The Global Person Generated Index

The entry briefly describes the value of individualized quality of life measures and the philosophy behind them and outlines the main measures in this field. It then focuses on the Patient Generated Index (PGI) (Ruta et al., 1994) and explains its purpose and methodology. Three different forms of administration are explored and its use in a variety of healthcare settings is described. Finally, its psychometric properties are summarized. The Global Person Generated Index (GPGI) (Ruta et al., 2004a) is then introduced, which is an open-ended measure with a simple method of administration, appropriate for use in developing countries. The piloting and administration of the GPGI in three developing country settings is described in detail to illustrate the challenges of measuring quality of life in these contexts. The validation process is described, focusing particularly on the innovative technique of qualitative validation, which used semi-structured interviews collected on the same occasion to assess the accuracy with which the measure captured the respondent’s world view. Some response errors were identified, which required additional administrator training, and the value of a brief accompanying interview are discussed. The measure’s advantages are summarized, namely that is flexible and person-centered, relatively quick to administer, generates new information, works across cultures, and provides a direct measure of the gap theory of quality of life (Calman, 1984). The entry concludes that the common criticism of individualized measures that respondents are not rating the same dimensions evaporates when we consider that respondents are rating the results of their judgments of what is important to quality of life: these judgments are directly comparable (Parducci, 1995, p. 29). Therefore they provide a valid measure of people’s perceptions of the quality of their life as a whole across time.