Table 6 Fixed effects panel model (HAC) $\begin{array}{l}\mathit{I}\mathit{R}{\mathit{M}}_{\mathit{it}}={\beta }_{1}OBT{B}_{\mathit{it}}+{\beta }_{2}DummyUNDE{R}_{\mathit{it}}+{\beta }_{3}DummyOVE{R}_{\mathit{it}}+{\beta }_{4}OBPO{P}_{\mathit{it}}+{\beta }_{5}OTHPER{S}_{\mathit{it}}+{\beta }_{6}NOTHPER{S}_{\mathit{it}}+\\ {\beta }_{7}PHAR{M}_{\mathit{it}}+{\beta }_{8}TOTPRO{D}_{\mathit{it}}+{\alpha }_i+u_{\mathit{it}}\end{array}$

From: Patients’ mobility as an indicator for (in)efficiency:a panel data analysis on Italian health care authorities