Predictors of pain expectation among adult outpatients with sickle cell disease

Expectations about pain influence postoperative and cancer pain, but has not been studied among adults with sickle cell disease (SCD). We determined the predictors of pain expectation from current and past pain variables reported by outpatients with SCD. During a routine outpatient clinic visit, 218 adults (18-74 years; 61% female; 98% African American; 73% SS, 18% SC, and 9% other genotype) completed PAINReportIt, a computerized McGill Pain Questionnaire plus items for pain expectation and goals, satisfaction with pain level, pain endured without medication, pain relief with past treatments, tendency to tell/not tell others about pain, current, least and worst pain intensity (averaged), worst common pain intensity, and amount of time during the past 24 hours that pain intensity was greater than tolerable. The average pain intensity was 4.5±2.9. Pain was better than expected for 44%, the same as expected for 46%, and worse than expected for 10%. Based on this distribution, we used two binary logistic regressions, one for the probability of pain not worse than expected, and one for the probability of pain better than expected. The chance of a patient considering pain to be worse than expected was significantly associated with patient gender (Est = -1.09, Z = -1.99, p<.05) and pain intensity (Est = -0.47, Z = -3.5, p<.001). No predictor, however, had a significant association with the chance of a patient considering pain to be better than expected. Among adults with SCD whose pain is often unpredictable, pain goals, past pain experiences, time with intolerable pain, and satisfaction were not associated with pain expectation. Patients with more intense average pain and men were more likely to report their pain was worse than they expected. Additional qualitative research is needed to better clarify the concept of pain expectation among adults with SCD.