However, I can surmise that, since the line is a probability, and that a probability is a ratio in which the denominator is the universe of possible events in question, that "normalization" for population sizes across the spectrum had to have occured.
I'd have to refer you to Dr. Emanuel or his co-author for more info.
Well, in fact I did answer your question. You asked what the implications of these [my ]questions were.
I answered:
My questions imply that the graph - while factually correct - may nonetheless be misleading.
In other words: I have difficulty deriving usable, real-world information from a graph in which the Y-axis is labelled merely "probability of receiving intervention." You can read virtually anything you want into such a lapidary label.
What does "probability of receiving intervention" actually mean?! Does it mean: "Probability that women REQUIRING or DEMANDING intervention actually GET that intervention?" Or does it mean: "Probability that a woman chosen randomly (i.e., regardless of any actual need) from the given age-cohort will receive medical attention?" Importantly: Does it take into account (in statistics: does it weight)) the fact that, in absoulte terms, the cohort of 70 to 80-year-olds is smaller than the cohort of 40 to 50-year-olds? Does it take into account that the NEEDS of an average individual in a given cohort might be greater/smaller than the needs of a randomly chosen individual from a different cohort?
Consider, for example, what it would be like if this graph were about MEN. The average man between 20 and 30 years of age hardly ever seeks medical treatment. The average man between 70 and 80 very frequently (in comparison) seeks such assistance - BUT THERE ARE A LOT FEWER OF THEM, since many of them have died off.
Further, I would expect the Y-axis to be marked with at least a "zero" and a "one."
In short: I am honestly unable to draw any practical conclusions from a graph without knowing whether it has been normalized (to reflect demographics). I bet, for example, that a 105-year-old woman has a much higher chance (probability) of receiving attention than anyone else, because she's likely in a nursing home, where she's been interviewed on "60 Minutes."
However, I can surmise that, since the line is a probability, and that a probability is a ratio in which the denominator is the universe of possible events in question, that "normalization" for population sizes across the spectrum had to have occured.
You are not surmising: You are ASSUMING.
Regards,