Table 2.
Univariate approaches for detecting CP associations
Input | Explicit test of CP association |
Allows effect heterogeneity |
Types of phenotype (such as continuous or categorical) |
Accommodates overlapping subjects |
Combine data across multiple studies |
Identify subset of associated phenotypes |
Genetic variant versus region |
Refs | |
---|---|---|---|---|---|---|---|---|---|
Fisher | P value | No | Yes | Any | No | Yes | No | Variant | 56 |
CPMA | P value | Yes | Yes | Any | No | Yes | No | Variant | 14 |
Fixed effects meta-analysis | Effect estimate | No | No | Same type; need to standardize continuous phenotypes | No | Yes | No | Variant | 54,57,58‖ |
Random effects meta-analysis | Effect estimate | No | Moderate level; not opposite effects | Same type; need to standardize continuous phenotypes | No | Yes | No | Variant | 54,57,58‖ |
Subset-based meta-analysis | Effect estimate | No | Yes | Same type; need to standardize continuous phenotypes | No; offer extension to account for some overlap | Yes | Yes | Variant | 59 |
Extensions to O’Brien | Effect estimate | No | Yes | Any | Yes; all subjects overlap* | No§ | No | Variant | 61,62 |
TATES | P value | No | Yes | Any | Yes; all subjects overlap‡ | No§ | No | Variant | 63 |
PRIMe | P value | No | Yes | Any | Yes | Yes | No | Region | 64 |
CP, cross-phenotype; CPMA, cross-phenotype meta-analysis; PRIMe, Pleiotropy Regional Identification Method; TATES, Trait-based Association Test that uses Extended Simes.
Can accommodate values missing completely at random.
Can accommodate values missing completely at random and blockwise missingness.
Can combine across multiple studies if all subjects have non-missing values for all phenotypes; TATES can accommodate situations in which a subset of studies have missing values for a subset of the phenotypes.
References are given for meta-analytical methods typically used in genome-wide association studies.