Reference values | Mean (cmH_{2}O)* | SEE LLN=mean−(SEE×1.645) |

Male SNIP | (−0.42 × age) + 126.8 | SEE=23.8 |

Female SNIP | (−0 22 × age) + 94.9 | SEE=17.1 |

Mean reference values and LLN for SNIP in men and women using the regression equations. Men: y=−0.42 age + 126.8, SEE=23.8; women: y=−0 22 age + 94.9, SEE=17.1, as determined by Uldry and Fitting.135 The LLN is determined by subtracting the SEE × 1.645.

*To convert cmH

_{2}O to kPa multiply by 0.0980665.LLN, lower limit of normal; SEE, standard error of estimate; SNIP, sniff nasal inspiratory pressure.