| The underlying structure of the proposed Self-Perceived Quality of Life (SPQL) construct was investigated. The scale for measuring the SPQL construct, consisting of three axes, subjective well-being, affective experiences, and fulfillment of needs, was developed and validated. The data was collected using online and mail surveys. A majority of participants were recruited by a California-based survey data collection company. The rest were recruited from Palo Alto, California based graduate schools. Participants received rewards in the form of Amazon.com gift certificates. A total of 137 normal adults, ages 20 to 83, who reside in the United States, participated in the study. The number of scale items was reduced through preliminary factor analyses. A confirmatory factor analysis identified higher order factors which, in turn, loaded onto a single higher hierarchy latent factor proposed to represent the SPQL construct. The demonstrated hierarchical structure of the SPQL construct supported the SPQL theoretical model. Content and face validities were established through peer review and a cognitive interview. Moderate or high Cronbach's A coefficients for the SPQL scales established the internal consistency. The criterion validity was established by showing that SPQL overall scores discriminated between groups which differ in their overall health. Moderate correlation coefficients between the SPQL scales, the Satisfaction With Life Scale, and the World Health Organization QOL-Bref questionnaire, demonstrated robust construct validity. Moderate to strong coefficients of stability between SPQL scale responses of the same 30 participants separated by 2 weeks demonstrated good test-retest reliability. The SPQL scales and factors have robust psychometric properties and are based on the integrated theory, which synthesized different approaches to the conceptualization and measurement of quality of life. This study offers a number of contributions to the field, including the comprehensive theory of SPQL and the scale, which allows measuring SPQL. |
