Assessing the validity and reliability of the Malagasy version of Oral Impacts on Daily Performance (OIDP): a cross-sectional study

BACKGROUND Evaluating health needs includes measures of the impact of state of health on the quality of life. This entails evaluating the psychosocial aspects of health. To achieve this, several tools for measuring the quality of life related to oral health have been developed. However, it is vital to evaluate the psychometric properties of these tools so they can be used in a new context and on a new population. The purpose of this study was to evaluate the reliability and validity of the Malagasy version of a questionnaire for studying the impacts of oral-dental health on daily activities (Oral Impacts on Daily Performance), and analyse the interrelations between the scores obtained and the oral health indicators. METHOD A cross-sectional study was performed for the transcultural adaptation of the Oral Impacts on Daily Performance questionnaire forward translated and back-translated from English to Malagasy and from Malagasy to English, respectively. The psychometric characteristics of the Malagasy version of the Oral Impacts on Daily Performance were then evaluated in terms of internal reliability, test-retest, and construct, criteria and discriminant validity. Four hundred and six adults responded in face-to-face interviews to the Malagasy version of the Oral Impacts on Daily Performance questionnaire. RESULTS Nearly 74% of the participants indicated impacts of their oral health on their performance in their daily lives during the 6 months prior to the survey. The activities most affected were: "smiling", "eating" and "sleeping and relaxing". Cronbach's alpha was 0.87. The construct validity was demonstrated by a significant association between the Oral Impacts on Daily Performance scores and the subjective evaluation of oral health (p <0.001). Discriminant validity was demonstrated by the fact that the Oral Impacts on Daily Performance scores were significantly higher in subjects with more than ten missing teeth, compared to those with fewer than ten missing teeth (p < 0.001). CONCLUSION The Malagasy version of the Oral Impacts on Daily Performance index is a valid and reliable measure for use in Malagasy adults over 55 years old.