Patient Safety Program



The five rules of causation are designed to improve the RCA process by creating minimum standards for where an investigation and the results should be documented. The rules are created in response to the very real biases we all bring to the investigation process.

Rule 1 - Causal Statements must clearly show the "cause and effect" relationship.

This is the simplest of the rules. When describing why an event has occurred, you should show the link between your root cause and the bad outcome, and each link should be clear to the RCA Tearn and others. Focus on showing the link from your root cause to the undesirable patient outcome you are investigating. Even a statement like "resident was fatigued" is deficient without your description of how and why this led to a slip or mistake. The bottom line: the reader needs to understand your logic in linking your causes to the outcome.

Rule 2 - Negative descriptors (e.g., poorly, inadequate) not used in causal statements.

As humans, we try to make each job we have as easy as possible. Unfortunately, this human tendency works it way into the documentation process. We may shorten our findings by saying "maintenance manual was poorly written" when we really have a much more detailed explanation in our mind. to force clear cause and effect descriptions (and avoid inflammatory statements), we recommend against the use of any negative descriptor that is merely the placeholder for a more accurate, clear description. Even words like "carelessness" and "complacency" are bad choices because they are broad, negative judgments that do little to describe the actual conditions or behaviors that led to the mishap.

Rule 3 - Each human error must have a preceding cause.

Most of our mishaps involve at least one human error. Unfortunately, the discovery that a human has erred does little to aid the prevention process. You must investigate to determine WHY the human error occurred. It can be a system-induced error (e.g., step not included in medical procedure) or an at-risk behavior (doing task by memory, instead of a checklist). For every human error in your causal chain, you must have a corresponding cause. It is the cause of the error, no the error itself, which leads us to productive prevention strategies.

Rule 4 - Each procedural deviation must have a preceding cause.

Procedural violations are like errors in that they are not directly manageable. Instead, it is the cause of the procedural violation that we can manage. If a clinician is violating a procedure because it is the local norm, we will have to address the incentives that created the norm. If a technician is missing steps in a procedure because he is not aware of the formal checklist, work on education.

Rule 5 - Failure to act is only causal when there was a pre-existing duty to act.

We can all find ways in which are investigated mishap would not have occurred--but this is not the purpose of causal investigation. Instead, we need to find out why this mishap occurred in our system as it is designed today. A doctor's failure to prescribe a medication can only be causal if he was required to prescribe the medication in the first place. The duty to perform may arise from standards and guidelines for practice; or other duties to provide patient care.


*Adapted from David Marx