A large body of research has documented a relationship between higher nurse-to-patient staffing ratios and better patient outcomes. To date, most studies have not identified an ‘optimal’ nurse staffing ratio, which creates a challenge for determining appropriate staffing levels. If increasing nurse staffing always produces at least some improvement in the quality of care, how does one determine what staffing level is best? Analytical methods that fully leverage the large datasets compiled through electronic health records, human resources systems and other sources can be applied to advance research on the composition of nursing teams to improve quality of care. Linking these rapidly advancing analytical approaches that assess the outcomes and costs of nurse staffing strategies to data on the impact of nurse staffing on the long-term costs of patient care will further advance the capacity of hospital leaders to design cost-effective policies for workforce deployment.