J Head Trauma Rehabil Copyright c  2015 Wolters Kluwer Health, Inc. All rights reserved. The Relationship of Health Locus of Control and Health-Related Quality of Life in the Chronic Phase After Traumatic Brain Injury Janet E. Wielenga-Boiten, MD; Majanka H. Heijenbrok-Kal, PhD; Gerard M. Ribbers, MD, PhD Objective: To study health locus of control (HLC) after moderate to severe traumatic brain injury (TBI) compared with norm values and in relation to health-related quality of life (HR-QoL) over time. Setting: Three level-1 trauma centers. Participants: Individuals with moderate to severe TBI (N = 85). Design: Prospective cohort study. Main Measures: Multidimensional health locus of control scales including internal control (Internal-HLC), control attributed to physicians (Physician-HLC) or to chance (Chance-HLC) and sickness impact profile-68 including physical and psychosocial HR-QoL. Results: One to 3 years after TBI, Internal-HLC, and Chance-HLC significantly declined, whereas Physician-HLC remained stable. Total and psychosocial HR-QoL did not change over time, but physical HR-QoL improved. Three years after TBI, Internal-HLC (P < .001), and Physician-HLC (P < .001) were significantly lower and Chance-HLC (P < .001) significantly higher than norm values. Chance-HLC was independently related to total (β = .321, P < .001) and psychosocial HR-QoL (β = .258, P < .001), adjusted for baseline characteristics, functional, and cognitive outcome. Conclusions: After TBI, HLC may change over time and may be different from healthy adults. The external Chance-HLC orientation has a negative relationship with HR-QoL. Future research focused on the effect of rehabilitation programs for improving the balance in internal and external locus of control is needed. Key words: brain injuries, locus of control, quality of life, rehabilitation I N EUROPE, MORE THAN 1.5 MILLION persons with traumatic brain injury (TBI) are admitted to hos- pital each year. 1,2 The majority of those with moderate to severe TBI experience significant disability, includ- ing psychosocial, cognitive, emotional, and behavioral issues, even years postinjury. 3 Loss of consciousness, posttraumatic amnesia, and demographic variables are known predictors of outcome after TBI. Health locus of control (HLC) is a psychological factor that has also been studied as a predictor of outcome in chronic dis- ease. While HLC has been studied in TBI, additional detailed study of the relationship of HLC to long-term Author Affiliations: Rijndam Rehabilitation Center and Department of Rehabilitation Medicine, Erasmus MC, University Medical Center Rotterdam, the Netherlands. This study was financially supported by the Netherlands Organization for Health Research and Development (project no. 1435.0020). The authors declare no conflicts of interest. Corresponding Author: Majanka H. Heijenbrok-Kal, PhD, Rotterdam Neu- rorehabilitation Research-RoNeRes, Rijndam Rehabilitation Center and Eras- mus MC, Rotterdam, Westersingel 300, 3015 LJ Rotterdam, the Netherlands (mheijenbrok@rijndam.nl). DOI: 10.1097/HTR.0000000000000128 outcomes and to health-related quality of life (HR-QoL) is needed. Rotter introduced the construct of HLC in 1966, 4 to assess “the degree to which individuals believe that their health is controlled by internal (within the person) or external factors (outside the person).” Examples of ex- ternal factors include powerful others such as healthcare professionals and chance. 5,6 When HLC is attributed to healthcare professionals, individuals are more likely to believe that physicians control whether or not they are able to attain and maintain good health (ie, Physician- HLC). Chance-HLC is the extent to which persons per- ceive their health is controlled by chance factors (ie, fate or luck). Internal-HLC reflects the extent to which persons believe their health to be dependent on their own behavior. In those with acute or chronic illness or with symptoms of illness, relatively low internal HLC and high external HLC have been described in compar- ison with healthy individuals. 6 Uncontrollable stressful events may also reinforce the tendency of individuals to attribute control of their health to external factors. 7 Several studies have focused on HLC in individuals with TBI. If HLC is related to outcome after TBI, HLC could be a potential target in rehabilitation for those Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. 1