title: Higher medical morbidity burden is associated with external locus of control.
abstract: OBJECTIVE
  To describe the association between an increasing number of coexisting conditions and locus of control (LOC), a psychological construct reflecting the degree to which one perceives circumstances to be controlled by personal actions (internal LOC) versus outside factors (external LOC) in older adults.
  
  
  METHODS
  Cross-sectional study using survey data from the North Carolina Established Population for Epidemiologic Studies of the Elderly (NC EPESE) data set.
  
  
  METHODS
  Community.
  
  
  METHODS
  Three thousand two hundred twelve community-dwelling adults aged 68 and older.
  
  
  METHODS
  Nine common medical conditions were assessed according to self-report. LOC was measured using a standard questionnaire. Analyses were adjusted for demographics, functional status (self-reported activities of daily living), cognition (Short Portable Mental Status Questionnaire), and depression score (Center for Epidemiologic Studies Depression Scale).
  
  
  RESULTS
  A higher number of chronic conditions was associated with external LOC (β = 0.37, P < .001). This relationship persisted after adjustment for age, race, sex, functional status, cognition, and depression (β = 0.17, P < .001). Most individual conditions were not associated with LOC, although vision impairment (P < .001) and arthritis (P = .02) were associated with more-internal LOC.
  
  
  CONCLUSIONS
  These results suggest that medically complex patients tend to exhibit a more-external LOC, meaning that they perceive little personal control over circumstances and environment. Clinicians should be aware of this tendency, because external LOC may impede an older adult's willingness to engage in the considerable task of managing multiple chronic conditions.
authors.affiliation: Duke University Medical Center, Durham, North Carolina 27710, USA. debra.henninger@gmail.com
authors.forename: Debra E
authors.initials: DE
authors.lastname: Henninger
authors.forename: Heather E
authors.initials: HE
authors.lastname: Whitson
authors.forename: Harvey J
authors.initials: HJ
authors.lastname: Cohen
authors.forename: Dan
authors.initials: D
authors.lastname: Ariely
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology*; D000223:Adaptation, Psychological; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease / Q000453:epidemiology* / Q000523:psychology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007389:Internal-External Control; D008297:Male; D009017:Morbidity / Q000639:trends; D009657:North Carolina / Q000453:epidemiology; D012189:Retrospective Studies