title: Perceived control is a concurrent predictor of activity limitations in patients with chronic idiopathic axonal polyneuropathy.
abstract: OBJECTIVE
  To investigate (1) whether control perceptions (person's perception of ease or difficulty of performing behavior) and emotions contribute to activity limitations and if so (2) whether these variables mediate the relation between impairment and activity limitations in patients with chronic idiopathic axonal polyneuropathy (CIAP).
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Outpatient clinics of a university medical center.
  
  
  METHODS
  Fifty-six patients diagnosed with CIAP.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Control perceptions about performing activities (questionnaire based on the theory of planned behavior), emotions (Hospital Anxiety and Depression Scale), activity limitations (performance: Shuttle Walk Test [SWT]; self-report: Medical Outcomes Study 36-Item Short-Form Health Survey [SF-36] physical functioning subscale, self-reported ability to walk), and physical impairments (muscle strength, sensory function).
  
  
  RESULTS
  Control perceptions significantly (P<.01) correlated with all measures of activity limitations (r range, .58-.69). Hierarchical multiple regression analyses showed that perceived control explained 9% of the variance in the SWT (beta=.34, P<.01), 12% in the SF-36 (beta=.40, P<.01), and 24% in ability to walk (beta=.54, P<.01). In all measures of activity limitations, perceived control significantly mediated the effect of impairment.
  
  
  CONCLUSIONS
  Perceived control explained and mediated variance in activity limitations, whereas emotions did not. This suggests that increasing patients' perceptions of control might enhance performance of activities, even without changes in impairment.
authors.affiliation: Department of Neurology and Neurosurgery, Rudolf Magnus Institute of Neuroscience, Sections of Rehabilitation Medicine, University Medical Centre Utrecht, Utrecht, The Netherlands. c.schroeder@umcutrecht.nl
authors.forename: Carin
authors.initials: C
authors.lastname: Schröder
authors.forename: Marie
authors.initials: M
authors.lastname: Johnston
authors.forename: Laurien
authors.initials: L
authors.lastname: Teunissen
authors.forename: Nicolette
authors.initials: N
authors.lastname: Notermans
authors.forename: Paul
authors.initials: P
authors.lastname: Helders
authors.forename: Nico
authors.initials: N
authors.lastname: van Meeteren
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology*; D000368:Aged; D000704:Analysis of Variance; D001007:Anxiety / Q000209:etiology; D001294:Attitude to Health; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D003863:Depression / Q000209:etiology; D004644:Emotions; D005080:Exercise Test; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D033182:Intention; D007389:Internal-External Control; D008297:Male; D018908:Muscle Weakness / Q000209:etiology; D009426:Netherlands; D010146:Pain / Q000209:etiology; D011115:Polyneuropathies / Q000150:complications / Q000503:physiopathology* / Q000523:psychology*; D011237:Predictive Value of Tests; D011582:Psychological Theory; D012044:Regression Analysis; D020377:Self Efficacy; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D016138:Walking / Q000523:psychology