The Taste and Smell Protocol in the 2011-2014 US National Health and Nutrition Examination Survey (NHANES): Test-Retest Reliability and Validity Testing

Abstract

Introduction: The US NHANES 2011-2014 protocol includes a taste and smell questionnaire (CSQ) in home-based interviews and brief assessments in mobile exam centers. We report the short- and longer-term test-retest reliability and validity of this protocol against broader chemosensory measures.

Methods: A convenience sample of 73 adults (age=39.5±20.8 years) underwent the NHANES protocol at baseline, 2 weeks and 6 months. For taste, participants rated intensities of two tastants (1 M NaCl, 1 mM quinine) applied to the tongue tip and three tastants (1 M NaCl, 1 mM quinine, 0.32 M NaCl) sampled with the whole mouth. Smell function was assessed with a Pocket Smell Test™ (PST; eight-item odor identification test). The CSQ asked about chemosensory problems, distortions, and age-related changes. Broader baseline measurements were a 40-item olfactometer-generated identification task and additional whole-mouth taste intensities (1 M sucrose, 32 mM citric acid, 3.2 mM propylthiouracil).

Results: Intraclass correlations (ICCs) for NHANES taste measures showed moderate-to-good agreement after 2 weeks and 6 months (ICCs 0.42-0.71). Whole-mouth quinine intensity was significantly correlated with other taste intensities, supporting its utility as a marker for overall taste functioning. Olfactory classification from PSTs agreed for 98.5 % of participants across 2 weeks (κ=0.85; 95 % CI 0.71-0.99) and had good correspondence with the olfactometer task. CSQ items showed good-to-excellent agreement over 6 months (ICCs 0.66-0.90).

Conclusions: These findings further support that the NHANES chemosensory protocol has moderate-to-good test-retest reliability when administered to healthy, educated adults. Despite being a brief procedure with limited measures, the NHANES taste and smell assessments provided good information when compared to broader measures of taste and smell function.

Keywords: Bitter; Health status; NHANES; Psychophysics; Smell perception; Taste perception.

Figures

Fig. 1

Percentage agreements for individual odor identification between NHANES Pocket Tests administered at baseline and at 2-week follow-up

Fig. 2

Mean reported intensities (with error bars for SEM) on general Labeled Magnitude Scale for NHANES Pocket Smell Test odorants at baseline and at 2-week follow-up (*p<0.05)