Depression, sleep and pain affect instrumental activities of daily living through cognitive functioning in adults with sickle cell disease: A report from the Sickle Cell Disease Implementation Consortium.

Depression, disrupted sleep and pain are common comorbidities in sickle cell disease. We tested (1) if these comorbidities are associated with attention/executive functioning, processing speed and instrumental activities of daily living (IADLs), which describe complex skills that support independence, and (2) if cognitive symptoms mediate the relationship between comorbidities and IADLs. Participants (n = 2417) completed patient-reported outcome measures through the Sickle Cell Disease Implementation Consortium. Mean age of participants was 28 years and HbSS/Sβ⁰ genotypes were prevalent (73%). Comorbidities of depression, pain frequency and disrupted sleep were associated with processing speed and attention/executive functioning (all p < 0.01) when controlling for stroke and demographics. IADLs were associated with depression, pain, sleep, attention/executive functioning, income (<$25 000) (all p < 0.001) and genotype (p = 0.0025) after controlling for covariates. The indirect effects of attention/executive functioning and processing speed were both significant (p < 0.001) in mediation models that examined pathways between comorbidities and IADLs. Attention/executive functioning accounted for 17.5% of the relationship between depression and IADLs and sleep and IADLs. Processing speed explained 10% of the relationship between sleep and IADLs and 8% of the relationship between depression and IADLs. Managing comorbidities should be prioritized to mitigate cognitive symptoms and improve complex daily living skills.