How Span of Control Is Defined and Measured: A Systematic Literature Review to Inform Healthcare Leaders

Abstract

Span of control (SOC) is most often defined as the number of employees directly reporting to a manager. If a manager’s SOC is too narrow or too wide, there may be variation in outcomes. SOC may influence decisions relating to organizational operations, workforce goals, and ultimately, patient outcomes. This study aimed to examine how SOC related concepts were defined and measured by health and non-health researchers, leading to the creation of a SOC nomological network that includes variables consistently and significantly correlated with SOC in more than one study. A systematic literature review of empirical SOC studies in all industries was completed using the PRISMA framework. Studies selected were from English peer-reviewed journals and dissertations in which SOC was operationally defined and measured with one or more other variables. Of the 620 studies that appeared in the initial search, 89 studies were eligible for the final review. Nearly all studies (93%, n = 83) measured SOC as a variable calculated as the number of direct reports per supervisor. SOC research in the health industry is relatively new, approximately 26% of studies reviewed came from health organizations. SOC correlates from 89 studies were classified as either organization-level or individual-level variables. Individual-level variables were further subdivided into manager-related and subordinate-related variables. In the studies included in this review, nine variables had consistent directionality with SOC: five organizational-level variables (lab test volume, safety accidents, gender diversity, perceived organizational support, and extent of project implementation) and four individual-level variables (manager’s satisfaction with supervision, managerial training, role conflict experienced by subordinates, and subordinate’s job performance). These nine correlates had positive directionality with SOC, except for manager’s satisfaction with supervision, which had a negative relationship with SOC. In studies that demonstrated significant and positive SOC correlates, researchers conceptualized managerial training and employee performance as antecedents of SOC, employee performance as both an antecedent and an outcome, and all the remaining correlates as outcomes of SOC. This systematic review demonstrated that wider SOC was linked to a variety of characteristics, both desirable (greater diversity, greater project completion, and higher employee performance) and undesirable (increased subordinate role conflict and greater manager dissatisfaction with supervision). However, the nine correlates in the nomological network might be of interest to health leaders who consider redesigning organizational structures to widen SOC. Leaders should also consider the antecedents, that is, the need to provide managerial training and the need to ensure sufficient subordinate performance prior to widening manager’s SOC. The Ottawa Hospital Span of Control (TOH-SOC) tool for clinical managers holds promise to assist nurse managers in judging the appropriateness of SOC. In sum, this systematic literature review is the first effort to examine how SOC is defined and measured in health and non-health organizations. This study systematizes and summarizes SOC research from different literature strands, as it evolved across time, to help future researchers design studies that strategically incorporate measures from the proposed SOC nomological network. The state of the SOC research does not yet allow to draw strong evidence-based recommendations to guide managerial decisions on how health organizations can be optimally structured for improved organizational, employee, and patient health outcomes.