The Mind-Body Study: study design and reproducibility and interrelationships of psychosocial factors in the Nurses' Health Study II.

Purpose: Associations between psychosocial factors and biomarkers are increasingly investigated in studies of cancer incidence and mortality. Documenting optimal data/biospecimen collection protocols and scale properties are fundamental for elucidating the impact of psychosocial factors on biologic systems and ultimately cancer development/progression.

Methods: Between 2013 and 2014, 233 Nurses' Health Study II women (mean age: 60.6) participated in the Mind-Body Study. Participants completed a detailed online psychosocial assessment and provided hair, toenail, timed saliva over 1 day, urine and fasting blood twice, 1 year apart. Additionally, two separate microbiome collections for stool and saliva were conducted between the psychosocial assessments. We assessed correlations between various psychosocial measures and evaluated their 1-year reproducibility using intraclass correlations (ICC).

Results: Compliance with the protocols was high among participants. Psychosocial measures showed moderate-to-high reproducibility over 1 year (ICCs = 0.51-0.81). There was clear clustering of psychosocial factors according to whether they were querying positive (e.g., optimism, mastery, mindfulness) or negative (e.g., anxiety, depression, discrimination) emotion-related or social constructs.

Conclusion: Results suggest feasibility for self-administered collection of various biospecimens and moderate-to-high reproducibility of psychosocial factors. The Mind-Body Study provides a unique resource for assessing inter-relationships between psychosocial factors and biological processes linked with long-term health outcomes, including carcinogenesis.