Figure 1.

Distribution of spirometry-derived chronic obstructive pulmonary disease (COPD) prevalence rates in five sub-Saharan Africa (sSA) studies. This figure reports the mean age- and spirometry-derived COPD prevalence rates in five population-based studies in sSA identified in a systematic review covering the period from 1990 to 2014 (6). Information about the study sample and design of each study is summarized in the review. The size of the bubble corresponds to the relative sample size of the study. The year reported for each study is the time (or midpoint) of the study, not the year of publication.