Hi all,

I am new to the world of STATA (and fairly new to epidemiology/biostats). I have been tasked with analysing 10 years of data from a population survey looking at nutrition. Specifically I am comparing trends in consumption (volume) of sugar sweetened beverages over 10 years across different subgroups of our survey population. Was progressing okay until I discovered our weighting system involves non-integers (raked weighting). I am unable to use fweight or pweight with non integer weights. aweight does not appear to be the correct weight to use for survey data, and gives incorrect output (I think). This leaves me with iweight, which appears to generate correct weighted results for frequency tables (when compared to SPSS output). Reading around the issue though, iweight does not seem designed for this process, and is not going to be suitable for use with summary statistics.

How should I approach survey data with non integer weights? I cant find a clear answer on this searching forums.

(I will need to calculate mean consumption for each year for each subgroup, assess trends over time, and use test of trend to ensure statistical significance. I have around 150 subgroups)

Thanks in advance