The construct validity of the illness cognition questionnaire: the robustness of the three-factor structure across patients with chronic pain and chronic fatigue.
BACKGROUND
The Illness Cognition Questionnaire (ICQ; Evers et al., J Consult Clin Psychol, 69:1026-1036, 2001) assesses three ways of cognitively evaluating the stressful and aversive character of a chronic illness: helplessness, acceptance, and perceived benefits.


OBJECTIVE
The purpose of this study was to evaluate the construct validity of the ICQ in individuals with chronic pain and patients with chronic fatigue.


METHODS
The ICQ was administered to 821 individuals with chronic pain and 295 patients with chronic fatigue. Confirmatory factor analyses were performed to assess the hypothesized three-factor structure, containing the factors "helplessness," "acceptance," and "perceived benefits." A multigroup analysis was performed to investigate the stability of the factor structure in both groups.


RESULTS
Results confirmed the three-factor structure in the two samples. The factor structure was invariant across individuals with chronic pain and chronic fatigue.


CONCLUSIONS
As the three-factor structure provided a good fit in both groups, we confirm the usefulness of the subscale scores in research and clinical practice.
Lauwerier
Emelien
E
Department of Experimental-Clinical and Health Psychology, Ghent University, Henri Dunantlaan 2, 9000 Ghent, Belgium.
Crombez
Geert
G
Van Damme
Stefaan
S
Goubert
Liesbet
L
Vogelaers
Dirk
D
Evers
Andrea W M
AW
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D003071:Cognition; D005163:Factor Analysis, Statistical; D005221:Fatigue / Q000523:psychology*; D005260:Female; D006380:Helplessness, Learned; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000523:psychology*; D058748:Pain Perception; D010342:Patient Acceptance of Health Care / Q000523:psychology* / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires / Q000592:standards; D055815:Young Adult