Developing an Instrument to Measure Physical Activity Related Self-Worth in Women: Rasch Analysis of the Women's Physical Activity Self-Worth Inventory (WPASWI)

Objectives: The objective of this study is to report on the development of an instrument to assess nonphysical

aspects of physical activity (PA)-related self-worth (SW).

Methods: Three hundred thirty five women (mean age ¼ 36.69  15.94 yrs, BMI ¼ 24.87  4.56)

completed the Women’s Physical Activity Self-Worth Inventory (WPASWI), General SW Scale, and a PA

Questionnaire. Rasch analysis was used to evaluate the WPASWI.

Results: Three PA-related SW subscales were identified: PA Knowledge (16 items), PA Emotional (13

items), and PA Social (8 items). Rasch analysis supported construct validity, and items demonstrated

acceptable internal consistency (Cronbach’s alpha ¼ 0.90, 0.87 and 0.72) and test-re-test reliability

(r ¼ 0.79, 0.70, 0.81). Women who reported regular PA participation had higher PA Knowledge, PA

Emotional, PA Social, and General SW than those who reported some or no PA (p < 0.01) and correlations

between Knowledge, Emotional, and Social SW subscales and General SW were 0.207, 0.130, and 0.220,

respectively. PA Knowledge and PA Emotional SW had stronger correlations with PA (r ¼ 0.344, 0.273,

respectively) than did General SW (r ¼ 0.133).

Conclusions: The WPASWI demonstrated good internal consistency, reliability, construct validity and

a stronger relationship with PA than a General SW instrument.