Blog entry by Arif Khwaja
Once I have had a chance to digest the KDIGO guidelines I will post some thoughts. I note there has been much interest on the KDIGO guidelines on this site. A few things caught my eye - like the suggestion for fish oils in IgA nephropathy. This is based on data by Donadio and colleagues showing a beneficial effect. This has never been reproduced anywhere else and the control group in that study did extraordinarily badly - around 40% ended up on RRT. KDIGO not unreasonably suggest that fish oils are relatively safe and therefore make a 2D recommendation about their use.
In fact 36% of all the statements in the glomerulonephritis guidelines are 2D. And to remind ourselves what does 2D mean? Well '2' is a suggestion and '1' is a recommendation. D means that the quality of evidence that the suggestion is made is ' very low - the estimate of the effect is very uncertain and often will be far from the truth' - to me 2D sounds a lot like opinion and theres nothing wrong with opinion but we need to recognise it as opinion and not fact. If we are going to get the most out of guidelines we need to learn how to read them or perhaps just have guidelines about things for which there is good evidence.