From [the learned] stewartb:

Quite a lot published on the significance of location of hand sanitisers in hospitals for levels of usage by visitors. From a very quick and non-expert root around the literature, I’m not sure this consultant’s point about sanitisers near the main entrance to the hospital is necessarily supported by evidence.

For example: Hobbs et al (2016) Visitor characteristics and alcohol-based hand sanitizer (AHS) dispenser locations at the hospital entrance: Effect on visitor use rates. American Journal of Infection Control Issue 3, 258-262

These authors conclude that the placement of an AHS dispenser in a lobby location is probably the least effective in terms of patient safety. And there is other evidence that compliance with the use of hand sanitisers is highest where these are provided close to clinical settings and to patients, e.g. at entrances to wards or even by sinks within wards.

Intuitively, the proximity of the AHS to the clinical setting could be more effective in ensuring ‘clean’ hands when the visitor, having passed through other public areas, finally approaches a patient.