[Stability of lung function parameters: spirometry, body plethysmography and mouth occlusion pressure (p0.1)].

Spirometric, bodyplethysmographic and mouth occlusion results of 9 healthy probands were measured 9 - 11 times over a total of 28 - 39 days. Interindividual predicted values based on large studies show SDs of +/- 20 %, which is not acceptable for the judgement of individual values. Individual values are much less scattered (SD +/- 10 %). Each test person showed a differing individual range of 75 - 140 %. Functional basic facts can be derived from the different levels of individual values. Early changes in the individual range are of special interest. For the evaluation of individual results the earliest possible basic values are of importance.