The problem of measuring change in individual health-related quality of life by postal questionnaire: use of the patient-generated index in a disabled population

Abstract

The Patient-generated Index (PGI) is a health-related quality of life (HRQoL) measure which asks respondents to nominate the areas of their lives which are most affected by their health condition, so that they can then rate the severity of the effects and weight their relative importance. It is unusual amongst such measures in that it is designed for postal administration. This study assessed the ability of the revised PGI to measure change in HRQoL in a population of 161 people who had previously been identified as having limiting long-term illness. A questionnaire, including a revised version of the PGI and the developmental version of the SF-36, was mailed at two time points (T1 and T2), 4.5 months apart. The PGI was subsequently assessed in terms of practicality, validity, reliability and responsiveness. At T1, 62% of those who felt that they still had a health problem affecting their life completed the PGI correctly. These people were significantly younger and had spent longer in education than the remaining 38%. Only 19 respondents completed the PGI correctly on both occasions, rendering reliability and responsiveness testing inconclusive. The value of the PGI is significantly diminished by the fact that many people cannot complete it correctly. Future development of the instrument is appraised in the context of related measurement methods.

Using the Patient Generated Index to Evaluate Response Shift Post-stroke

“…Many subjects in our study also expressed difficulty understanding what was meant by 'all other non-health areas', a problem found with other study populations [10,27]. Previous studies which administered the PGI through postal questionnaires reported response rates of 65% in a disabled population [10], 74% for patients with low back pain [9], and 77% for a group of arthritic patients [28].…”

“…Individualized measure of HRQL The PGI [8][9][10] was used to evaluate individualized HRQL and to provide a structure for asking subjects to express the areas important for their HRQL. There are three steps to completing this measure.…”

Systematic review and economic modelling of the effectiveness and cost-effectiveness of non-surgical treatments for women with stress urinary incontinence

“…However, it is unclear whether this association is due to the most relevant examples being selected from the prompt list, or due to respondents being unwilling or unable to think of their own examples because the prompt list is already comprehensive. 104 We correlated the mean PGI score with the mean EQ-5D scores. This correlation was, as expected, found to be positive and statistically significant.…”

Measuring quality of life in prosthetic practice

“…Some people have difficulty understanding the system of direct weighting, thus limiting their use as self completed questionnaires (e.g. Macduff and Russell 1998). Individualized measures are also dependent on respondents volunteering domains of QoL important to them.…”