Footnotes

• Contributors SG and RP had the original idea for the study; XL and SG drafted the research letter; AL and XL conducted the data analysis; XL, AL, TT and SG gave substantial contribution to conception, design and interpretation of data; RP and LS gave contributions to conception and design of the study and provided data from the survey; all authors critically revised the manuscript and approved its final version.

• Funding The surveys were conducted with the contribution of the Italian Ministry of Health. The work of RP was partially funded by the Italian Ministry of Health (MADES project, chapter 4100/22). The work of AL was supported by a fellowship from the Italian Association for Cancer Research (AIRC). The work of SG and XL was partially supported by the Italian League Against Cancer (Milan).

• Competing interests None declared.

• Ethics approval The ethics committee of Istituto Neurologico Carlo Besta–Milano acknowledged the collection of anonymous data in face-to-face population-based, observational, cross-sectional studies (File number 37, 2017).

• Provenance and peer review Not commissioned; externally peer reviewed.

• Data sharing statement No additional unpublished data are available.