Background:

To determine the number of nurses who are supervised by a charge nurse in the Nursing Units of Aragonese general public hospitals and to analyze how this affects the organizational behaviors of nurses and the quality of the relationships established with the charge nurses.

Methods:

Cross-sectional study carried out in nine public hospitals. Validated questionnaires were used to assess the working behavior of nurses and the quality of their relationships with charge nurses, and the charge nurse's relationship with their immediate superior and nursing staff. We analyzed whether there was an association between these variables and the number of nurses per unit.

Results:

The study included 2,541 nurses and 192 supervisors. The mean span of control was 29 (SD = 22.4). Statistically significant differences were observed with respect to empowerment (p<0.001), satisfaction (p = 0.027), perceived organizational support (p<0.001) and the quality of the nurse's relationships with the supervisor (p<0.001) and the supervisor with her immediate superior (p<0.001), obtaining lower scores as the span of control increased. No significant associations were observed with respect to turnover intention, organizational citizenship behavior and organizational commitment.

Conclusions:

The span of control is related to the perception of nurses' organizational behaviors and with the quality of interpersonal relationships with the charge nurse, indicating a need to adjust the span of of control per unit in order to improve the quality of the management of the units.