Purpose: To review published studies regarding the use, feasibility and psychometric performance of the schedule for the evaluation of individual quality of life-direct weighting (SEIQoL-DW) in clinical research.
Methods: Systematic literature review. Studies using the SEIQoL-DW were included if they were published in English and employed a quantitative design. A pre-defined checklist was used to analyse the reported results.
Results: Thirty-nine relevant articles were identified. The SEIQoL-DW has been included in studies relating to a variety of populations, including those who are severely ill. The results of convergent and discriminant validity support our hypotheses in which SEIQoL-DW was expected to correlate moderately to high with measures of global QoL, life satisfaction and mental health and weakly with measures of functional status and health.
Conclusion: The SEIQoL-DW appears to be a feasible and valid instrument. The lack of association between the Index score and health, functional status, demographic and clinical parameters may be explained by the instrument's focus on global QoL and by that of the idiographic measurement approach reflecting the capacity of a patient to value domains other than health in life, despite having health problems. Nevertheless, continued psychometric evaluation in large populations with a longitudinal design is recommended.