Re: Distinguishing opinion from evidence in guidelines
I note that there are a few self-styled definitions of evidence in the responses to this article, so I also would like to throw-in my 2 cents worth also.
Def: Evidence = 'facts in context'.
This a very simple but useful definition when considering what constitutes evidence within Evidence Based Medicine.
1. A fact without context can not be evidence. A fact is merely a piece of information that may or may not be relevant in any given situation. For example, a common fact touted in Australia (especially during heatwaves) is "you can never drink too much water". But the evidence shows that you can indeed drink too much water, leading to homeostasis issues, electrolyte issues, cardiac issues and death issues by water intoxication. For a fact to hold true as evidence, it must be in context.
2. Context is what positions the facts to be evidence. The fact that drinking water is essential for our bodies needs context to be an evidence based statement. Again to use our example of water intake, without knowing what the context is (whether it is a 42 Celsius day, or fluid restriction for CHF), we aren't to know what the parameters and relevance around the fact are, which is what context provides. Without context, the fact is not evidence, whilst simultaneously being at the mercy of variables, taking it further away from being evidence based.
3. Evidence is facts in context. Within its stated context, the fact that underpin the evidence, and produces the expected outcomes repeatedly, can not be disputed. The evidence for optimal water consumption suggests that for an average adult, 2L a day of water is a good amount for optimal hydration, without extreme physical stress leading to excessive sweating and electrolyte loss. We know this to be true for the vast majority of adults, whom fit the context-driven criteria for the facts to be undisputed and proven repeatedly. Here we have the fact and the context for that fact, which is what underpins the evidence on this.
With all this in mind, all this is not to say that the evidence can't change. But that also is the point. Facts are only evidence when they are in context. If the context changes, the evidence changes too.
With facts in context, we can expect the same outcome (with all variables taken into account) no matter how many times the evidence is tested. It is this principle that makes science, science. And it is also this principle upon which EBM is founded and that the evidence base is expanded.
Rapid Response:
Re: Distinguishing opinion from evidence in guidelines
I note that there are a few self-styled definitions of evidence in the responses to this article, so I also would like to throw-in my 2 cents worth also.
Def: Evidence = 'facts in context'.
This a very simple but useful definition when considering what constitutes evidence within Evidence Based Medicine.
1. A fact without context can not be evidence. A fact is merely a piece of information that may or may not be relevant in any given situation. For example, a common fact touted in Australia (especially during heatwaves) is "you can never drink too much water". But the evidence shows that you can indeed drink too much water, leading to homeostasis issues, electrolyte issues, cardiac issues and death issues by water intoxication. For a fact to hold true as evidence, it must be in context.
2. Context is what positions the facts to be evidence. The fact that drinking water is essential for our bodies needs context to be an evidence based statement. Again to use our example of water intake, without knowing what the context is (whether it is a 42 Celsius day, or fluid restriction for CHF), we aren't to know what the parameters and relevance around the fact are, which is what context provides. Without context, the fact is not evidence, whilst simultaneously being at the mercy of variables, taking it further away from being evidence based.
3. Evidence is facts in context. Within its stated context, the fact that underpin the evidence, and produces the expected outcomes repeatedly, can not be disputed. The evidence for optimal water consumption suggests that for an average adult, 2L a day of water is a good amount for optimal hydration, without extreme physical stress leading to excessive sweating and electrolyte loss. We know this to be true for the vast majority of adults, whom fit the context-driven criteria for the facts to be undisputed and proven repeatedly. Here we have the fact and the context for that fact, which is what underpins the evidence on this.
With all this in mind, all this is not to say that the evidence can't change. But that also is the point. Facts are only evidence when they are in context. If the context changes, the evidence changes too.
With facts in context, we can expect the same outcome (with all variables taken into account) no matter how many times the evidence is tested. It is this principle that makes science, science. And it is also this principle upon which EBM is founded and that the evidence base is expanded.
Competing interests: No competing interests