chronic pain acceptance. As compared to individuals with MMCP, individuals with HICP experienced poorer physical, social, and emotional function, and greater sleep disturbance.

We investigated predictors of HICP in univariable and multivariable logistic regression models. After adjusting for age, sex, education, and pain intensity, we found that pain catastrophizing (OR [95% CI] = 1.05 [1.01,1.1]) was associated with higher odds of HICP. We also found that self-efficacy for managing symptoms (OR [95% CI] = 0.91 [0.84,0.98]) and chronic pain acceptance (OR [95% CI] = 0.76 [0.59,0.96]) were associated with lower odds of HICP.

Conclusions: Among individuals with SCD and CP, those with HICP experienced greater pain burden and poorer outcomes. Pain catastrophizing is associated with increased odds of HICP, and self-efficacy and chronic pain acceptance are associated with lower odds of HICP.