Posts

More changes to survHE. Earlier this week, I gave a talk at the Virtual Ispor US conference (our panel was W11). In preparation for the panel (and other things I was doing anyway), I got to talk to colleagues and thought a bit more of how survival modelling in HTA is kind of weird and “special”… In particular, I realised how survHE doesn’t give by default any real information about the hazard and the cumulative hazard functions — this isn’t entirely true, because once the survival curve has been estimated (which is the whole point of survHE!

Philip Cooney has alerted me to a slight inconsistency in survHE. Basically, he was trying to work in a setting where the data contain no censoring, using the HMC/rstan models generated by survHE. All works OK when using some of the models implemented, but failed when trying to fit the Gamma, Generalised Gamma and Generalised F. The reason for this is that, for simplicity (and actually, our empirical tests show that computational run-time is much reduced) these models construct the log-likelihood by separating the set of individuals who are fully observed from the one of individuals who are censored.

This is, in many ways, very old news — but last summer (sic!) I applied for and was made the new Head of Department of UCL Statistical Science (and I think — checks in place — for the first time since the department was founded in 1911, the post has gone to somebody who isn’t British or from a Commonwealth country, of which I’m very proud — again, pending checks…).

A couple of colleagues have alerted us to some issues with the BCEA function evppi, under MS Windows. Basically, it seemed as if under MS Windows and with R 4.0.0 (which is a recent, though not the most recent release of R) the evppi function would break, when trying to make the analysis based on INLA (and the work discussed here).

Earlier this week, while I was working on my second-last lecture of the year (I’ve been relatively good and the vast majority of the new material I had to prepare to make everthing accessible — and I also took the chance to give my slides a little makeover, mostly learning and enjoying xaringan — but this one I kind of forgot I had to do it, so I needed to kind of do it quickly this week… But as usual, I digress…), I discovered a little bug in survHE.

Earlier today I finally managed to understand the process and then implement the renaming of the default branch in my GitHub repositories. This follows a relatively old controversy — all new repositories are now by default created with a “main” branch, rather than the old terminology “master”. I think it’s one of those things that make you feel ashamed because you haven’t thought of that before or managed to act more swiftly since you realise it.

I know… long time no speak and the rest… I do feel a bit guilty about it — and I do have lots of good excuses for not having posted almost at all in the recent past and definitely at all in the past 3 months (lockdown-cum-homeschooling is something I may want to discuss separately…). Anyway: a piece of news on survHE.

Last Friday on Monday, we held our online R-HTA workshop. We will discuss the feedback and agree on ways forward in the consortium Scientific Committee soon, but I thought I’d write down some personal reactions to the very interesting discussions — of course, what come out of all this eventually may well be very different to my synthesis! Still… I thought the two days went very well — I have enjoyed them very much and I think so did the participants.

This comes as the results of two external forces that have prompted me to do some work on the website — specifically the section on books. The first one is the newest version of hugo-academic (which is the engine underlying the whole of my website, together with the R package blogdown). This has a new facility that can be used to format books or tutorial or documentation.

Our paper on the CBD trial has just been published in The Lancet Psychiatry (and found its way through the media, for example here or here). Basically, the objective was to determine whether (a specific dose of) CBD was a safe treatment for cannabis addition (I’d already talked about this here and here). This has been quite a long process — I think even before I got involved there has been lots of work put in.