National Health and Nutrition Examination Survey

The Taste & Smell Questionnaire Section (variable name prefix CSQ) collected interview data on taste and smell ability and related health conditions. The senses of taste and smell mediate all the body’s food intake. These two senses work together to provide food flavor perception and palatability. Self-reported data on taste and smell may therefore be relevant to the analysis of NHANES nutritional, blood pressure, obesity, and health measures data. Also, the CSQ questionnaire was designed to provide data to support the Healthy People 2020 objectives for taste and smell disorders (Healthy People, 2020).

In the healthy normal population, genetic and functional variation in taste and smell ability may help explain part of individual differences in food preferences and consumption. This could assist in our understanding of diet-related health conditions. There are also age-related changes in smell and flavor perception that may affect food palatability and nutrient intake. Metabolic rate and energy intake are known to decrease with age, so food selection in older persons can be important for maintaining nutrition and energy balance. With age, some persons may consume more in response to a reduced ability to smell, while others may consume less.

Prior national-level U.S. data on taste and smell includes the 1994 National Health Interview Survey– Disability Supplement (NHIS, 1994), a population-based questionnaire survey which estimated that among U.S. adults, there was a 1.4% prevalence of chronic smell problems and a 0.6% prevalence of chronic taste problems. With combined data, 1.65% of adults reported either a chronic smell or a chronic taste problem. In the survey, prevalence rates increased exponentially with age and almost 40% of those with a self-reported smell or taste problem were 65 years of age or older (Hoffman et al., 1998). Another national level questionnaire survey of olfactory dysfunction has recently been reported (Lee et al, 2013).

The NHANES 2011-12 household interview taste and smell questionnaire collected data on self-reported taste and smell ability, selected symptoms of and medical treatment for taste and smell disorders, and data on conditions that may represent risk factors for taste and smell disorders. These questionnaire items may be helpful to describe self-reported variation in taste and smell ability, and to estimate the prevalence of self-reported medical provider diagnosed smell and taste disorders among U.S. adults.

Adults of both genders ages 40+ years were eligible to participate. There were no exclusions for the CSQ taste & smell questionnaire.

These questions were asked, in the home, by trained interviewers using the Computer-Assisted Personal Interviewing (CAPI) system.

The CAPI system is programmed with built-in consistency checks to reduce data entry errors. CAPI also uses online help screens to assist interviewers in defining key terms used in the questionnaire.

The 2011–12 NHANES taste and smell questionnaire data was verified against the main data collection file prior to public release.

These data were collected as a part of the NHANES Household Questionnaire Interview. For data analysis, NHANES Household Interview weights should be used if only questionnaire data is being studied. However, if CSQ questionnaire data is merged with MEC examination or laboratory data, then NHANES MEC examination weights should be used for the analyses (or if applicable, subsample laboratory weights). Please refer to the NHANES Analytic Guidelines and the on-line NHANES Tutorial for further details on the use of sample weights and other analytic issues.

The CSQ questionnaire was specially developed for NHANES use and had not been previously used elsewhere. Despite prior cognitive testing of the instrument, when the CSQ questionnaire was fielded, one question did not perform as intended. CSQ030 was intended to capture a history of an altered, typically unpleasant perception of smell in the presence of an ordinary odor (parosmia). In the field most participants who answered “yes” to this question did not believe that they had any problem with their ability to smell. However, CSQ030 was retained in the public data release because of the possibility that it might have some analytic use where there was other questionnaire or examination data to suggest an abnormality of smell.

Decreased taste and smell ability may be transient (for example, from a recent temporary illness) or chronic. The variable CSQ070 captures this dimension for abnormalities of smell. Duration of taste or smell symptoms is captured by the variables CSQ140 and CSQ060, respectively. Taste and smell ability may be adversely affected by a number of chronic health conditions and by the side effects of prescription medications. A recently published community study indicates that smoking may also adversely affect the ability to smell and taste (Vennemann et al., 2008).

A number of NHANES 2011-12 datasets may be pertinent to the analysis of taste and smell data. These include NHANES datasets on medical conditions (MCQ, KIQ, DIQ, BPQ); blood sugar (BIOPRO, GHB); blood pressure (BPX); body weight (BMQ, WHQ); diet and nutrition (DTQ, DRXDOC, DSQDOC, DBQ); smoking (SMQ, COTNAL); osteoporosis (OSQ, DXX); oral health (OHXDEN, OHXPER); and prescription medication use (RXQ_RX).

The variables CSQ200 through CSQ260 identify a history of some co-morbid conditions not captured in other NHANES questionnaires that could potentially affect taste and smell. These include the history of a recent prolonged head cold or flu; persistent dry mouth; chronic nasal congestion resulting from allergies; recurrent sinusitis, a history of tonsillectomy or of wisdom teeth extraction; and loss of consciousness or nasal fracture due to head injury. Also the AUQ_G Household Interview Audiometry questionnaire collected 2 additional questions: a history of repeated ear infections (AUQ136) and a history of ear tube placement (AUQ138).