3 ms·

> There were a dozen covariates controlled in the present study (age, gender, race, household size, smoking, body mass index, MET-minutes of total physical acti

> There were a dozen covariates controlled in the present study (age, gender, race, household size, smoking, body mass index, MET-minutes of total physical activity, alcohol use, grams of protein consumed per kilogram of body weight, percentage of energy derived from dietary fat, grams of dietary fiber consumed per 1000 kilocalories, and percentage of total energy derived from saturated fat.

andreilys 7y ago
There are of course other confounding variables that this study likely does not take into account (whether because they can’t measure it, or they chose not to include it)
dtwest 7y ago
How would one handle that many factors? I am very curious what the techniques for doing so would be. I'm no expert but my initial reaction would be that you need more than 5834 adults in a study that controls for all of those factors. We don't really know how household size, for example, would affect the results, so wouldn't you need a bunch of test data to analyze all of the combinations? Or did they only study people who are the same in most of them? (i.e. 45, male, with a household size of 4, nonsmoking, etc...) Would love to hear from someone more informed on this than myself.
- iron0013 7y ago
  It depends on the effect sizes, but in most contexts 5k participants is considered a very sufficient sample. You don’t need millions of participants to study things like this.
wahern 7y ago
The actual paper seems inconsistent and contradictory. For example, from Section 4: > Fourth, adjusting for differences in demographic, lifestyle, and dietary covariates has little influence on the relationship between milk fat intake and biological aging. Fifth, there is no relationship between milk fat intake and telomere length among adults who consumed low levels of total saturated fat (tertile 1), but it is strong among adults who consumed moderate or high levels of total saturated fat. WTF? Am I misunderstanding something? Source: https://new.hindawi.com/journals/omcl/2019/1574021/ https://new.hindawi.com/journals/omcl/2019/1574021/
- iron0013 7y ago
  I can’t speak for this specific study, but in general that sounds like a statistical interaction, which is very common in statistical modeling.

andreilys 7y ago

There are of course other confounding variables that this study likely does not take into account (whether because they can’t measure it, or they chose not to include it)

dtwest 7y ago

How would one handle that many factors? I am very curious what the techniques for doing so would be. I'm no expert but my initial reaction would be that you need more than 5834 adults in a study that controls for all of those factors. We don't really know how household size, for example, would affect the results, so wouldn't you need a bunch of test data to analyze all of the combinations? Or did they only study people who are the same in most of them? (i.e. 45, male, with a household size of 4, nonsmoking, etc...) Would love to hear from someone more informed on this than myself.

iron0013 7y ago
It depends on the effect sizes, but in most contexts 5k participants is considered a very sufficient sample. You don’t need millions of participants to study things like this.

wahern 7y ago

The actual paper seems inconsistent and contradictory. For example, from Section 4: > Fourth, adjusting for differences in demographic, lifestyle, and dietary covariates has little influence on the relationship between milk fat intake and biological aging. Fifth, there is no relationship between milk fat intake and telomere length among adults who consumed low levels of total saturated fat (tertile 1), but it is strong among adults who consumed moderate or high levels of total saturated fat. WTF? Am I misunderstanding something? Source: https://new.hindawi.com/journals/omcl/2019/1574021/ https://new.hindawi.com/journals/omcl/2019/1574021/

iron0013 7y ago
I can’t speak for this specific study, but in general that sounds like a statistical interaction, which is very common in statistical modeling.