Measuring the impact of oral health on life quality in two national surveys - functionalist versus hermeneutic approaches.

Objectives: This study compares a functionalist (quantitative) versus a hermeneutic (qualitative) approach to assessing the impact of oral health on life quality in two United Kingdom national surveys.

Methods: The vehicles for this study were two Office for National Statistics' Omnibus Surveys completed in 1998 and 1999. In both studies a random probability sample of 3000 household addresses was selected from the British Postcode Address File (PAF). The data were collected by face-to-face interviews with respondents in their homes about how their oral health status affected their quality of life employing a qualitative, hermeneutic approach (1998) and a functionalist, quantitative approach using a battery of questions (1999).

Results: Irrespective of study design, in both studies it was apparent that the majority of the public perceived their oral health as affecting their life quality (P > 0.05). Likewise, both approaches identified that oral health affected life quality most frequently through physical aspects of oral health rather than social or psychological. However, using the hermeneutic approach, respondents were less likely to cite that their oral health affected specific aspects of their oral health compared to when a battery of questions were used (P < 0.01). Furthermore, socio-demographic variations in oral health-related quality of life were more apparent when a battery of questions were employed compared to an open-ended approach.

Conclusions: Different approaches to assessing oral health-related quality of life yield similar findings in terms of prevalence of oral health's impact and affected ways (domains). However, the different methods influenced the ability to identify socio-demographic disparities.