Table 4. Items and results of the pre-test and post-test satisfaction questionnaire and concerning the instruction notice (substudy 1), the performing of the Exacto COVID-19 self-test (Biosynex Swiss SA) (substudy 2), and the interpretation of test results (substudy 3).
| Satisfaction questionnaire | Pre-test satisfaction | Post-test satisfaction | Difference* | P-value# |
|---|---|---|---|---|
| % [95% CI] | ||||
| [number (%)] | [number (%)] | |||
| How did you find the understandability of instructions for use of self-test? (N = 167) | ||||
| Very easy | 156 (93.4) | 153 (91.6) | -1.8 (-5.1 to +1.5) | NS |
| Rather easy | 11 (6.6) | 10 (6.0) | -0.6 (-3.3 to +2.1) | NS |
| Rather difficult | 0 (0) | 2 (1.2) | +1.2 (-1.8 to +4.2) | NS |
| Very difficult | 0 (0) | 2 (1.2) | +1.2 (-1.8 to +4.2) | NS |
| How did you find the identification of the different components of the self-test kits? (N = 83) | ||||
| Very easy | 81 (97.6) | 80 (96.4) | -1.2 (-6.5 to +4.3) | NS |
| Rather easy | 2 (2.4) | 3 (3.6) | +1.2 (-4.1 to +6.5) | NS |
| Rather difficult | 0 (0) | 0 (0) | - | NA |
| Very difficult | 0 (0) | 0 (0) | - | NA |
| How did you find the sample collection? (N = 83) | ||||
| Very easy | 77 (92.8) | 59 (71.1) | -21.7 (-31.7 to -11.7) | <0.001 |
| Rather easy | 5 (6.0) | 20 (24.1) | +18.1 (+11.3 to +27.7) | <0.001 |
| Rather difficult | 0 (0) | 1 (1.2) | +1.2 (-4.1 to +6.5) | NS |
| Very difficult | 1 (1.2) | 3 (3.6) | +2.4 (-3.5 to 8.3) | NS |
| How did you find the sample transfer? (N = 83) | ||||
| Very easy | 68 (81.2) | 50 (60.2) | -21.0 (-30.9 to 11.1) | <0.001 |
| Rather easy | 14 (16.9) | 25 (30.1) | +13.2 (+4.3 to +22.1) | 0.043 |
| Rather difficult | 0 (0) | 2 (2.4) | +2.4 (-3.5 to +8.3) | NS |
| Very difficult | 1 (1.2) | 6 (7.2) | +6.0 (-1.3 to +13.3) | NS |
| How did you find the overall performance of self-test? (N = 83) | ||||
| Very easy | 80 (96.4) | 77 (92.8) | -3.6 (-10.1 to +2.9) | NS |
| Rather easy | 2 (2.4) | 6 (7.2) | +4.8 (-2.1 to +11.7) | NS |
| Rather difficult | 1 (1.2) | 0 (0) | -1.2 (-6.5 to +4.3) | NS |
| Very difficult | 0 (0) | 0 (0) | - | NA |
| How did you find the reading of strips after migration? (N = 84) | ||||
| Very easy | 73 (86.9) | 70 (83.3) | -3.6 (-10.0 to +3.0) | NS |
| Rather easy | 8 (9.5) | 10 (11.9) | +2.4 (-3.4 to 8.4) | NS |
| Rather difficult | 2 (2.4) | 3 (3.6) | +1.2 (-4.0 to +6.4) | NS |
| Very difficult | 1 (1.2) | 1 (1.2) | - | NA |
| How did you find the interpretation of self-test results? (N = 84) | ||||
| Very easy | 76 (90.5) | 76 (90.5) | - | NA |
| Rather easy | 8 (9.5) | 7 (8.3) | -1.2 (-6.4 to +4.2) | NS |
| Rather difficult | 0 (0) | 0 (0) | - | NA |
| Very difficult | 0 (0) | 1 (1.2) | +1.2 (-4.0 to +6.4) | NS |
| How did you find your ability to surmount the difficulties encountered? (N = 167) | ||||
| Very easy | - | 162 (97.0) | NA | NA |
| Rather easy | - | 5 (3.0) | NA | NA |
| Rather difficult | - | 0 | NA | NA |
| Very difficult | - | 0 | NA | NA |
* Difference and CI were assessed with the Wilson score bounds using data collected in the post-test satisfaction questionnaire paired to those from the pre-test satisfaction questionnaire;
# P-value calculated using Mac Nemar’s test of paired data.
CI: Confidence interval; NA: Not applicable; NS: Not significant.