Table 2 Observer assessment of errors (using a product-specific checklist), difficulties, and steps requiring assistance
Observation | % (n) of participants |
|---|---|
Observed errors at each step using the usability checklist | |
Pre-testing | |
 Opening the package | 0% (0/116) |
 Reading/using the instructions for use | 4.3% (5/116) |
 Removing the test tube from the test pack | 0% (0/116) |
 Removing the cap from the test tube | 0.8% (1/116) |
 Placing the tube into the stand | 4.3% (5/116) |
 Removing the test device from the test packa | 0% (0/115) |
Conducting the test | |
 Touched the flat pad | 4.3% (5/115) |
 Incorrect manipulation to collect oral fluid | 0.8% (1/115) |
 Incorrect placing of the test device in the test tube | 0.8% (1/115) |
 Test device came out of the tube while testing | 0% (0/115) |
 Incorrect timekeeping | 5.2% (6/115) |
Errors observed during at least one step | 12% (14/116) |
Test interpretation | |
 Interpreted test results incorrectly (the result read by the study participant was not in agreement with re-reading by a trained staff member) | 13.9% (16/115) |
Observed difficulties with testing steps | |
 Opening the package | 12.1% (14/116) |
 Removing the cap from the test tube | 41.4% (48/116) |
 Placing the tube into the stand | 18.1% (21/116) |
 Placing the test device into the tube | 2.6% (3/115) |
 Reading and interpreting the results | 2.6% (3/115) |
Experienced difficulties during at least one step | 53.4% (62/116) |
Assistance providedb | |
 Opening the package | 2% (2/116) |
 Opening and removing the cap from the tube | 4% (5/116) |
 Placing the tube into the stand | 7% (8/116) |
 Placing the test device into the tubea | 1% (1/115) |
 Reading the resultsa | 2.6% (3/115) |
Assistance provided during at least one step | 12.1% (14/116) |
Completed all testing steps correctly without any assistance and interpreted the test results correctly | 72% (84/116) |