Reference Values for 7 Different Protocols of Simple Functional Tests: A Multicenter Study

Abstract

Objectives: To establish reference values and equations (ages 20-80y) for 7 simple functional tests based on a multicenter study.

Design: Cross-sectional data collection in 4 research centers across different regions of a continental dimension country.

Setting: Healthy subjects from general community were assessed in different research laboratories.

Participants: Data collection of 296 volunteer subjects (N=296; 45% men; aged 50±18y, forced expiratory volume in the first second 95±13% pred, body mass index 26.9±4.5 kg/m²) aged 20-80 years; representing both sexes; with the ability to understand and perform all proposed assessments; and with no severe and/or unstable condition that could limit functional assessments occurred simultaneously in all centers.

Interventions: Not applicable.

Main outcome measures: All participants randomly performed the following 7 functional tests twice: (1) the 4-meter gait speed test at usual walking speed; (2) the 4-meter gait speed test at maximal walking speed; (3) the Sit-to-Stand test performed with 5 repetitions; (4) the Sit-to-Stand test performed in 30 seconds; (5) the Sit-to-Stand test performed in 1 minute; (6) the Timed Up and Go test at usual speed; and (7) the Timed Up and Go test at maximal speed. Spirometry, quality of life, depression, anxiety, physical activity, and comorbidities were also assessed to better characterize the sample. The best performance of each test was used to propose reference values for men and women and reference equations for all.

Results: Participants similarly distributed by age groups from the 4 centers were included. All tests were correlated with age (0.34<r<0.53) and body mass index (0.24<r< 0.31; P<.05 for all). Reference values with limits of normality were provided by each 10-year age group and regression models identified reference equations for all tests. Reliability of the reference equations were confirmed in an independent sample.

Conclusions: Reference values and equations for 7 widely used simple functional tests were provided in this study and might help researchers and clinicians to identify and quantify functional impairments using easy-to-perform assessments.

Keywords: Exercise test; Physical fitness; Physical functional performance; Reference values; Rehabilitation; Reliability; Walking.