Adverse Event: Causes

Often, an adverse event will be the consequence of a sequence of errors or failures.

The causes of these failures and errors can be classified into:
1. immediate causes: the agent of injury or ill health (e.g. the mower blade);
2. underlying causes: unsafe acts and unsafe conditions (e.g. the safety guard was removed to the aerator or scarifier);
3. root causes: the failure which can be linked to other, often lesser, failures and errors (e.g. failure to identify training needs and assess competence, low priority given to risk assessment etc).

Effective risk controls are needed to address the three classes of causes: immediate, underlying and root. This positive action can help prevent the occurrence of an adverse event. (HSE (2004) ‘Investigating accidents and incidents', HSG245, p.6 https://www.hse.gov.uk/pubns/hsg245.pdf)