The principle of an ‘intention to treat’ analysis is that the participants in a randomised trial are analysed in the group to which they were randomised, regardless of what treatment they received. So in a hypothetical trial of salbutamol vs. aminophiline infusion for severe asthma, regardless of what the child got, they are placed in their ‘you […]
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Bunging up the flow
I was intrigued to see the meta-analysis of diosmectite in acute diarrhoea appear in the Arch Dis Child recently – partly ’cause I’d no idea what diosmectite was, and partly because I spend a lot of my time with folk who poo too little or too much. When taking a look at a systematic review, […]
Making decisions to limit treatment in life-limiting and life-threatening conditions in children
The revised Royal College of Paediatric and Child Health guidance on making decisions to limit treatment in life-limiting and life-threatening conditions in childhood has just been published. It provides an ethical and legal framework for practicing clinicians revised to reflect the changes in the scope and availability of advanced technology and in the emphasis and […]
How do you add up if there are no numbers: Qualitative Synthesis
Regular readers of this blog will know of its penchant for systematic review techniques (evidenced in the recent I-squared blog ). The process of qualitative synthesis uses many of those familiar methods – defining a clear question, systematic literature searching, selecting appropriate research and assessing the risk of bias. Following this, however, qualitative syntheses begin […]
StatsMiniBlog: I-squared
No, not -1, the self-multiplication of that fancy imaginary number that helps aircraft designers make wings work properly, but a (semi) quantitative assessment of how much heterogeneity there is in a meta-analysis: I² You’ll recall that the idea of heterogeneity (mixed-up-ness) comes in both statistical and clinical flavours. This measure – I² – assesses the statistical […]
Thoughts from the School Run
“Hello? Is that the school? Yes, hi, it’s Ian here. I’m one of the dads. Anyway, I just thought I’d tell you that I’ve sent the kids to school with peanut brittle today. Yes, that’s right, peanut brittle. Yes, that does contain nuts. OK, thanks – bye!” (Some minutes later a SWAT squad paid a […]
StatsMiniBlog: Recursive partitioning
If you want to know who does, and who does not, need a bone marrow biopsy to detect malignant infiltration if the patient has rhabdomyosarcoma, you might want to start by taking a very large cohort of patients who had RMS and had a load of tests, including marrows. Then construct a decision tree that settles […]
What about mixedupness?
The subject of heterogeneity (mixed~up~ness) in systematic reviews is tricky. A bit like ‘significance‘ you can think about it as both a clinical and statistical concept, and in the same way, you can get results that aren’t always concordant. Many old lags will remember a blog post about a statistically significant association between platelets and renal […]
More than numbers: Assessing quality in qualitative research
So now to go back to one of the big questions from the first blog of this series – ‘How are you even supposed to tell if a qualitative paper is even any good when there are no power calculations, blinding or difficult stats?’ Hopefully, if you’ve been reading through each blog, you might have […]
When is enough enough?
I know that’s a tricky question, and may make you think of cream pouring on apple crumble, discussions about chemotherapy, or episodes of Octonauts depending on exactly what frame of mind you’re in and background you have. Within a research setting, however, how do we decide when something has been researched so much and folk have […]