Validation of the human activity profile in the HIV-Positive population using indirect calorimetry

Abstract

Objective(s): To determine if the HAP is a valid measure of physical activity level for the HIV-Positive population. Design: Validation using VO2max as the "gold standard" to compare HAP scores resulting from the Maximal Activity Score (MAS) and the Adjusted Activity Score (AAS). Setting: Clinical laboratory Participants: Twenty-six HN-positive participants (23 male, 3 female; age 45.96±9.28 years) receiving HAART. Intervention: Participants completed the HAP and the exercise test on the same day. Maximal oxygen uptake was determined using standard indirect calorimetry techniques. Responses to the HAP resulted in two scores: the maximal activity score (MAS: maximal activity that is still being performed) and the adjusted activity score (AAS: MAS minus the number of activities that the subject can no longer perform). Correlations between AAS, MAS and VO2 max were generated. Main Outcome: MAS, AAS, and VO2max values. VO2max values were assessed using indirect Calorimetry. Results: Mean VO2max was 37.73 ± 6.95 ml O2kg-lmin-l. The mean MAS and AAS scores were 86.5 ± 7.6 and 75.7 ± 19.2, respectively. The VO2max was poorly correlated with MAS and AAS at p =0.31 and p =0.32, respectively. The poor correlations were likely due to the fact that the mean VO2max of the subjects in the present study exceeded 10 METS, the design limitations of the HAP. Conclusions: Based on the validation criteria used in the present study, the HAP is not a valid indicator of physical activity capacity for HIV -positive patients on HAART. Further study is needed to find a more accurate instrument to estimate physical activity capacity for this population.