Glucosamine is used by people with arthritis to reduce joint pain with activity. It would not be used by a group to ill to be active i.e. if you are healthy enough to worry about taking glucosamine you probably aren’t going to die this year. This result is purely selection bias obtained by data mining.
Multivariable-adjusted HR showed that the association was maintained after adjustment for age, sex, race, education, smoking status, and physical activity
Is there something in particular you saw that they did incorrectly in their analysis here?
Glucosamine is used by people with arthritis to reduce joint pain with activity. It would not be used by a group to ill to be active i.e. if you are healthy enough to worry about taking glucosamine you probably aren’t going to die this year. This result is purely selection bias obtained by data mining.
They said they controlled for that:
Is there something in particular you saw that they did incorrectly in their analysis here?
Those factors kind of cover health, but I’d guess there’s a big enough residual variation in health-consciousness to be responsible for the results.