The Lancashire Quality of Life Profile: modification and psychometric evaluation.

Background: Although widely used in Europe, the conceptual and psychometric qualities of the Lancashire Quality of Life Profile (LQoLP) have not been thoroughly examined. Four issues need attention: coverage, scale construction, systematic missing data, and psychometric properties.

Method: Concept mapping was used to examine the coverage, and exploratory factor analysis to examine the empirical scale structure of the LQoLP. Data of 518 long-term patients from ten different mental health care settings were used. Modifications to the LQoLP were proposed on the basis of these findings, and its psychometric properties were tested. Thirty-one respondents participated in a test-retest reliability study (T1-T2: 2 weeks).

Results: The modified LQoLP covers the quality of life-concept in a more comprehensive manner. Internal consistency, test-retest reliability and validity are good.

Conclusions: The modified version of the LQoLP now covers ten domains, paying specific attention to patients' definition of quality of life (autonomy, coping, self-worth). Domains are now based on factor analysis. The problem of systematic missing data is solved. Psychometric properties are good. Because of moderate alphas, two domains need further investigation.