Comparative Survey-Based Study of Noninvasive Saliva Collection Devices

While saliva is a valuable sample for noninvasive diagnosis, the usability of saliva collection devices can impact its effectiveness in diagnostics. To address this, we evaluated five saliva collection devices: Salivette (swab), SuperSAL (swab), SalivaBio Passive Drool, Medschenker Saliva Collection Kit (funnel), and a cryovial with funnel used in SwabSeq coronavirus disease 19 (COVID-19, SARS-CoV-2) tests. Saliva collection rates and instruction reading rates for each device were measured for 60 healthy adults. Users then reported the difficulties of instructions, assembly, and saliva collection, and whether there was leakage of saliva through a survey. Unstimulated saliva production (=flow) rates and base reading rates for each user were measured for normalization. Device metrics were compared using permutation tests and one-way analysis of variance (ANOVA). Salivette collected saliva easily and most quickly, while SuperSAL's collection was slower and rated difficult by users. Medschenker had high instruction reading rates and the lowest leakage rate. Users found the SwabSeq funnel and Passive drool's instructions easy, but found the devices themselves not easy to collect saliva with. Overall, Medschenker performed well on most metrics, while SuperSAL did not perform as well. Our results show that no single saliva collection device satisfies all requirements of an ideal device: a device that allows for efficient, easy, and safe saliva collection without leakage. With the findings from our study, we aim to guide researchers and clinicians in choosing the appropriate saliva collection device in their practices and to motivate the design of an ideal saliva collection device.