We’re all well aware of the problems of doing randomised clinical trials in paediatrics – small numbers, uncertainty about sample size estimates, lack of funding to undertake the studies – but are we as aware of some alternative approaches that have been used [1]? “Sequential design” studies look at comparing a series of treatments against […]
Category: critical appraisal note
Cases and controls
I’ve noticed that there are a fair few phrases in the world where there actual meaning can be unclear or uncertain, or possibly interpreted differently by folk. Take “maybe later” when used by parent to child – clearly means “no” to the parent and “yes but not now” to the child. Or “brexit”. But the […]
Basics: Blame it on me
In my clinical role, it’s fairly easy to take the blame for most bad things that happen to my patients. I give them cytotoxic chemotherapy (for good reason, honest) and it’s a group of substances that we label with TERATOGENIC! HARMFUL! QUITE BAD FOR YOU! tags a lot of the time. But how do we […]
Get it straight from the start
Over more than a decade Archimedes has presented clinical queries and the appraisal of the evidence that emerges. leading on to a clinical conclusion to the dilemma. What is strikingly common is that many questions can start in a muddle, and a failure to get an ‘evidence based answer’ might be a failure to ask […]
Proof of equipoise
In order to test a new treatment, in a standard randomised controlled trial, we are ethically assumed to have ‘equipoise’: an honest uncertainty at the same chance of a patient being allocated to the new or old treatment. But, I hear you scoff, how can any investigator put themselves through the hell of ethical administration […]
Cracking the mould
While Archimedes does, not infrequently, get all concerned about invasive fungal infections, this post is not of the issue of beta-D-glucan testing, or problems of azole interactions. Instead, its a swipe at the problem of how, given a transparent system of asking questions, acquiring information, and appraising the evidence we can come to such […]
Tarnished gold
What can you do when a ‘gold standard’ isn’t actually that good at diagnosing a condition? It can be terribly problematic in interpreting sensitivity and specificity – for example comparing polymerase chain reaction diagnosis of microbiological infection with culture results. The ‘false positive’ may actually reflect real, and otherwise missed, diagnosis, and the ‘false negatives’ […]
Short-cuts to effectiveness information
A while ago Archimedes reviewed the benefits of using ‘pre-appraised’ search resources, short-cuts to the best methodological quality evidence to answer clinical questions. The favoured database of many, PubMed [www.pubmed.gov] has now receieved a new addition to the range of resources on offer. […]
Slice, DICE and eventually something will happen
Did you know that aspirin following MI doesn’t work for those with Gemini and Libra star signs? No, it’s true*. The ISIS-2 trial, which demonstrated the mortality benefits for anti-platelet agents after myocardial infarction with a p<0.00001 only showed benefit for people born in ten of the twelve signs of the zodiac.So if you believe […]
Secrets and lies. Truth and beauty.
… and other Bohemian aphorisms … There is a quite brilliant paper from the under-advertised PLoS One which shows how, in the are of incubation periods for respiratory disease, Truth By Citation is quite strikingly different than the reality of the evidence. The networks of citations demonstrate how repetition, sometime but not always with a […]