Reproducibility and validity of a specific Sapphire FCE test protocol for refuse collectors.

The job of refuse collector is characterised by heavy physical work demands.
Several studies showed an increased risk for musculoskeletal complaints which
can be responsible for a high sick leave rate. To optimalize the estimation of
work capacity, assessing physical work ability of refuse collectors with a
job-specific testprotocol could be essential.
Functional Capacity Evaluation (FCE) are safe performance-based assessments
striving to report objectively and systematically the current physical
work-ability of individuals with or without musculoskeletal complaints.
Work-related activities are assessed confom a standardized testprotocol. The
Sapphire Work Capacity Assessment System (Sapphire) is one of the FCE available
on the dutch market. Before to legitimately apply the Sapphire in any context
for any purpose, its clinimetric properties have to be evaluated. Clinimetric
properties reflect the measurement quality of a test or instrument, and are
divided under reproduciblity and validity.

The aim of this study is to evaluate the reproducibility and convergent
validity of a specific Sapphire testprotocol for refuse collectors.

A within-subject and between-raters design is used to assess the
reproducibility and validity of the Sapphire testprotocol. All subjects are
assessed twice on the Sapphire testprotocol for bags and two-wheeled containers
by two different raters. The time interval between both test moments is 3 (± 1)
days. To evaluate the relation between the Sapphire testprotocols and
self-report physical work ability (convergent validity), all subjects are asked
before the first test moment to answer three questions on their physical work
ability. A counterbalanced design for raters is used.

The risk in participating in the study is minimal: activities assessed through
an FCE are activities that occur in their jobs and in daily life. All
participants can withdraw at any moment from the study and the burden during
FCE assessment depends directly on the participant* own perception.
Furthermore, FCE are assessed by trained and certificated evaluators.