The reproducibility of two task-specific functional capacity evaluation protocols for household waste collectors

The aim of this study was to assess the reproducibility (i.e., agreement and inter-rater reliability) of two task-specific functional capacity evaluation protocols meant to simulate the daily workload of collectors using either two-wheeled waste containers or bags. A within-subjects design was used to assess reproducibility in terms of agreement and reliability. Twenty-one household waste collectors were assessed twice with both task-specific protocols with a time interval of seven days. Agreement was assessed using the Standard Error of Measurement (SEM), and inter-rater reliability was assessed using the Intra-Class Correlation Coefficient (ICC). For the task-specific protocol for waste collection using two-wheeled containers, agreement was excellent (SEM=0.9 points; 0-340 scale; mean score 339), but inter-rater reliability was poor (ICC=0.22). For the task-specific protocol for bag collection, agreement was acceptable (SEM=53 s; continuous scale; mean time 779 s), and inter-rater reliability was good (ICC=0.79). Reproducibility of the task-specific protocol for bag collection is acceptable to good, while the task-specific protocol for waste collection using two-wheeled containers has an excellent agreement but a poor reliability. Although face and content validity have been covered within the development of both protocols, further studies should evaluate the construct and criterion-related validity of both task-specific protocols