Chagas disease is a neglected tropical disease that can progress to a chronic cardiac form, leading to functional impairment and reduced exercise tolerance. Assessing functional capacity in this population is essential for guiding rehabilitation strategies. The Duke Activity Status Index (DASI) is a questionnaire-based tool commonly used to estimate functional capacity, but its correlation with other objective and subjective functional measures in Chagas disease remains unclear.

To evaluate the correlation between the DASI and functional performance measures, including the Human Activity Profile (HAP), the Sit-to-Stand Test (STS), and handgrip dynamometry, in patients with Chagas disease.

A cross-sectional study was conducted with 50 patients diagnosed with Chagas disease (66±8 years) in an endemic area for Chagas disease. Participants completed the DASI and HAP questionnaires and underwent physical performance tests, including the STS (5-repetition, 10-repetition, 30-second, and 1-minute protocols) for lower limb strength and endurance, as well as handgrip dynamometry for overall muscle strength. Correlation analysis was performed using Pearson’s or Spearman’s correlation coefficients, depending on data distribution.

The mean DASI score was 25.3 ± 9.4. The DASI showed a significant correlation only with the maximum (r = 0.714; p < 0.001) and adjusted HAP scores (r = 0.635; p < 0.001), suggesting an association with self-reported physical activity levels. However, DASI did not correlate with the STS or handgrip strength, indicating that it may not reflect actual lower limb strength or endurance in patients with Chagas disease.

The DASI showed a strong correlation with self-reported physical activity levels but did not correlate with objective functional tests, suggesting it may not fully reflect the physical performance of patients with Chagas disease. These findings highlight the importance of combining subjective and objective measures for a more comprehensive assessment of functional capacity in this population.

These findings suggest that the DASI may not fully capture the functional performance of patients with Chagas disease, particularly regarding muscle strength and endurance. While the DASI correlates with subjective measures of activity levels, its lack of association with objective tests highlights the need for complementary functional assessments in clinical practice. Therefore, incorporating performance-based tests such as STS and handgrip strength alongside self-reported questionnaires may provide a more comprehensive evaluation for guiding rehabilitation programs in this population.