Comparative survey-based study of non-invasive saliva collection devices

Background We compared five saliva collection devices on their saliva collection efficiency, instruction reading rate, user difficulty ratings, and leakage of saliva, all of which are important factors in safe, easy, and efficient saliva collection. The devices evaluated were: Salivette (swab), SuperSAL (swab), SalivaBio Passive Drool, Medschenker Saliva Collection Kit (funnel), and cryovial with funnel used in SwabSeq COVID-19 surveillance tests. Methods 56 individuals used five devices in randomized orders by first reading the device’s instruction manual while timed, then self-collecting saliva while timed, to measure the instruction reading rate and saliva collection rate, respectively. For each device, users were asked about the difficulties of instructions; assembly; and saliva collection, and whether there was leakage of saliva. Lastly, unstimulated and stimulated saliva production (=flow) rates for each user were measured. The saliva collection and instruction reading rates were normalized by the individual’s base saliva flow rate and base reading rate. The rates and difficulty ratings for devices were compared using permutation tests and one-way ANOVA. Results Salivette had the highest average saliva collection rate and SuperSAL had the lowest. For the instruction reading rate, Medschenker’s funnel device had the highest average and Salivette had the lowest. While all devices showed saliva leakage, passive drool had the highest fraction of leakages and the Medschenker device the lowest. Users found the instructions for Salivette the hardest and those for SwabSeq the easiest. Users found the assembly for Medschenker to be easiest and that for SuperSAL to be hardest. Users rated Salivette easiest to collect saliva with, and SuperSAL most difficult. Conclusions Medschenker performed well on most qualitative and quantitative metrics while SuperSAL did not perform as well. However, no single saliva collection method or device satisfies all requirements of an ideal device. A device that allows for efficient saliva collection, easy usage, and safe saliva collection without leakage could greatly help standardize saliva collection.