case_images: PMC11769950_01
case_images: PMC11769950_02
case_images: Simplified system boundaries of the analyzed operational models for conducting a clinical trial: center-based/traditional (A) and decentralized (B).
case_images: fpubh-12-1508166-g001.jpg
case_images: PMC11769950_02_fpubh-12-1508166-g001.jpg
case_images: fig1
case_images: The scope of this LCA study is shown in Figure 1. In addition, a courier service was included to model the single delivery of all sampling materials at the start of the trial and the collection back of biological samples at relevant time-points; however, the actual biological sampling kit is excluded from the system boundaries because it is the same in both clinical trial models (Figure 1). It includes the characteristics of the analyzed operational models for conducting clinical trials, particularly the number of visits (whether in-person or virtual), the use of paper and internet access to respond to questionnaires, the transport of the participant to the study center (traditional model), courier services for delivering collection kits and collecting biological samples (mainly for the decentralized model, and to some extent in the traditional model, if the participant was unable to provide fresh stools on the day of the study visit), and paper waste treatment (Figure 1). The analyzed systems for conducting clinical trials were modeled in SigmaPro v9.3.0.3 software, according to the systems illustrated in Figure 1.
case_images: Map of Singapore. Our representation based on a shapefile from Hijmans.
case_images: fpubh-12-1508166-g002.jpg
case_images: PMC11769950_02_fpubh-12-1508166-g002.jpg
case_images: fig2
case_images: Considering that the mainland of Singapore measures approximately 27 km from north to south and 50 km from east to west (Figure 2), an average distance of 25 km was considered between the study center, the subject's location, and the courier service base to model the transport of the participant to the study center and courier services (from the subject's location to courier service base and from study center to courier service base).