Objectives: The single-item question on self-rated health has been widely used in surveys. This study aims to explore which frames of reference are used by respondents when answering this question, to describe differences in the used frame of reference according to gender, educational background and age, and to determine whether subgroup differences can be explained by differences in prior health experiences.
Methods: Face-to-face interviews were conducted in a sample of 310 adults who were asked to rate their health using a single-item question with closed-ended answering categories and to explain the reasons for the rating they gave with open-ended probes. Different indicators of prior health experiences were taken into account.
Results: Physical health problems were the most utilized referents. However, participants also mentioned reasons that go beyond the physical dimension of health. Subgroup differences were found. Prior health experiences partly explained subgroup differences for some referents, but not for others.
Conclusions: Investigators using the single question on self-rated health for comparing health across different population groups should be aware that the meaning of the question varies across different socio-demographic groups.