## 3 Results
### Outcomes and Estimation
#### 3.3.3 User Acceptance of mHealth App by SUS  
The SUS was the most significantly affected questionnaire due to participant attrition throughout the study. While 77 questionnaires were completed at baseline, this number decreased to 27 (35%) by the final follow-up, resulting in a low retention rate of 35.06%. Consequently, the SUS analysis was conducted using data from these 27 complete questionnaires across all data collection points (Table 5).  
At recruitment, most participants (\(n\) = 10 out of 27, 37%) rated the system as experiencing \"usability issues\" (level 50-70) and as \"acceptable to good\" (level 70-85). This could be attributed to participants' prior technological proficiency and their ability to adapt to the evolving nature of the mHealth app, which was still under development. During the study, the percentage of participants who rated the system as having \"excellent usability\" (level > 85) increased from 14.82% to 22.22%. This improvement can likely be attributed to the ongoing upgrades made to the mHealth app in collaboration with technical partners.  
\begin{table}
\begin{tabular}{l c c c} \hline \hline \multirow{2}{*}{**Level**} & **Recruitment (N = 78)** & **Last Follow-Up (N = 78)** & \multirow{2}{*}{_p-Value_} \\  & **\(n\) (\%)** & & **\(n\) (\%)** & \\ \hline \multirow{2}{*}{Level 1} & 5 (6.4) & 6 (7.7) & \multirow{2}{*}{1.0} \\  & 95\% C.I.: [2.2 to 14.9] & 95\% C.I.: [3.0 to 16.6] & \\ \multirow{2}{*}{Level 2} & 15 (19.2) & 16 (20.5) & \multirow{2}{*}{1.0} \\  & 95\% C.I.: [11.7 to 30.8] & 95\% C.I.: [12.7 to 32.3] & \\ \multirow{2}{*}{Level 3} & 33 (42.3) & 28 (35.9) & \multirow{2}{*}{0.49} \\  & 95\% C.I.: [32.6 to 55.9] & 95\% C.I.: [26.4 to 49.3] & \\ \multirow{2}{*}{Level 4} & 25 (32.1) & 28 (35.9) & \multirow{2}{*}{0.65} \\  & 95\% C.I.: [22.9 to 45.2] & 95\% C.I.: [26.4 to 49.3] & \\ \hline \hline \end{tabular}
\end{table}
Table 4: PAM Results: Comparison of the percentage of patients in each level at the recruitment vs. at the last follow-up (\(p\)-values have been calculated with McNemar test, C.I.: confidence interval).  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multicolumn{2}{c}{**Factor 1: Understand and**} & \multicolumn{2}{c}{**Factor 2: Maintain Positive**} & \multicolumn{2}{c}{**Factor 3: Seek and Obtain**} \\  & **Participate in Care** & \multicolumn{2}{c}{**Attitude**} & \multicolumn{2}{c}{**Information**} \\ \hline \multirow{3}{*}{**Recruitment**} & **Last Follow-Up** & **Recruitment** & **Last Follow-Up** & **Recruitment** & **Last Follow-Up** \\ \hline N & 75 & 75 & 75 & 75 & 75 & 75 \\ Mean & 13.73 & 13.75 & 13.28 & 13.17 & 13.81 & 13.55 \\ Median & 14 & 14 & 14 & 14 & 15 & 14 \\ Std. Deviation & 1.9 & 2.01 & 2.3 & 2.44 & 2.31 & 2.21 \\ Minimum & 9 & 9 & 6 & 4 & 7 & 8 \\ Maximum & 16 & 16 & 16 & 16 & 16 & 16 \\ Percentiles 25 & 12 & 12 & 12 & 12 & 12 & 12 \\
50 & 14 & 14 & 14 & 14 & 15 & 14 \\
70 & 16 & 15 & 15 & 15 & 16 & 16 \\ \(p\)-value & 0.98 & 0.66 & 0.25 & \\
95\% C.I. & [\(-\)0.99 to 0.50] & [\(-\)0.50 to 0.99] & [\(-\)1.00 to 1.31 \(\times\) 10\({}^{-5}\)] \\ \hline \hline \end{tabular}
\end{table}
Table 3: Descriptive statistics of CASE-Cancer Results (C.I.: Confidence interval).  
At the final follow-up, the most frequently reported score group for the system was \"Experiencing usability issues\" (level 50-70), which could be explained by negative feedback from patients regarding the increasing complexity of the system.