Table 1 Sampling designs and analytical methods for QT association analysis
Sampling designs | Method of analysis | Software | |
|---|---|---|---|
| Â | Common variant | Rare variant score | Â |
1. Entire cohort (100%) 2. 50% simple random sample 3. All observations in each of 25% tails of the QT distribution 4. All observations in each of 20% tails and central 10% of QT distribution 5. 50% sample by distance from the median of the QT distribution | a. Linear regression of QT on genotype b. Logistic regression of genotype with QT as covariate | c. Linear regression of QT on rare allele count d. Poisson regression of rare allele count with QT as covariate | Designs 1–5: generalized linear regression (glm) function in R for fitting all models Design 5 for methods a and c: svyglm function in R with inverse probability weights |