Figure 2.

Effect of restricting diagnostic codes to different sources of administrative data. The figure shows the classification parameter estimates for the 7 most common treatment indications based on diagnostic codes recorded within the past 365 days when restricted to diagnostic codes from either hospital discharge data, billings from all physicians, or billings from the prescribing physician only. Abbreviations: PPV, positive predictive value; NPV, negative predictive value; LR+, positive predictive value; LR−, negative predictive value