npj Parkinsons Dis: What inspires us about Parkinsons morbidity, prevalence and mortality across Norway?

Parkinson's disease (PD) is the second most common neurodegenerative disorder and the fastest growing neurological disorder in terms of morbidity, associated disability and mortality

Figure 1 Title map of the paper

Several studies have assessed descriptive epidemiological aspects (eg, incidence, prevalence, and mortality) of PD in different populations worldwide

In addition, men have higher incidence and prevalence of PD compared with women, although the ratio of men/women varies widely across studies and is lower in Asian populations

Although some studies have shown that men with PD have a higher risk of death than women, these studies did not take into account the increased risk of death in men in the general population

Differences between epidemiological studies are often attributed to small sample sizes, confirmation bias, biological differences (eg, population heterogeneity), and methodological differences, such as changes in practice and/or diagnostic criteria over time

In the current study, Brage Brakedal lamps at Haukeland University Hospital, Norway, used the Norwegian Drug Prescription Database (NorPD) to assess the incidence, prevalence and mortality of PD in the entire Norwegian population between 2004 and 2017

The prevalence in males/females of all ages was 1.

Figure 2 PD incidence and prevalence 

Although mortality in PD is generally higher than in the general population, the mortality ratio decreases with age, approaching 1.

When adjusted for sex-specific mortality in the general population, female PD patients had an equal or higher mortality rate than male PD patients

These results suggest that: Epidemiological characteristics of PD, including sex differences, are age- and time-dependent , and suggest that sex differences in PD mortality are unlikely to stem from the disease's specific negative impact on male survival