The development and preliminary validation of a Preference-Based Stroke Index (PBSI).
BACKGROUND
Health-related quality of life (HRQL) is a key issue in disabling conditions like stroke. Unfortunately, HRQL is often difficult to quantify in a comprehensive measure that can be used in cost analyses. Preference-based HRQL measures meet this challenge. To date, there are no existing preference-based HRQL measure for stroke that could be used as an outcome in clinical and economic studies of stroke. The aim of this study was to develop the first stroke-specific health index, the Preference-based Stroke Index (PBSI).


METHODS
The PBSI includes 10 items; walking, climbing stairs, physical activities/sports, recreational activities, work, driving, speech, memory, coping and self-esteem. Each item has a 3-point response scale. Items known to be impacted by a stroke were selected. Scaling properties and preference-weights obtained from individuals with stroke and their caregivers were used to develop a cumulative score.


RESULTS
Compared to the EQ-5D, the PBSI showed no ceiling effect in a high-functioning stroke population. Moderately high correlations were found between the physical function (r = 0.78), vitality (r = 0.67), social functioning (r = 0.64) scales of the SF-36 and the PBSI. The lowest correlation was with the role emotional scale of the SF-36 (r = 0.32). Our results indicated that the PBSI can differentiate patients by severity of stroke (p < 0.05) and level of functional independence (p < 0.0001).


CONCLUSIONS
Content validity and preliminary evidence of construct validity has been demonstrated. Further work is needed to develop a multiattribute utility function to gather information on psychometric properties of the PBSI.
Poissant
Lise
L
McGill University, Health Informatics Research Group, 1140 Pine Ave West, Montreal, Quebec, H3A 1A3, Canada. lise.poissant@mcgill.ca
Mayo
Nancy E
NE
Wood-Dauphinee
Sharon
S
Clarke
Ann E
AE
D000368:Aged; D000369:Aged, 80 and over; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D017060:Patient Satisfaction / Q000706:statistics & numerical data; D010865:Pilot Projects; D011594:Psychometrics / Q000379:methods*; D011788:Quality of Life; D012720:Severity of Illness Index; D020521:Stroke / Q000145:classification / Q000503:physiopathology / Q000523:psychology; D011795:Surveys and Questionnaires