The reproducibility of nasal patency measurements was assessed by acoustic
rhinometry and active rhinomanometry using previously described Toronto met
hodologies. Sh subjects with normal upper airways were tested with both pro
cedures on sh separate occasions within a 2-month period. Topical decongest
ant was applied to minimize the effects of mucosal variarion on the nasal a
irway. The mean coefficients of variation (mean +/- s.d. %) over time of th
e measurements were 8.1 +/- 4.1 and 9.7 +/- 5.2 for minimal unilateral cros
s-sectional area and 4.8 +/- 1.8 and 5.5 +/- 3.5 for nasal volume (0-5 cm)
of the right and left sides, respectively. For active rhinomanometry, the m
ean coefficients of variation (mean +/- s.d.; %) over rime of the measureme
nts were 15.9 +/- 7.3, 12.9 +/- 4.6, and 8.5 +/- 2.8 for right, left and co
mbined nasal airflow resistance. The intraclass correlation coefficient was
0.76, 0.70, and 0.96 for right, left, and combined nasal resistance, 0.91
and 0.87 for right and left minimal cross sectional area, and 0.86 and 0.69
for right and left nasal volumes, respectively, also confirming a high lev
el of reproducibility for both methods. In conclusion, performed by nit exp
erienced operator under controlled circumstances, the reproducibility of bo
th methods of nasal patency assessment compared favourably with many widely
accepted clinical rests.