Zeitschrift für Schmerz und Linderung

Abstrakt

Evaluation Of The Brief Illness Perception Questionnaire In Sub-Acute And Chronic Low Back Pain Patients: Data Quality, Reliability And Validity

Løchting I, Garratt AM, Storheim K, Werner EL and Grotle M

Background

Illness perceptions have received increasing attention in the treatment of a range of illnesses and medical conditions, however, the instruments available have not been evaluated on sub-acute and chronic low back pain patients. This study aims to evaluate the Brief IPQ in the prevailing patient group. Methods

The Brief IPQ was administered to 90 patients attending care in Norway and evaluated for data quality, reliability and validity. The questionnaire was re-administered to 61 patients within a week for re-test purposes. The evaluation followed COSMIN recommendations for measurement properties.

Results

Item missing data ranged from 0% to 6.7%. Item-total correlation ranged from 0.12 to 0.67. Cronbach’s alpha was 0.72 for the Brief IPQ scale. Test-retest intra class correlation (ICC) values were 0.86 for the scale and ranged from 0.64 to 0.88 for the individual items. The standard error of measurement (SEM) for the Brief IPQ scale (0- 10) was 0.63 and the minimal detectable change (MDC) was 1.75. The MDC for single items (0-10) ranged from 3.16 to 4.40. Brief IPQ scale scores were approximately normally distributed and had small to moderate correlations with the reference scales supporting the hypotheses, however, the hypothesis were only partly supported on single item level.

Conclusions

The Brief IPQ can be applied as a concise instrument for assessing illness perceptions of patients with sub-acute and chronic low back pain. The Brief IPQ scale has evidence for reliability and validity however the evidence was less satisfactory at the item level.