Carnegie Mellon University

Daily Tissue Count (BCS)




To evaluate objective signs of illness associated with viral infection


On each day of the trial, participants collected their used tissues in plastic bags.  Every 24 hours, the tissues contained in the bags were counted and the number recorded.  A “baseline” tissue count was calculated for each participant by taking the average of the number of tissues used during the first three pre-challenge days.  Adjusted daily tissue counts were computed by subtracting the baseline count from the number of tissues used on each post-challenge day.


  • Number of post-challenge days on which at least one tissue was used
  • Total number of tissues used across all post-challenge days (adjusted for baseline)
  • Daily tissue score
    1. Participants were assigned a numeric score for each post-challenge day that was determined by the number of tissues used on that day (see below)
    2. Tissue scores for each post-challenge day were used in the creation of total daily symptom scores

Tissue Count Scores