Operating Characteristic Curves for the two LQAS classifications. The curves plot the probability of site being classified as ‘high data quality’ based on the LQAS procedure for a given level of concordance between treatment cards and the register. Figure 1a is the plot for the 85%/95% classification. Figure 1b is the plot for the 89%/99% classification, superimposed on top of the 85%/95% classification. Each point represents a clinic, plotted at their true level of concordance between the treatment cards and register based on exhaustive review at the site. Circles indicate sites that are classified as ‘low data quality’ based on the LQAS classification. Triangles indicate sites that are classified as ‘high data quality’.