Interestingly, from a systematic analysis of the Global Burden of PD between 1990 and 2016, a positive trend emerged between the socio-demographic index (SDI) of a country and the age-standardized prevalence of PD as well as the age-standardized rate of disability-adjusted life-years, defined as the sum of years lived with disability and years of life lost [ 28 ].
1
—
—