Predictors of Pain in Sickle Cell Disease

Severe, disabling pain is the hallmark of sickle cell disease (SCD). SCD pain is associated with poor quality of life, early mortality, and high healthcare costs. Clinicians face great challenges in managing SCD pain because of the poor understanding of the etiology of chronic/persistent SCD pain and the absence of validated clinical predictive tools that can accurately identify individuals with SCD who are at risk of developing severe, persistent pain with associated physical and/or psychological disability. The overall objective of this study is to identify predictors of pain severity and pain-related outcomes in SCD using a prospective, longitudinal study design. This proposal is supported by the hypothesis that pain-specific psychological and sensory factors are strong, modifiable predictors of SCD pain severity and pain-related outcomes. The understanding of pain-specific psychological and sensory predictors of SCD pain outcomes is anticipated to have important implications for (1) identifying SCD patients who are at risk for severe pain outcomes, (2) informing preventive and therapeutic management of SCD pain, and (3) selecting patients for clinical trials of non-opioid interventions for SCD pain. The hypothesis will be tested by pursuing two specific aims: Aim 1) Determine psychological predictors of pain outcomes; and Aim 2) Ascertain the strength of pain distribution and sensitivity as predictors of pain outcomes. The researchers will use reliable and well validated pain-specific patient-reported outcome (PRO) questionnaires to evaluate the strength of psychological factors for predicting pain severity and other pain-related outcomes in the study cohort (Aim 1) and will use body mapping and quantitative sensory testing (QST) to examine sensory predictors of pain outcomes (Aim 2).

All participants must be between 15 and 40 years old and must be able to provide informed, written consent (for adults) or parental consent (for participants younger than 18 years).

Inclusion criteria

• Diagnosis of sickle cell disease (documentation of SS, SC, S beta + thalassemia, S beta + thalassemia) is required
• Participants must have had at least one sickle cell related pain episode that required treatment with opioids at home or in the hospital 12 months prior to recruitment
• Participants who are on chronic analgesics (NSAID, acetaminophen) or opioids should be on a stable dose for 4 weeks prior to recruitment.

Exclusion criteria

• Age less than 15 or greater than 40 years
• Participants lacking the cognitive or mental capacity to assent to and complete study procedures
• Pregnant females
• Participants with history of a stroke with ongoing physical impairment that prevents participation in study procedures.
• Participants with history of severe vaso-occlusive pain crisis resulting in either evaluation in an emergency department or admission to a hospital two weeks prior to study enrollment.
• Current or active infection
• Any condition that the principle investigator considers would preclude or bias participation in the study, such as (1) neuropathy from diabetes or other causes, (2) active avascular necrosis requiring treatment for pain