Posted By Kevin Thompson
In order to answer your question, it would be first considering what the scope of the audit will be. Audits normally check for compliance. What do you want to confirm compliance against? Relevant Health and Safety Legislation or your own safety standards and systems.

You also need to consider the coverage of the audit. Do you want a high level audit that just confirms that the correct standards and systems are in place or do you want to test for compliance with them and if so do you want to carry out a sample of the Trust or to look at all operational units?

Regarding organisations, it might be worthwhile setting a minimum standard for the auditors (eg. MIOSH and Lead Auditor trained) and to choose organisations with names that people will recognise; when you state that you have been audited by such and such a body, unfortunately the better known the name the more credibility it might carry.

Have you consider approaching the Trust's insurers? they may offer an audit at a favourable rate knowing that it may reduce claims.