“…Conversely, most authors used this tool to indirectly examine sleep quality through specific measures, such as the fragmentation index and sleep latency, time, and efficiency. Overall, studies that used actigraphy in PD addressed the following four main issues: (i) assessment of sleep features [ 13 , 16 , 17 , 20 , 21 , 22 , 23 , 24 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 ]; (ii) evaluation of therapeutic interventions [ 14 , 15 , 83 , 89 , 90 , 91 , 92 , 93 , 94 ]; (iii) validation of clinical scales [ 95 , 96 ], and; (iv) identification of specific primary sleep disorders [ 18 , 19 ].…”