Adaptation and Evaluation of the Active Australia Survey for Internet-Based Self-Administration

Purpose Evaluate the reliability and validity of a self-reported moderate-to-vigorous physical activity (MVPA) instrument administered by telephone and Internet.

Methods The Active Australia Survey (AAS), administered nationally in Australia by telephone (T), was adapted into two forms for Internet self-administration: survey questions only (I-Text) and with videos demonstrating intensity (I-Video). Data were collected from 158 adults (20-69 years, 61% female) randomized to T (n=56), I-Text (n=51), or I-Video (n=51). Participants wore an Actigraph and completed a logbook for study days 1-7. On days 8 and 11 participants answered the AAS. Test-retest reliability was assessed using intraclass correlation coefficients (ICC). Convergent validity was assessed using Spearman correlations relating responses to the AAS with Actigraph+logbook data.

Results Strong test-retest reliability was observed for walking, vigorous-intensity, and total MVPA in the I-Text [ICC=0.69-0.88], I-Video [ICC=0.66-0.79], and T [ICC=0.69-0.92] groups. All groups demonstrated moderate reliability for self-reported moderate-intensity activity [ICC=0.43-0.54]. All p-values<0.001. For total MVPA, the correlations between the AAS and Actigraph+logbook were rho=0.47 for the I-Text group, rho=0.57 for the I-Video group, and rho=0.65 for the T group. For vigorous-intensity activity, the correlations between AAS and Actigraph+logbook were rho=0.52 for the I-Text group, rho=0.57 for the I-Video group, and rho=0.65 for the T group. For walking+moderate-intensity activity, the correlation between the two measures was highest for the I-Video group (rho=0.46). All p-values<0.05.

Conclusions Both Internet versions of the AAS had similar test-retest reliability and convergent validity when compared to the standard telephone interview. This supports further exploration of Internet-based strategies for surveillance.