Edit: I've got this wrong - please see biophile's post, below, for a full explanation of this issue Please labour away Sam. I'm keen to understand this paper. I can't quite follow your post though, Sam, unless you didn't quite follow my last post! The (small) n figure of 141, for APT, denotes how many participants that they managed to get follow-up data on, for APT. But at the end of the original PACE Trial, they had 159 participants in the APT group. (See the numbers at the top of Table 1 in this paper, for the original numbers in each therapy group, in the PACE Trial paper.) In Table 4, the first figures in the APT column are: 28 (18). If we use the numbers of participants for the original PACE Trial paper, then is all adds up: 18% of 159 is 28.62. (159 being the original number in the APT group in the PACE Trial paper.) So I think they have just made the mistake of using the number of participants from the original PACE Trial paper to calculate the percentages. This works out for all the other figures in Table 4 that I've calculated (i haven't tested them all.) So I think they've just made this simple error (that just happens to make their percentages look more favourable.) It seems almost impossible to discuss this paper, because it's so complex, so if that doesn't make sense, then please ask again Sam.