Debate continues about the hierarchy of skilled roles in the nursing workforce. For example, should there be grades of qualified nurses other than registered nurses? Should all registered nurses be prepared to degree level? And to what extent should the nursing workforce comprise staff who are not qualified as nurses? Such questions raise critical issues about how different configurations of staff affect patient care outcomes and whether judgements can be made about their cost effectiveness. This Policy+ article refers to systematically reviewed, international evidence in considering the implications for UK nursing of the inclusion of a second-level qualified nurse in the skill mix of the nursing workforce.