Background

This study assessed the validity of the International Physical Activity Questionnaire ? Short Form (IPAQ-sf) in people post COVID-19.

Methods

PA was assessed with both the IPAQ-sf and inertial systems, worn on the low back for 7 days; ?2 weekdays with ?8-hour records were accepted. Cut-offs were used to categorise participants into low-, moderately- and highly-active (IPAQ-sf: <600, 600-2999, ?3000 MET-min/week; inertial systems: <7500, 7500-9999, and ?10000 steps/day).

Validity was assessed with Spearman?s correlations (?) between the IPAQ-sf (METs-min/week, time in vigorous [VPA], moderate PA [MPA], walking time/week, and sedentary time/day) and inertial systems (VPA, MPA, and step-count/week; sedentary time/day) for continuous variables; polychoric correlations, weighted Cohen?s k, sensitivity, and specificity (95%CI) for categories.

Results

288 assessments of people post COVID-19 (52%men;55±15years) were included.

All outcomes had significant weak-to-moderate correlations (0.171<??0.371, p<0.001).

Categories presented significantly moderate correlation (r=0.486, p<0.001) although weak agreement (k=0.129, p<0.001). The low-active was highly sensitive (0.94 95%CI[0.84,0.99]) but low specific (0.22 95%CI[0.17,0.28]), while both the moderately and the highly-active were low sensitive (0.10 95%CI[0.06,0.16] and 0.23 95%CI[0.14,0.35]) but highly specific (0.88 95%CI[0.80,0.93] and 0.97 95%CI[0.94,0.99]).

Conclusions

The IPAQ presents a weak-to-moderate correlation and agreement with inertial systems. Furthermore, it identifies mostly low-active people and discriminates moderately- or highly-active participants poorly. Thus, its results should be taken with caution.