Correlation between subjective and objective evaluation of the nasal airway. A systematic review of the highest level of evidence.

BACKGROUND There is no consensus about the value of objective measurements of nasal patency. OBJECTIVE To assess the correlation between the subjective sense of nasal patency and the outcomes found with rhinomanometry and acoustic rhinometry. TYPE OF REVIEW Structured literature search. SEARCH STRATEGY AND EVALUATION METHOD: Review of English-language articles in which correlations were sought between subjective nasal patency symptoms and objective scores as found with rhinomanometry [nasal airway resistance (NAR)] and acoustic rhinometry [minimal cross-sectional area (MCA)]. Correlations were related to unilateral or combined assessment of nasal passages and to symptomatic nasal obstruction or unobstructed nasal breathing. RESULTS Sixteen studies with a level of evidence II-a or II-b fit the inclusion criteria and were further analysed. Almost every possible combination of correlations or lack thereof in relation to the variables included was found. However, when obstructive symptoms were present, a correlation between the patency symptoms with nasal airway resistance and minimal cross-sectional area was found more often than in the absence of symptoms. In cases of bilateral assessment a correlation was found almost as often as it was not between patency symptoms and total nasal airway resistance or combined minimal cross-sectional areas, while in the limited amount of studies in which unilateral assessment was done a correlation was found each time between patency symptoms and nasal airway resistance. CONCLUSIONS The correlation between the outcomes found with rhinomanometry and acoustic rhinometry and an individual's subjective sensation of nasal patency remains uncertain. Based on this review, it seems that the chance of a correlation is greater when each nasal passage is assessed individually and when obstructive symptoms are present. There still seems to be only a limited argument for the use of rhinomanometry or acoustic rhinometry in routine rhinologic practice or for quantifying surgical results.