It's pretty hard to get clarification on a 100% "anonymous" report.
In my experience a lot of "anonymous" reports (no, no, not all) are less about real company organisational issues, and more about tearing down a workmate or a contractor or deflecting blame for your own f*ckups.
There is a real art to having a JUST culture - a blameless culture will allow the dead!!!!s to get away with murder by simply lodging a report - and a truly just culture will almost obviate the need for "anonymous" reports.
I was employed as safety manager at an organisation where I was told "We have bought a SMS, it's called Air Maestro"
While Air Maestro is not a "SMS" and it is not a cure-all, it does permit smaller organisations a structure around which they can *build* an SMS and put a lot of compliance management tools in place.
A work in progress...