Table 1.

Available methods for quantitative synthesis in prognostic factor research

Available data		Estimate of interest	Possible methods for evidence synthesis
AD	Baseline characteristics	Linear FOA	Meta-regression [34]
	Similarly adjusted FOAs	Linear FOA	Univariate meta-analysis [19], multivariate meta-analysis [20, 33, 57]
		Non-linear FOA	Univariate meta-analysis [36, 37], multivariate meta-analysis [35]
	Not similarly adjusted FOAs	Linear FOA	Multivariate meta-analysis [33, 56, 57]
IPD		Linear FOA	One-stage meta-analysis [34, 38], two-stage meta-analysis [38], multivariate
			meta-analysis [38, 56], graphical meta-analysis [98]
		Non-linear FOA	One-stage meta-analysis [34, 41], two-stage meta-analysis [37, 41], multivariate
			meta-analysis [43]
IPD + AD	Baseline characteristiscs	Linear FOA	Hierarchical-related regression [34]
		Non-linear FOA	Hierarchical-related regression [34]
	Similarly adjusted FOAs	Linear FOA	Two-stage meta-analysis, hierarchical-related regression [49]
		Non-linear FOA	Two-stage meta-analysis [37], hierarchical-related regression [34]
	Not similarly adjusted FOAs	Linear FOA	Multivariate meta-analysis [51, 56], adaptation method [53, 54]

FOA factor-outcome association