Development of Needs-Based Quality of Life Instruments

Abstract

The methods employed in the development of needs-based quality of life (QoL) instruments have evolved with time as advances have been made in the field of psychometrics and as experience has grown. This paper illustrates the current instrument development methodology with reference to three needs-based QoL measures recently developed for use in dermatology: the Quality of Life Index for Atopic Dermatitis (QoLIAD); the Psoriasis Index of Quality of Life (PSORIQoL); and the Parents' Index of Quality of Life-Atopic Dermatitis (PIQoL-AD).

The development and validation of a new coeliac disease quality of life survey (CD‐QOL)

“…All subjects were told that the purpose of the focus group was to get a better idea of how coeliac disease affected their 'activities, capabilities, thoughts and feelings'. Open-ended questions ('scripted probes') were asked following the 'needs-based' model, 9,12 where questions relate to perceptions and concerns relating to the impact of the disease rather than to specific symptoms or functional limitations. Specific domains of interest were determined a priori based on expert opinion.…”

“…For the BSI, this included low (<48), medium (48-60) or high (>60) psychological distress. For daily abdominal pain, this included low (<10), medium (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) or high (>25) abdominal pain. For each of these measures, the mean CD-QOL of subjects in each group (low, medium, and high) was compared.…”

Willingness-to-pay stated preferences for 8 health-related quality-of-life domains in psoriasis: A pilot study

“…9 Needs-based instruments have robust psychometric properties, are easy for respondents to understand, are easy to administer, and are beneficial in their ability to detect real change in QOL when effective treatment is initiated. 6 Although these tools provide an overall measure of impact on HRQOL, and each instrument has particular strengths, they do not capture data that may be objectified and used in future studies. The willingness-to-pay (WTP) method uses US dollars as a proxy for strength of preference, allowing future work to be compared with this standardized metric.…”

“…4,5 Psoriasis-specific instruments have also been developed such as the Psoriatic Arthritis Quality of Life Instrument, a 20-item questionnaire that measures HRQOL in patients with psoriasis and summarizes impact from skin disease. 6 The Psoriasis Index of Quality of Life, a 25-item measure specific to psoriasis, has also been developed using a needsbased QOL model adopted for the Psoriatic Arthritis Quality of Life Instrument. 6 The Psoriasis Disability Index is a 15-item questionnaire that measures daily activities, work/school, relationships, leisure, and treatment effects based on the previous month.…”

“…6 The Psoriasis Index of Quality of Life, a 25-item measure specific to psoriasis, has also been developed using a needsbased QOL model adopted for the Psoriatic Arthritis Quality of Life Instrument. 6 The Psoriasis Disability Index is a 15-item questionnaire that measures daily activities, work/school, relationships, leisure, and treatment effects based on the previous month. 7 The Psoriasis Life Stress Inventory is a 15-item instrument designed to measure psoriasis-related stress associated with cosmetic disfigurement and social stigma, symptoms of disease, and treatment effects and puts more emphasis on psychological aspects of disease compared with the Psoriasis Disability Index.…”