mixmeta (version 1.2.0)

fibrinogen: Fibrinogen Studies Collaboration

Description

The Fibrinogen Studies Collaboration is a meta-analysis of individual data on 154,012 adults from 31 prospective cohort studies with information on plasma fibrinogen and major disease outcomes. The dataset reports a subset of the results of a first-stage analysis consisting of the log-hazard ratio of coronary heart disease for categories of levels of fibrinogen versus a baseline category.

Usage

fibrinogen

Format

A data frame with 31 observations on the following 15 variables:

• cohort: study ID.

• b2, b3, b4, b5: estimated log-hazard ratios for the second to fifth categories versus the baseline category.

• V_2_2, V_3_3, V_4_4, V_5_5: variances of the estimated log-hazard ratios.

• V_2_3, V_2_4, V_2_5, V_3_4, V_3_5, V_4_5: covariances of the estimated log-hazard ratios.

Details

The published analysis adopted a fixed-effects model on 10 categories of fibrinogen (Fibrinogen Studies Collaboration 2004, 2005). Here a subset of the results of the first-stage analysis is reported, namely the log-hazard ratio for 4 categories and associated (co)variance terms, ordered as the lower triangular elements of the (co)variance matrix taken by column. Details on the first-stage model and the second-stage meta-analysis are provided in White (2009) and Jackson and colleagues (2010).

Examples

# NOT RUN {
### REPRODUCE THE RESULTS IN WHITE (2009) AND JACKSON ET AL. (2010)

# INSPECT THE DATA
head(fibrinogen)

# REML MODEL
y <- as.matrix(fibrinogen[2:5])
S <- as.matrix(fibrinogen[6:15])
model <- mixmeta(y, S)

# SUMMARIZE THE RESULTS
print(summary(model), digits=3)
round(model$Psi, 3)
# }