Musculoskeletal pain illness perceptions: factor structure of the Illness Perceptions Questionnaire-Revised.
BACKGROUND
The Revised Illness Perceptions Questionnaire (IPQ-R) is commonly used to measure illness perceptions. We tested whether the structure of the IPQ-R was appropriate for use with primary care musculoskeletal pain patients.


METHODS
Confirmatory (C) and exploratory (E) factor analyses (FA) were used to test whether the structure of the IPQ-R was supported for patients with knee pain (n = 393), hand pain (n = 2113) and back pain (n = 1591). CFA was used to test whether the timeline acute/chronic, timeline cyclical, consequences, personal control, treatment control, illness coherence and emotional representation dimensions of the IPQ-R were distinct; EFA was used to explore potential structure for patients' views on the cause of their condition.


RESULTS
Goodness-of-fit indices for the CFA were below our criteria for good model fit. Removal of six items from the model improved model fit, but our criteria for good model fit was still not achieved. An interpretable factor solution could not be determined for the causal items on the questionnaire.


CONCLUSIONS
Our data show limited evidence that the seven dimensions of the IPQ-R are distinct. A clear structure for the causal items was not determined. Further work is needed to develop the IPQ-R for use with primary care musculoskeletal pain patients.
Arthritis Research UK Primary Care Centre, Primary Care Sciences, Keele University, Staffordshire, UK. e.nicholls@keele.ac.uk
Elaine E
EE
Nicholls
Susan
S
Hill
Nadine E
NE
Foster
D000293:Adolescent; D000328:Adult; D000368:Aged; D001294:Attitude to Health; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D059352:Musculoskeletal Pain / Q000523:psychology*; D011594:Psychometrics; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D055815:Young Adult