Funding for this research was provided by:
National Institute of Arthritis and Musculoskeletal and Skin Diseases (P50AR063043)
Office of Research on Women's Health (P50AR063043)
VA Career Development Award (K IK2 CX000549)
Received: 2 August 2017
Accepted: 20 November 2017
First Online: 4 December 2017
Ethics approval and consent to participate
: The study protocol was approved by the University of California San Francisco Institutional Review Board (Study #:12–09348) and Kaiser Permanente Northern California Institutional Review Board. Written informed consent to participate in the study was provided by all participants.
: Not applicable.
: The authors WBK, NP, EAP, AG, ALS, RKL, BF, SSW and NEL declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.