A gap approach to exploring quality of life in mental health.

Improving quality of life (QoL) is an important treatment outcome for the serious mentally ill. There is, however, a need for an instrument which both captures consumers own assessments and gives direct information for intervention. A useful approach is to define QoL as the gap between actual and ideal life circumstances, which is weighted by importance. In this paper we detail how we developed and evaluated a QoL instrument which follows this model. This instrument, the 'QoL-GAP', is based on self-appraised items within various life domains. For each item respondents firstly identify what they have (actual) and then what they would like (ideal). They then rate the item for its importance and make any comments. A weighted gap score for each item is subsequently derived from the ideal actual gap being weighted by the importance rating. This weighted gap score is then related to domain satisfaction ratings, while their average from each domain is related to overall satisfaction and well-being. We surveyed 120 individuals with a serious and enduring mental illness living in different types of residences, such as psychiatric hospitals, hostels, or their own homes, in a largely urban part of Queensland. Sixty-eight percent were males, and 92% had schizophrenia or related disorders. We found that our approach demonstrated good psychometric properties, and that the model-based predictions were borne out: weighted gap measures were consistently more strongly related to domain satisfaction than were the actual circumstances alone. While further work is being undertaken--in such matters as short-forms and further evaluation of the QoL-GAP in a longitudinal study--our results suggest that this 'gap' approach helps consumers state their own goals and give their opinions and so is particularly relevant for consumer-focused mental health delivery and research.