I do some work for BMJ Evidence-Based Medicine and one aspect of this is looking for practice changing research. Part of this is exploring the Altmetrics for each article I find.

One article, with an exceptionally high Altmetric score (1629 as I type this) is Bedtime hypertension treatment improves cardiovascular risk reduction: the Hygia Chronotherapy Trial. The aim of the trial was “to test whether bedtime in comparison to usual upon awakening hypertension therapy exerts better cardiovascular disease (CVD) risk reduction.”  The trial concluded:

Routine ingestion by hypertensive patients of ≥1 prescribed BP-lowering medications at bedtime, as opposed to upon waking, results in improved ABP control (significantly enhanced decrease in asleep BP and increased sleep-time relative BP decline, i.e. BP dipping) and, most importantly, markedly diminished occurrence of major CVD events.

This reminded me of a question we’d been asked in the past. A bit of rummaging around and I found “am or pm what is the optimal time to take once a day antihypertensives?” which we answered in 2010.  In short the evidence found – back then – that bedtime was typically the better time to take this anti-hypertensives: giving better blood pressure control and reduction in events.

Why am I highlighting this?  One angle could be to question the necessity of the trial. I’m acutely aware of the work by the likes of Iain Chalmers and Paul Glasziou on research waste (eg Research waste is still a scandal). However, this is not something I’m in a position to comment on, I feel I don’t have the expertise.

But my fascination is why is got such a high Altmetric score. I see Altmetrics as a sign of interest and/or newsworthiness. But to me this is not new knowledge. It might now have more ‘power’ but I had thought that bedtime consumption of anti-hypertensives was, typically, the best thing to do.

So, to me, this demonstrates the difficulty of spreading knowledge. The knowledge has been known for years. The Altmetric score demonstrates there was a real hunger for the knowledge. Yet, somehow, until this new paper came out the knowledge was either inaccessible or clinicians didn’t articulate the question and search for the evidence! Slightly depressing either way….