Development and preliminary validation of the Exercise Fit Tool for adolescents undergoing cancer treatment in Hong Kong.

OBJECTIVE

This study aimed to develop and preliminarily validate the Exercise Fit Tool (EFT), a patient-reported self-assessment tool for adolescents undergoing cancer treatment in Hong Kong.

METHODS

A convenience sample of 158 adolescents aged 13-18 years who were undergoing cancer treatment and could communicate in Cantonese and read Chinese was recruited in Hong Kong. Instrument development followed the procedures recommended in AMEE Guide No. 87. Candidate items were generated from a literature review and focus groups with adolescents and healthcare professionals, refined by an expert panel, assessed for content validity, and revised through cognitive interviews. Pilot testing was conducted in 158 adolescents. Convergent validity was examined using pain scores and forced expiratory volume in 1 second (FEV1, % predicted), and criterion-related validity was evaluated by comparing EFT scores with physiotherapists' ratings. Test-retest reliability was assessed in 50 participants, and principal component analysis with Varimax rotation was performed.

RESULTS

The final 10-item EFT demonstrated satisfactory content validity, with I-CVIs ranging from 0.86 to 1.00, and good internal consistency (Cronbach's alpha = 0.92). The 2-week test-retest ICC was 0.82 (P < 0.001). EFT scores were negatively correlated with pain scores and positively correlated with FEV1 (% predicted), supporting convergent validity. The Kaiser-Meyer-Olkin measure was 0.87, and Bartlett's test of sphericity was significant (P < 0.001). Principal component analysis identified a two-component solution: cancer- and treatment-related influences on physical activity (7 items; Cronbach's alpha = 0.96; 55.7% of the rotated variance) and perceived physical activity exertion (3 items; Cronbach's alpha = 0.74; 20.6% of the rotated variance). Primary component loadings ranged from 0.74 to 0.93, and communalities ranged from 0.55 to 0.91. The two components explained 76.3% of the total variance.

CONCLUSIONS

The EFT demonstrated preliminary evidence of validity and reliability for adolescents undergoing cancer treatment in Hong Kong. Further evaluation of its latent structure and implementation in independent samples is required before wider clinical use.