The average absolute risk difference between women taking antidepressants and nonusers was 2.87 per 1,000 person-years.
The average absolute risk difference between the most and the least deprived wards over the first 2 years of the dataset was 69.8 MI admissions per 100 000 person-years.
For lung cancer, the effect of a reduced risk estimate was not significantly different from that of an average risk estimate; however, a significant difference in ΔPR between those who received a reduced risk estimate and those who received an average risk estimate was observed for breast, prostate, and colorectal cancer (Additional file 1: Table S5).
In this analysis, we also estimated the average risk of infection as the difference in average age-specific prevalence of latent infection (i.e., the prevalence in household contacts compared with community members).
Since b is no longer constant, we use b w, a weighted average of the risk differences b i in the groups with weights depending on the within-group exposure variances (b w is also obtained by regressing the individual-level data while adjusting for group; see appendix 3): (b e - b w ) = (b c - b w ) M In the example, b w is approximately 0.296 (appendix 6).
This knowledge is mainly based on measures of average association (ie, OR) that quantify differences in average risk between exposed and unexposed groups.
Greater than 95% of respondents indicated that they (often and always responses were combined: "always") "always" recommend screening mammography to average risk women aged 50-69 years, with no differences by physician specialty (p = 0.11).
There were no significant differences in the average risk of the normal and nodule categories in spite of the fact that the 34-miRNA model and the risk algorithm were derived by training on a dataset (the training set) that did not include nodules (average risk score: normal = −4.2, nodules, −2.3, p = 0.36; Fig 3A).
The traditional goal of ecologic inference is to draw conclusions about individuals based on group-level data, or equivalently: to deduce the interior of a two-by-two table from its margins, to obtain the line in a risk diagram from the dot, or to estimate the risk difference from the ecologic data (the average risks Y i and average exposures X i ).
RD = risk difference; X i and Y i are the average exposure and average risk in group i; n i = size of group i.
