Construct Validity and Responsiveness of the Rapid Assessment of Physical Activity in Adults Living With HIV

Kenneth S Noguchi; Kelly K O'Brien; Rachel L Aubry; Soo Chan Carusone; Lisa Avery; Patricia Solomon; Ivan Ilic; Zoran Pandovski; Mehdi Zobeiry; Ada Tang

doi:10.1016/j.arrct.2021.100164

Construct Validity and Responsiveness of the Rapid Assessment of Physical Activity in Adults Living With HIV

Arch Rehabil Res Clin Transl. 2021 Oct 24;3(4):100164. doi: 10.1016/j.arrct.2021.100164. eCollection 2021 Dec.

Authors

Kenneth S Noguchi¹, Kelly K O'Brien^{2

3

4}, Rachel L Aubry², Soo Chan Carusone^{5

6}, Lisa Avery^{7

8}, Patricia Solomon¹, Ivan Ilic⁹, Zoran Pandovski⁹, Mehdi Zobeiry⁹, Ada Tang¹

Affiliations

¹ School of Rehabilitation Science, McMaster University, Hamilton, Ontario.
² Department of Physical Therapy, University of Toronto, Toronto, Ontario.
³ Rehabilitation Sciences Institute, University of Toronto, Toronto, Ontario.
⁴ Institute of Health Policy, Management, and Evaluation, University of Toronto, Toronto, Ontario.
⁵ Casey House, Toronto, Ontario.
⁶ Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario.
⁷ University Health Network, Toronto, Ontario.
⁸ Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario.
⁹ Toronto Central Grosvenor Street YMCA, Toronto, Ontario, Canada.

Abstract

Objective: To evaluate the construct validity and responsiveness of the Rapid Assessment of Physical Activity (RAPA) for measuring physical activity (PA) in adults living with HIV.

Design: Secondary analysis of an interrupted time-series intervention study.

Setting: Community-based fitness facility in Toronto, Canada.

Participants: Sixty-seven adults (N=67) living with HIV (n=5 women; mean age, 51.8±11.6 years) with available baseline data to assess for construct validity of the RAPA, of which 50 (n=4 women; age, 53.2±11.4 years) had follow-up data to evaluate responsiveness.

Interventions: Two months of a community-based exercise intervention involving thrice weekly multicomponent exercises.

Main outcome measures: We used a single-item PA questionnaire as a convergent outcome to the RAPA, while peak oxygen consumption, general health status, and number of concurrent health conditions were divergent outcomes. We tested 11 a priori hypotheses (6 construct validity, 5 responsiveness) using Spearman ρ, Wilcoxon signed-rank tests, Cohen's d, standardized effect size (SES), and standardized response mean (SRM). We considered acceptable construct validity and responsiveness if >75% of hypotheses were confirmed.

Results: All of the hypotheses (100%) for construct validity were confirmed. The RAPA demonstrated moderate correlations with the single-item PA questionnaire (ρ=0.61), and negligible correlations with divergent outcome measures (ρ=0.08-0.21). Two of the 5 hypotheses (40.0%) for responsiveness were confirmed. RAPA scores were significantly greater after 2 months of training (P<.001) and demonstrated a small to moderate effect size (d=0.50, SES=0.47, SRM=0.48). There was a low correlation between change in RAPA scores and change in single-item PA questionnaire scores (ρ=0.48).

Conclusions: The RAPA demonstrated acceptable construct validity and poor responsiveness in adults living with HIV. Therefore, the RAPA can be used cross-sectionally but may be used in conjunction with other measures of PA for adults living with HIV.

Keywords: CBE, community-based exercise; Exercise; HIV; PA, physical activity; Psychometrics; RAPA, Rapid Assessment of Physical Activity; Rehabilitation.