Funnel plot for percentage of patients thrombolysed within 30 minutes of arriving in hospital (DTN 30). Data abstracted from the MINAP Third Public Report. DTN = door to needle time, LCL = lower control limit, UCL = upper control limit, target = National Service Framework for coronary heart disease goal of 75%. Funnel plot with control limits for both mean performance and target performance. In this case the number of hospitals identified is similar.