Laboratory 1 (n=218) | Laboratory 2 (n=131) | Laboratory 3/4† (n=39) | p value‡ | |
---|---|---|---|---|

A minus sign indicates higher mean laboratory values, absence of a minus sign indicates higher general practice values. | ||||

*Combined results of pre-bronchodilator and post-bronchodilator values | ||||

†Because of the small number of study subjects (n=7) the results of laboratory 4 have been added to the results of laboratory 3, the laboratory with the next smallest number of subjects. | ||||

‡ANOVA test for difference between laboratories. | ||||

First year | ||||

ΔFEV_{1}*(l) | 0.078 (0.20) | 0.053 (0.21) | 0.078 (0.22) | 0.286 |

ΔFVC*(l) | 0.079 (0.36) | 0.095 (0.44) | 0.046 (0.39) | 0.636 |

Second year | ||||

ΔFEV_{1}*(l) | 0.082 (0.21) | 0.016 (0.19) | 0.036 (0.13) | <0.001 |

ΔFVC*(l) | 0.086 (0.36) | 0.095 (0.42) | −0.016 (0.25) | 0.115 |