4 ms·

Anything that is less than double-blind is essentially a well documented hunch. In some situations this enough to merit action. This study is interesting enou

by htag 3y ago

Anything that is less than double-blind is essentially a well documented hunch. In some situations this enough to merit action. This study is interesting enough to merit more science to build stronger evidence. Merits of this study: * It was large, twelve years and over 200,000 participants. * The impact was dose responsive. People that reported talking longer on the phone had greater chances of hypertension. * The impact is large enough to cause concern. * In the published article, a mechanism of action was purposed (RF-EMF), and other studies related to this mechanism were cited. * It fits the expected amount of 'controlling for' third variables you would expect, even if we cannot control for everything. Weaknesses of this study: * Mobile usage was self reported. Using empirical data such as cellphone bills or data from cellphone would have been much more accurate. There could be a bias where those with higher blood pressure perceive themselves as talking on mobile more frequently. * There was no determination of the nature of the calls. Personally, my blood pressure feels very different when I talk to family for 30 minutes than if I'm talking to Comcast for 30 minutes. * About 3/5 of the study participants dropped out. We'd expect lots of dropouts to occur with such a long study, but it could skew the data if dropouts had some statistical significance on measured values and weren't random. Dropouts are almost never random. * The article admits those with mobile phone usage seem to be at a higher natural disposition for hypertension. More likely to smoke, many other high variables. It seems plausible that some other risk factors were associated with that cluster that did not get accounted for. * No direct measurement of the purposed mechanism of action was performed.

Jeff_Brown 3y ago
> Anything that is less than double-blind is essentially a well documented hunch. Not true! Economists have devoted person-millenia developing the theory of instrumental variables, which lets you extract causal relationships from historical non-experimental data. That said, it's damn hard to find a good instrument. Many economists use it badly, and most doctors don't even know the theory.
- htag 3y ago
  I have my doubts about IVs in practice, but I agree they theoretically are an acceptable substitute. The problem is we conduct science on systems we don't fully understand. Because we don't fully understand it, it's easy to miss important information we didn't know is important. The double blind with random selection allows us to control for all important information, determine causation, and is the best known method for controlling for bias. We don't have to worry about missing important variables because the nature of random selection means those variables are randomly distributed.
  - Jeff_Brown 3y ago
    When possible, experiments are better, yes. But that should not cause us to give up hope for causal information in areas where experiments are impossible.
- monkeyjoe 3y ago
  Even subject level fixed effects would have made this a much better study. Doesn’t need to go all the way to IV to be a thoughtful design.
rcme 3y ago
They proposed RF-EMF as the mechanism of action, but they didn't provide any evidence that RF-EMF was the cause of the hypertension.
- cpncrunch 3y ago
  Yeah, it seems highly unlikely. Having to talk a lot on the phone gives me stress. It's odd they don't even mention the most probably reason for their finding, and invent some unproven theory about emf affecting blood pressure. The only study I can find is this: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(98)24025-6/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6... It's a 7 person study, and it looks like they didn't correct for multiple comparisons. i.e. nothing to see here.
- htag 3y ago
  The evidence is that increased mobile use means increased RF-EMF dosage. It's not solid, but it's not bad for a survey.
  - rcme 3y ago
    Sure, but, like the drop outs, all human behavior is correlated with a million other things. Myself and others have mentioned stress as a possible factor, but there are likely random things you wouldn't even think of like: people who use the phone more are more likely to talk to telemarketers, and talking to telemarketers is correlated with lower intelligence, and lower intelligence is correlated with eating more salt. I'm not suggesting that as a possible cause, just illustrating how complicated the true causal relationship could be. I think it's really a stretch to treat this study as establishing a causal relationship. There are also some open questions like why other types of phone usage don't seem to trigger this effect (the author mentions other studies purely on smartphone use have been inconsistent). If the authors really believe RF-EMF can cause hypertension, then this study is a fine first step. But they really should find a way to test the mechanism of action before saying they've found a causal relationship.
    - htag 3y ago
nottorp 3y ago
> There was no determination of the nature of the calls. Personally, my blood pressure feels very different when I talk to family for 30 minutes than if I'm talking to Comcast for 30 minutes. In my opinion that's the explanation. Even if not considering the extremes you mentioned, the more you're interrupted the less relaxed you are. The metric here is minutes talked but they're probably linear with the number of unexpected calls.
9991 3y ago
> People that reported talking longer on the phone had greater chances of hypertension. The study depended on self-report? The solution is obviously to stop reporting that one talks on the phone.
deleted 3y ago
[deleted]

by htag 3y ago

Jeff_Brown 3y ago

> Anything that is less than double-blind is essentially a well documented hunch. Not true! Economists have devoted person-millenia developing the theory of instrumental variables, which lets you extract causal relationships from historical non-experimental data. That said, it's damn hard to find a good instrument. Many economists use it badly, and most doctors don't even know the theory.

htag 3y ago
I have my doubts about IVs in practice, but I agree they theoretically are an acceptable substitute. The problem is we conduct science on systems we don't fully understand. Because we don't fully understand it, it's easy to miss important information we didn't know is important. The double blind with random selection allows us to control for all important information, determine causation, and is the best known method for controlling for bias. We don't have to worry about missing important variables because the nature of random selection means those variables are randomly distributed.
- Jeff_Brown 3y ago
  When possible, experiments are better, yes. But that should not cause us to give up hope for causal information in areas where experiments are impossible.
monkeyjoe 3y ago
Even subject level fixed effects would have made this a much better study. Doesn’t need to go all the way to IV to be a thoughtful design.

rcme 3y ago

They proposed RF-EMF as the mechanism of action, but they didn't provide any evidence that RF-EMF was the cause of the hypertension.

cpncrunch 3y ago
Yeah, it seems highly unlikely. Having to talk a lot on the phone gives me stress. It's odd they don't even mention the most probably reason for their finding, and invent some unproven theory about emf affecting blood pressure. The only study I can find is this: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(98)24025-6/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6... It's a 7 person study, and it looks like they didn't correct for multiple comparisons. i.e. nothing to see here.
htag 3y ago
The evidence is that increased mobile use means increased RF-EMF dosage. It's not solid, but it's not bad for a survey.
- rcme 3y ago
  Sure, but, like the drop outs, all human behavior is correlated with a million other things. Myself and others have mentioned stress as a possible factor, but there are likely random things you wouldn't even think of like: people who use the phone more are more likely to talk to telemarketers, and talking to telemarketers is correlated with lower intelligence, and lower intelligence is correlated with eating more salt. I'm not suggesting that as a possible cause, just illustrating how complicated the true causal relationship could be. I think it's really a stretch to treat this study as establishing a causal relationship. There are also some open questions like why other types of phone usage don't seem to trigger this effect (the author mentions other studies purely on smartphone use have been inconsistent). If the authors really believe RF-EMF can cause hypertension, then this study is a fine first step. But they really should find a way to test the mechanism of action before saying they've found a causal relationship.
  - htag 3y ago

nottorp 3y ago

> There was no determination of the nature of the calls. Personally, my blood pressure feels very different when I talk to family for 30 minutes than if I'm talking to Comcast for 30 minutes. In my opinion that's the explanation. Even if not considering the extremes you mentioned, the more you're interrupted the less relaxed you are. The metric here is minutes talked but they're probably linear with the number of unexpected calls.

9991 3y ago

> People that reported talking longer on the phone had greater chances of hypertension. The study depended on self-report? The solution is obviously to stop reporting that one talks on the phone.

deleted 3y ago

[deleted]