Table 3.

Available literature assessing the correlation between orphan drugs annual treatment costs and disease prevalence.

Publication	Year	Geographical scope	Number of orphan drugs analysed	Methodology	Results: correlation between annual treatment cost and disease prevalence
Alcimed [36]	2005	France	10	Public price including taxes (PPIT) used	Inverse
Messori et al. [37]	2010	Italy	17	Non-cancer orphan drugs included; Drug prices from Italian national drug regulatory agency used	Inverse
Aballéa et al. [38]	2010	France, Italy, Germany, Spain, UK	51	Public prices used	Inverse
Picavet et al. [14]	2014	Belgium, Czech Republic, France, Italy, the Netherlands, UK	59	Public prices used	Inverse
Onakpoya et al. [39]	2014	UK	74	Annual costs based on literature search	Inverse