Epidemiological evaluation of short-form versions of the Child Perception Questionnaire.

The objective of the study was to compare the performance of four short-form versions of the Child Perceptions Questionnaire (CPQ(11-14)) with that of the long-form version in a random population sample of 12- and 13-yr-old children from New Zealand in order to determine which short-form version was the most valid. Children (n = 430, participation rate 74.1%) completed the 37-item CPQ(11-14). Two separate 8- and 16-item short-form versions were previously developed using (a) item impact and (b) regression methods. The four different short-form scales were compared with the full CPQ(11-14) on their construct validity. The children were examined for malocclusion (using the Dental Aesthetic Index) and for dental caries by a single examiner (L.F.P.). All short-form versions revealed substantial variability in overall oral health-related quality of life (OHRQoL). Cronbach's alpha ranged from 0.73 (Regression Short Form [RSF]-8) to 0.86 (RSF-16). For all short-form versions, mean scores were positively associated with self-rated oral health and overall wellbeing; associations with the latter were stronger. All short-form versions detected OHRQoL gradients, as hypothesized, across ascending categories of caries and malocclusion. These findings suggest that the short-form versions of the CPQ(11-14) all show acceptable properties, but that the 16-item versions perform better (and are essentially equivalent); however, the stronger theoretical underpinning of the item-impact-derived 16-item short-form version suggests that it shows the most promise.