RVD2 has three levels of sampling.
This was repeated for five choices of sample sizes.
This method allows the researcher to balance the issues of sample size and data-accuracy and to explore this balance from three different levels of certainty.
Effect size as a function of sample size was funnel shaped; there were no obvious gaps in distributions at any one sample size, and variation in effect size was characteristically greater at low sample size.
As would be expected in a population-based analysis of diabetes complications, there were substantial variations in age, diabetes duration, and sample size among the five levels of disease severity.
I might feel a million miles away from the world of sample sizes, but I'm not.
Under each of the three scenarios, four different network patterns, seven different numbers of studies per comparison, and three different study-level sample sizes were used to simulate arm-level data.
Figure 2 shows the adjusted mean CIMT across these four groups of equal sample size at the mean levels of the covariates (age, sex, education, and income).
However, using the estimated error variances of the change in outcomes and considering a balanced design with two levels of LH score and two treatment groups, a sample size of (4 × 9 =) 36 is sufficient to detect a difference in therapy means between LH groups of 52.9, 8.6 and 16.7 for VAS, RMQ and PRI respectively with 80% power.
The first two were judged on sample size assessment; the third by looking at the gender of all 7,656 members.
Before doing so, we re-grouped the six levels of the age categorical variable into four levels only, to homogenize the sample size: extreme data with the smallest sample sizes were grouped with their next level.
