Dr. Royce is Assistant Clinical Professor, Department of Epidemiology and Biostatistics, University of California, San Francisco (without salary). She currently works for the California Department of Health Care Services where she is Chief, Medical Quality Oversight Section of the Managed Care Quality and Monitoring Division. Before this position in Medi-Cal managed care, her career focused on tuberculosis (TB) control, from 1992-2008 as chief of the TB control branch, California Department of Public Health and then as an global TB consultant in 19 countries in Asia, Africa and Europe.

With the Cochrane HIV/AIDS Group, she led a systematic review on integration of tuberculosis and HIV services to inform the 2013 World Health Organization (WHO) consolidated guidelines on antiretroviral therapy. Dr. Royce was the lead consultant for the development of the WHO Treatment of TB guidelines. In her WHO guidelines work, she used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to rate the quality of evidence and strength of recommendations.

Dr. Royce also conducted a mixed methods study of barriers and facilitators of multidrug resistant TB case finding in Cambodia supported by a UCSF Pilot T2 (Bedside to Community) Translational Science grant. Guidelines for National Programmes.