Hi Sujata,
I believe you are asking about the portion: "participants were classified into two groups once - "ever" or "never - at the start of the study" using all follow-up data available." In this sentence, "start of study" refers to the start of follow-up for this analysis. Please note, a key part of this question is to consider the total window over which exposure was assessed, relative to time 0 and E.
Hope that helps,
June
I believe you are asking about the portion: "participants were classified into two groups once - "ever" or "never - at the start of the study" using all follow-up data available." In this sentence, "start of study" refers to the start of follow-up for this analysis. Please note, a key part of this question is to consider the total window over which exposure was assessed, relative to time 0 and E.
Hope that helps,
June