To obtain the most valid and reliable measurement, individuals are encouraged to weigh first thing in the morning, without wearing clothing, before eating/drinking and after voiding their bladder/bowels.
As calibration may be affected by shipment, individuals should weigh themselves (i.e., by stepping on the scale, waiting for a weight to appear, stepping off the scale, and allowing for the weight to transmit) at least three times. If weights do not appear stable, individuals should repeat this protocol and contact the clinicians/researchers for troubleshooting if the technical problems cannot be resolved. Clinicians/researchers can contact the scale manufacturer on the behalf of the individual for further troubleshooting as a final option.
Individuals are encouraged to refrain from moving the scale or storing it on its side, as this may require scale recalibration before each use. Participants should also discourage other family members from using the scale, unless the scale allows for separate profiles for multiple individuals; although some scale models “filter” out unlikely weights (as may be created by pets or other users), these extra measurements can cause challenges (procedures for “cleaning” e‐scale data have been described elsewhere (4, 5)). Finally, e‐scales may have transmission difficulties with weak cellular or wireless internet connections. Concrete walls can block cellular signals, so cellular scales should be placed near windows for optimal signal. Wireless internet scales should be placed near routers to improve signal strength. Moreover, many scales can retain weights for at least a week; thus, individuals who experience weak connections can weigh themselves and then move the scale to another location to transmit weights weekly.
An important consideration when choosing an e‐scale is how data will be accessed. Some e‐scales are primarily for consumer use and they have limited functionality for clinicians/researchers. Others allow data to be pulled via application‐program interface tools (which allow the e‐scale system to securely communicate with the clinician’s/researcher’s data management system, in order to transfer the requested weight data with date/time stamps), although this method often requires assistance from software developers. Finally, some scales have website portals allowing direct access to data from registered scales. Before selecting an e‐scale, clinicians/researchers need to answer the following questions. (1) In what format do you want to view data? (2) Do you need data immediately after transmission, or is it sufficient to receive “batches” of data at specified time points? (3) Is data transmission/storage compliant with the Health Insurance Portability and Accountability Act Privacy Rule (9)? Using third‐party platforms to collect, transmit, or store data has important security and confidentiality implications; thus, clinicians/researchers interested in implementing these tools should consult with their local privacy office or institutional review board staff. In general, using identifiable personal health information should be limited, and individuals should be informed if their data may be accessed or transmitted by third‐party sources.
Clinicians/researchers should also assess which e‐scale type (e.g., cellular, wireless internet, or Bluetooth models) would be feasible to implement with the target population. The limited setup required for cellular scales use can be helpful for users with low technology literacy; however, access to cellular signals may be limited in some areas (e.g., in low‐resource rural communities). Moreover, use may be limited for individuals with higher weights; existing scales typically have maximum weights between 150 kg and 180 kg.
The COVID‐19 pandemic requires particular consideration of disease transmission with e‐scales. Because the virus survives on cardboard for about 24 hours, it is recommended that individuals do not handle the box for 24 hours after delivery and that they wash their hands after opening the box to take out the scale. Considering that individuals may be averse to reuse of e‐scales that have been repeatedly used with bare feet or stored in the bathroom by others, e‐scales are often used by just one individual when provided in an interventional context. For one‐time assessments, scales can be mailed and cleaned (with hospital‐grade sanitizing or disinfecting wipes) between uses.