Data processing costs for three posture assessment methods

Abstract

BackgroundData processing contributes a non-trivial proportion to total research costs, but documentation of these costs is rare. This paper employed a priori cost tracking for three posture assessment methods (self-report, observation of video, and inclinometry), developed a model describing the fixed and variable cost components, and simulated additional study scenarios to demonstrate the utility of the model.MethodsTrunk and shoulder postures of aircraft baggage handlers were assessed for 80 working days using all three methods. A model was developed to estimate data processing phase costs, including fixed and variable components related to study planning and administration, custom software development, training of analysts, and processing time.ResultsObservation of video was the most costly data processing method with total cost of € 30,630, and was 1.2-fold more costly than inclinometry (€ 26,255), and 2.5-fold more costly than self-reported data (€ 12,491). Simulated scenarios showed altering design strategy could substantially impact processing costs. This was shown for both fixed parameters, such as software development and training costs, and variable parameters, such as the number of work-shift files processed, as well as the sampling frequency for video observation. When data collection and data processing costs were combined, the cost difference between video and inclinometer methods was reduced to 7%; simulated data showed this difference could be diminished and, even, reversed at larger study sample sizes. Self-report remained substantially less costly under all design strategies, but produced alternate exposure metrics.ConclusionsThese findings build on the previously published data collection phase cost model by reporting costs for post-collection data processing of the same data set. Together, these models permit empirically based study planning and identification of cost-efficient study designs.

Cost-efficient assessment of biomechanical exposure in occupational groups, exemplified by posture observation and inclinometry

“…Data were successfully processed for all these files, except for one inclinometer file which had excessive noise. The data collection methods are described in detail in a separate report (35), as are the data processing methods (37).…”

“…In terms of variable costs, Ċ T is the cost of training staff to collect and process data specific to the measurement method; Ċ V is the cost of traveling to the worksite for data collection (depending on the number of trips), Ċ H is the cost of hotel accommodations during overnight trips (depending on the number of nights); Ċ R is the cost of recruiting workers at the worksite (depending on unit cost of recruiting a worker, ċ R , and the number of workers recruited); Ċ D is the cost of onsite data acquisition (depending on the unit cost of a measurement day, ċ D , and the number of data collection days); and Ċ M is the cost of managing the processing of daily data files (depending on the unit cost of processing a data file, ċ F, and the number of data collection days). Equation 1 is an amalgamation of previously-published cost models for data collection (35) and data processing (37). All costs were converted from Swedish kronor to euros using average annual exchange rate for the calendar years data were collected or processed.…”

“…Comprehensive costs for data collection and processing were tracked throughout these phases and used to developed cost models; these methods have been reported in detail elsewhere (35,37). In brief, the time for all research staff was recorded and summarized for all major research tasks for both measurement methods, from study planning to worksite measurements to data management.…”

“…In order to appreciate this trade-off and decide which measurement method to prefer from a cost-efficiency point of view, costs and efficiency must be quantified for each measurement class under realistic data collection scenarios and then compared (18). However, there have been few comprehensive efforts to report the empirical costs of biomechanical exposure assessment, and these preliminary efforts did not include any information on the quality or statistical properties of exposure information delivered (35)(36)(37). Recently some studies have combined empirical costs and precision of occupational exposure estimates, although these have addressed cost efficiency in general terms (20), or have focused on a narrow assessment of cost and compared sampling or analysis strategies just within a single method [in casu, observation; (19,21)].…”

Prediction of objectively measured physical activity and sedentariness among blue-collar work using survey questionnaires

“…Thus, accelerometer recordings have been used as the gold standard for validating questionnaire-based data on time spent sedentary and in physical activity (20,21). However, accelerometers demanding more resources to use than questionnaires (22), disqualifing them from most large-scale studies.…”