Data are from the National Sample Survey of Registered Nurses (NSSRN). Ordinary least-squares regression was used for the model, which included gender (male, female), age, race (white, nonwhite), marital status (married, divorced or widowed, never married), children at home (yes, no), foreign education (yes, no), education (diploma, associate’s degree, bachelor’s degree, master’s or doctorate degree), hours worked per week, years since graduation, polynomial of second degree and years since graduation, Metropolitan Statistical Area (MSA) (in MSA, not in MSA), state (51 categories), survey year (1988, 1992, 1996, 2000, 2004, 2008), work setting (hospital, ambulatory, other), clinical specialty (orthopedics, medical or surgical, neurology, newborn or pediatrics, chronic care, psychiatry, cardiology, other), job position (staff nurse, advanced clinical nurse, nurse anesthetist, education/research, senior academic, middle management, senior administration, other), and interaction terms of gender with work setting, clinical specialty, job position, and survey year. All continuous variables were mean centered. This model accounted for about half of the variance in salaries (R² = 0.46). The estimated average salary gap was $5148. Orthopedics was the only nonsignificant clinical specialty. Senior academic was the only nonsignificant job position. Survey weights were applied to make results nationally representative. Salary amounts reflect 2013 dollars and were normalized using the consumer price index. Error bars indicate 95% confidence intervals.
Corresponding Author: Ulrike Muench, PhD, RN, Department of Social and Behavioral Sciences, University of California, 3333 California St, San Francisco, CA 94118 (firstname.lastname@example.org).
Author Contributions: Dr Muench had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: All authors.
Acquisition, analysis, or interpretation of data: Muench, Sindelar, Buerhaus.
Drafting of the manuscript: All authors.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Muench, Busch.
Obtained funding: Muench.
Administrative, technical, or material support: Muench, Busch, Buerhaus.
Study supervision: Sindelar, Busch.
Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Buerhaus reported receiving payment for lectures from a variety of organizations, associations, universities, and groups; and being appointed chair of the National Health Care Workforce, which was established under the Affordable Care Act, but has not begun any work yet. No other disclosures were reported.
Funding/Support: This study was in part supported by a grant from Sigma Theta Tau, Delta Mu Chapter.
Role of the Funder/Sponsor: Sigma Theta Tau had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Additional Information: We dedicate this study to Donna Diers, PhD (Yale School of Nursing), who died during the early stages of this research.