[vhanda]

From the article -

> this paper was not a retrospective study of electronic health records, it was a randomized clinical trial, which is the gold standard. This means that we’ll be forced to immediately throw away our list of other obvious complaints against this paper. Yes, healthier patients may come in the morning more often, but randomization fixes that. Yes, patients with better support systems may come in the morning more often, but randomization fixes that. Yes, maybe morning nurses are fresher and more alert, but, again, randomization fixes that.

[leereeves]

> Yes, maybe morning nurses are fresher and more alert, but, again, randomization fixes that

How does randomization fix that?

[finnh]

exactly. that one clause casts doubt on all the other reasoning; randomization controls for patient selection bias but not diurnal clinic performance

[phanimahesh]

It would if the clinic is a controlled setting and they can control when the nursing shift begins.

[vibrio]

"Forced to throw away" biases is strong. If run well, RCTs surely help manage potential biases, but it does not eliminate them. The slides saw available on X-itter didn't show a Consort diagram (accounting of patient count between screening and endpoint) or the balance of patent characteristics between the arms. This seems to be a single site study, which is significant caveat IMO. The lack of substantial mechanistic explanation, and alleged study redesign mid-stream are also caveats. All that said the reported effect is very large, and I'd like to see a more detailed reporting and analysis. If the effect that size is real, it should be able to be found in some relatively quickly retrospective studies (yes, many caveats there, but that could probably provide very large numbers rapidly in support of the RCT).

[tines]

What does randomization mean in this context, and why does it fix those problems?

[ajkjk]

https://en.wikipedia.org/wiki/Randomized_controlled_trial

The same thing it means in every context: that (with enough samples) you can control for confounders.

[tines]

Supposing that patients did better in the morning because, say, the nurses were more alert, no matter how many samples you take you'll find the patients do better in the morning. How does "more samples" help control for confounders rather than just confirm a bias?

[JumpCrisscross]

> How does "more samples" help control for confounders rather than just confirm a bias?

I think you're correct that randomising patient assignments doesn't control for provider-side confounders. Curious if the study also randomised nursing assignments.

[ajkjk]

"more samples" is not what controls for confounders. Controlling for confounders is what controls for confounders, which you can only do with enough samples that you can randomize out the effect of the confounder.

Whether or not they controlled for nurse-alertness is something you'd have to read the paper (or assume the researchers are intelligent) for.

[tines]

I guess I'm asking, how do you randomize out the confounder in this case.

[ajkjk]

I imagine that that particular confounder is not possible to eliminate via randomization. Perhaps you collect a bunch of data on nurse awakeness--day shift vs night-shift, measuring alertness somehow, or measuring them on other activities known to be influenced by alertness--and then ensure your results don't correlate with that.

There is also the mechanistic side: if you have lots of plausible mechanism for what's going on, and you can detect indicators for it that don't seem to correlate with nurse alertness, that's a vote against it mattering. Same if you have of lots of expertise on the ground and they can attest that nurse alertness doesn't seem to have an affect. There are lots of ways, basically, to reach pretty good confidence about that, but they might not be as rigorous as randomized assignments can be.

[bravesoul2]

Have every dose be observed by another doctor?

[kelnos]

Patients in the study are randomly assigned to the early group or the late group. They don't get to schedule their own appointments for whatever time of day they want.

[tines]

How does this control for the "alert nurses" variable? In that case, patients would do better in the morning, regardless of the patient.

[d_tr]

Based on these graphs and the differences in outcomes they show, you are not talking about "alert vs less alert" nurses but about "nurses doing their job vs nurses basically slowly killing dozens of patients".

[anigbrowl]

Why would you assume nurses are scheduled on a 9-5 basis?

[simmerup]

Why do you think you're going to poke holes in a research article when you've clearly only just heard of the concept and havent even read the article

[tines]

If I thought I could poke holes in the research, I wouldn't be posting on HN. I'm asking questions to learn because obviously I don't understand :)

[NhanH]

Patients are assigned the time for their visits. The time itself is randomized

[gus_massa]

How many dose this treatment has? How many between them?

How many patients dropped out? (Or requested a schedule change) Do they count like live or dead?