Figure.

Prospective studies of Chlamydia pneumoniae IgG titres and coronary heart disease. Black squares indicate the odds ratio in each study, with the square size proportional to the number of cases and horizontal lines representing 99% confidence intervals. The combined odds ratio and its 95% confidence interval are indicated by a diamond. Degree of adjustment for possible confounders is denoted as +++ for age, sex, smoking, and some other classic vascular risk factors, and ++++ for these plus markers of socioeconomic status (or studies done in socially homogeneous groups). Some studies did not provide separate results for non-fatal myocardial infarction or death from coronary heart disease (instead reporting coronary heart disease results combined with those for stroke¹²,¹⁴ or angina¹⁹,²⁰). These studies, however, comprised only about 10% of the total cases in this meta-analysis, and most of the cases in these studies had major coronary events