An acceptable spirogram should not be discarded even if it cannot be reproduced. Perhaps 2 more spirograms can be gotten on another day. Up to 8 efforts may be performed at one time in order to meet acceptability and reproducibility criteria. Beyond 8 efforts, fatigue may play a role in the results, and additional efforts are not warranted. When reporting the actual values obtained from spirometry, the highest FEV1 and FVC should be reported and may be from different efforts. By contrast, FEF 25-75, flow volume, and volume time curves should be reported from the best test curve. This is defined as the acceptable curve with the largest sum of FVC and FEV1.