Development and validation of a condition-specific measure for chronic periodontitis: Oral health impact profile for chronic periodontitis.

AIM: The aim of this study was to develop and validate the first condition-specific tool to assess oral health-related quality of life (OHRQoL) impairment in association with chronic periodontitis and to use it as an outcome measure in clinical trials.

METHODS: Twenty-three potential items were developed using a combined method consisting of a literature review, semi-structured patient interviews (n = 20) and expert panel 1. Subsequently, item selection was carried out by means of qualitative content analysis and quantitative classical test theory (CTT) with 110 patients and expert panel 2. Consequently, 18 items were selected and included in the final oral health impact profile for chronic periodontitis (OHIP-CP) instrument. The validity and reliability of the OHIP-CP were then examined.

RESULTS: A total of 238 patients participated in the validation phase of OHIP-CP. The final 18-item questionnaire was shown to have a three-domain structure. The three components "pain and functional limitation", "psychological discomfort" and "psychological disability and social handicap" explained 49.9%, 9.9%, and 6.2% of the variance, respectively, together accounting for 66.1% of the variance. In addition, the OHIP-CP was shown to be valid in distinguishing patients with varying severity of chronic periodontitis. For the convergent validity, the reported impact of chronic periodontitis based on the OHIP-CP significantly correlated with the global oral health rating. All of its three domains were found to have good levels of internal consistency with Cronbach's alpha >.7, and excellent test-retest reliability.

CONCLUSION: The OHIP-CP is the first condition-specific OHRQoL instrument for patients with chronic periodontitis. This short, reliable and valid questionnaire may serve as a valuable tool in future clinical trials.