## 3 Results
### 3-Month Rehospitalization and MPV Relationship  
Regarding the relationship between MPV and 3-month rehospitalization studied in the sample of patients with HF in our study, it was found that patients who were rehospitalized at 3 months had a higher MPV value compared to those who were not rehospitalized at 3 months. These data are graphically represented in the figure below (Figure 10), in which it can be observed that patients with HF rehospitalized at 3 months (1) had a higher MPV value (over 9 fl) compared to those who were not rehospitalized at 3 months (0).  
The explanations of the above phenomenon are better conveyed by applying the logistic regression model, the estimated coefficients for which are shown in Table 5, a model by which we were able to predict the probability that a patient with HF will be rehospitalized at 3 months based on the MPV value.  
The model applied in this case is the following: score (event occurrence = 3-month rehospitalization) = \(-\)8.4881 + 0.8359 \(\times\) MPV. Starting from this model, let us assume that we have a patient with an MPV of 9 fl. From here, applying the above-mentioned mathematical formula, the score for this patient is \(-\)0.96. To be able to interpret this result in terms of probability, we apply the following equation: \(\mathbf{p}=\frac{\mathbf{1}}{1+e^{-\delta w}}\). So, the probability of a patient with an MPV of 9 fl is 0.29, representing a 29% chance to be rehospitalized at 3 months.  
Figure 10: MPV value in HF patients who were rehospitalized at 3 months (1) versus HF patients who were not rehospitalized at 3 months (0).  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Dep.** & **Re\_Hosp\_3** & **No.** & **260** & & \\
**Variable:** & **mo\_** & **Observations:** & & & \\ \hline Model: & Logit & Df Residuals: & 258 & & \\ Method: & MLE & Df Model: & 1 & & \\  & & Pseudo R-squ.: & 0.06118 & & \\ Converged: & TRUE & LL-Null: & \(-\)154.36 & & \\ \hline  & Coef & std err & Z & \(p>1\,\mathrm{z}\,\mathrm{!}\) & [0.025 & 0.975] \\ \hline Intercept & \(-\)8.4881 & 1.845 & \(-\)4.601 & 0 & \(-\)12.104 & \(-\)4.873 \\ MPV & 0.8359 & 0.202 & 4.14 & 0 & 0.44 & 1.232 \\ \hline \hline \end{tabular}
\end{table}
Table 5: The relationship between MPV and the probability of 3-month rehospitalization, explained by the logistic regression model in patients with HF.  
The mathematical model described above and applied to HF patients rehospitalized at 3 months is statistically significant because the _p_-value associated with the coefficient for MPV (0.8359) is 0.000.  
The results obtained following the applied mathematical formula referred to above, are exemplified graphically in the figure below (Figure 11), in which we observe that patients with an MPV value of 7 fl had a probability of under 10% to be rehospitalized at 3 months versus patients with an MPV value of 9 fl who had a probability of over 20% to be rehospitalized at 3 months.  
Thus, starting from the arguments above, it can be said that, depending on the MPV value, we can predict the probability that a patient with HF will be rehospitalized at 3 months, and that patients with a higher MPV value have a greater probability to be rehospitalized at 3 months compared to patients with a lower MPV value.