A Simple Assessment Method: Quick Exposure Check (QEC) has been Updated; Additional Validation Studies Released

If you are looking for a ten-minute evaluation method that can be used in a variety of work settings to assess task exposure to musculoskeletal disorder risk factors, the revised Quick Exposure Check (QEC) survey may be your ticket. This tool, created by David, Woods, Li and Buckle provides a weighted score that indicates relative risk of a body region, task, or risk factor. Further, the weighted score can be used to show pre/post intervention impact.

The QEC was introduced in the late 1990’s and recently augmented by new epidemiologic evidence and user feedback. It requires both examiner and worker participation in the evaluation of physical and psychosocial risk factors.

Presented in a recent study as a one page form, The QEC is a compact analysis method that has shown inter/intra-examiner reliability and select validity.

QEC Survey Development

The survey was initially developed from 1996 to 1998, following a series of steps consisting of:

• Literature Review – Physical and psychosocial risk factors related to WMSDs were identified by examining epidemiological research and evaluating methods used to identify physical work concerns.
• Practitioner Input – 93 occupational safety and health (OSH) professionals provided their perspective relative to current assessment tools and the design/content of an ideal survey. Opinions were sharpened within focus groups.
• Survey Verbiage and Design – Verbal assessments were conducted by eight OSH professionals while viewing video of three simulated tasks. This process identified preferred terminology and evaluation structure.
• Reliability Testing – Inter-examiner and intra-examiner consistency was established by having practitioners evaluate 18 videotaped tasks. Body region exposure score agreement ranged from 64.7% to 80.2% and 66.7% to 76.7% for inter-observer and intra-observer evaluations, respectively. This is considered fair to moderate.
• Validity Testing – Acceptable percent agreement occurred between SIMI 3D computerized motion analysis and the QEC scores of 18 OSH professionals in assessment of four videotaped tasks (72.3% to 87.5%). Further, percent agreement occurred between the QEC scores of six OSH professionals and expert analysis of 59 videotaped tasks (54.2% to 91.5%).

During 2000-2003, the QEC was refined through:

• Literature review – Recent research was evaluated to ensure currently identified risk factors were appropriately reflected in the QEC.
• Practitioner Input – The opinions of seven QEC users were gathered through interviews. A group of eight OSH professionals assessed five manual tasks using the QEC to provide feedback relative to survey content and practitioner guidance.
• Form Design – A team assessed the design, verbiage, and scoring layout.
• Trial Use – Following use of the revised QEC to evaluate a task, 10 OSH professionals offered feedback regarding usability.
• Graphic Design – A graphic designer improved the survey format which was reviewed by 19 professionals.
• Reliability Testing – After being trained in use of the QEC, six evaluators observed and scored three tasks. Inter-examiner score consistency was assessed and found to be improved over Phase 1 reliability testing.
• Validity Testing – Seven practitioners and two study team members evaluated five tasks at six worksites. Percent agreement of the survey score between each evaluator was found to be statistically significant. Also, practitioner opinion indicated that the QEC was relatively easy to use, applicable to the workplace, and valuable in conducting assessments.

QEC Content and Application

In the first step of using the QEC, the examiner observes a task and determines the postures/movement frequency of four body areas. Table 1 presents the body part options. Generally, for a given body part, one posture description and one movement frequency is chosen to describe the task.

The second step in using the QEC involves interviewing the worker relative to several key risk factors listed in Table 2.

Guidance is given for each risk factor descriptor (i.e., for maximum weight handled, light is 5kg or less, Moderate is 6 to 10 kb, Heavy is 11 to 20 kg, and Very Heavy is more than 20 kg).

 QEC Scoring

While acknowledging that research has indicated combining risk factors increases the incidence of injury, the authors note that proper weighting of various ergonomic concerns remains nebulous. A compromise was developed that allows for a gradient score of combined risk factors. Through addition, a score for a specific body part and a total score for a task can be calculated. Table 3 presents the scoring range of risk factor combinations for specific body regions and other ergonomic concerns.