• Component Description
• Eligible Sample
• Protocol and Procedure
• Quality Assurance & Quality Control
• Data Processing and Editing
• Analytic Notes
• Codebook
  • SEQN - Respondent sequence number
  • OHDEXSTS - Overall Oral Health Exam Status
  • OHDRCSTS - Recommendation Care Status Code
  • OHAREC - Overall recommendation for care
  • OHAROCDT - Decayed teeth
  • OHAROCGP - Gum disease/problem
  • OHAROCOH - Oral hygiene
  • OHAROCCI - Impression of soft tissue condition
  • OHAROCDE - Denture/Partial Denture/Plates
  • OHARNF - No significant findings
  • OHAROTH - Some other finding (specify w/referral)
  • OHAPOS - Was participant exam position recumbent

National Health and Nutrition Examination Survey

2017-2018 Data Documentation, Codebook, and Frequencies

Oral Health - Recommendation of Care (OHXREF_J)

Data File: OHXREF_J.xpt

First Published: February 2020

Last Revised: NA

Component Description

NHANES is critical for monitoring oral health status, risk indicators for disease, and access to preventive and treatment services. Oral health data from NHANES may be used for:

• Assessing the prevalence of major oral health diseases and conditions including dental caries;
• Assessing prevention and treatment efforts including the prevalence of dental sealants;
• Informing specific public health programs, policies, or initiatives;
• Monitoring the oral health status of minority/underserved populations;
• Evaluating Healthy People objectives related to oral health; and
• Supporting research activities as identified in the 2000 Surgeon General’s Report on Oral Health in the United States.

The oral health examination component provides information on a number of oral health topics including tooth count, coronal caries, root caries, dental sealants, and recommendations for dental care. These data are released in multiple data files.

This data documentation specifically provides information on the following two data files:

• Dentition Exam (OHXDEN_J) – Includes data on tooth count, coronal caries, root caries, and dental sealants.
• Recommendation of Care (OHXREF_J) – Includes data on dental care recommendations and exam position.

In addition to the oral health examination data, oral health questionnaire data are collected during the household interview. For information on these data please refer to the documentation for the Oral Health Questionnaire (OHQ) section.

Eligible Sample

All survey participants 1 year and older were eligible for the oral health examination.

Protocol and Procedure

The oral health examination was conducted by dental examiners, who were dentists (D.D.S./D.M.D.) licensed in at least one U.S. state. A health technician assisted in entering examiner observations directly into a computerized data collection system. All oral health assessments took place in a designated room at the mobile examination center (MEC) that included a portable dental chair, light, and compressed air.

For all survey participants aged 1 and older, the oral health examination began with a tooth count assessment. Next, their teeth were assessed for coronal caries, including untreated dental decay and teeth treated or extracted due to caries. For children and adolescents aged 3 to 19 years, eligible teeth were assessed for the presence of dental sealants.

In 2017-2018, the tooth count and dental sealants assessments followed the same protocols conducted in 1999-2004, and 2011-2016.

The 2017-2018 coronal caries assessment was conducted with the same protocols used in 2015-2016. These protocols are similar to the ones used in 1999-2004 and 2011-2014, with the following exception: filled surfaces were assessed by restoration type. For tooth identified as having untreated caries, additional secondary code entry was required if restoration was present on the tooth as well.

Same as in the 2015-16 cycle, for survey participants aged 18 years and older, the 2017-2018 examination included a root caries assessment. The dental examiners conducted a “whole mouth” assessment for untreated root caries and dental root restorations. Please refer to the NHANES Oral Health Examiners Manual for additional information regarding data collection protocols for the 2017-2018 oral health component.

Quality Assurance & Quality Control

The specific QA practices for the oral health examination are documented in detail in the NHANES Oral Health Examiners Manual.

All dental examiners received an initial training, which consisted of lecture, model review, practice simulations and standardization sessions. Following initial training, examiners received field training at the MEC consisting of more practice simulation, standardization, and calibration sessions with NHANES survey participants.

There are three main activities employed to facilitate the ongoing collection of quality oral health data on NHANES. To reduce data recording errors, all data are directly entered into an electronic data management system and automated data management utilities are used to check for out of range values at the time of entry. NHANES staff periodically conduct observations of the data collection to ensure that protocols are followed. Finally, the reference examiner visits each dental examiner 2-3 times a year and conducts about 20 replicate exams during each visit. Data from these replicate exams were used to produce inter-rater reliability statistics to objectively evaluate examiner agreement. Although dental examiners were aware of the inter-rater evaluations being conducted, examiners are blinded to each other’s observations. Because all inter-rater reliability statistics were calculated after the MEC evaluation visits, the findings were unavailable for real time use. However, all examiners did receive general feedback pertaining to their performance immediately following each evaluation visit by the reference examiner. An annual retraining session was conducted to reinforce existing protocols and to introduce protocol updates, if needed.

Data Processing and Editing

Frequency counts were checked and data values were reviewed prior to data release.

OHX##CSC (Coronal caries: surface condition)
This set of variables indicates surface condition identified by the coronal caries assessment for each individual tooth. The fourth and fifth digits in the variable names identify the tooth using American Dental Association’s Universal system. As was done in 2015-2016, the following new codes were also used in 2017-2018 to indicate whether untreated caries, crown, or dental restoration was present and differentiate dental restoration made with amalgams from those with other restorative dental materials:

• 0 = lingual AMALGAM restoration
• 1 = occlusal AMALGAM restoration
• 2 = facial AMALGAM restoration
• 3 = mesial AMALGAM restoration
• 4 = distal AMALGAM restoration
• 5 = lingual OTHER restoration
• 6 = occlusal OTHER restoration
• 7 = facial OTHER restoration
• 8 = mesial OTHER restoration
• 9 = distal OTHER restoration
• -1 = Crown (non-specific full-coverage restoration)
• -4 = Lingual caries
• -5 = Occlusal caries
• -6 = Facial caries
• -7 = Mesial caries
• -8 = Distal caries

Codes -4, -5, -6, -7, and -8 were used for teeth identified as affected with dental caries surface condition (i.e., OHX##CTC = “K” or “Z”). Codes 0-9 and -1 were used for teeth identified as having a restored surface (i.e., OHX##CTC = “A” or “F”). If the same tooth surface was both carious and filled, only the caries was reported in variable OHX##CSC, and the restoration would be reported in variables OHX##RTC and OHX##RSC. Similar to the codes used in the previous cycles, the values in variable OHX##CSC can be recorded as a string code, for example:"0", "13", "4,6,8", or “-5-8”.

OHX##RTC (Coronal Caries: Secondary restoration present)
This set of variables indicates secondary restoration was present and identified by the coronal caries assessment for teeth with untreated dental caries (i.e., OHX##CTC = “K” or “Z”). The following codes are used:

• A = Primary tooth with secondary dental restoration present
• F = Permanent tooth with secondary dental restoration present

If no amalgam filling or other type of restoration was present for the tooth identified with untreated coronal caries, data field for the variable OHX##RTC will be blank (missing).

OHX##RSC (Coronal Caries: Secondary restoration surface call)
This set of variables indicates the restored surface(s) and the material used that were identified by the coronal caries assessment for teeth with both caries (i.e., OHX##CTC = “K” or “Z”) and restoration (i.e., OHX##RTC = “A” or “F”) on the same surface.

• 0 = lingual AMALGAM restoration
• 1 = occlusal AMALGAM restoration
• 2 = facial AMALGAM restoration
• 3 = mesial AMALGAM restoration
• 4 = distal AMALGAM restoration
• 5 = lingual OTHER restoration
• 6 = occlusal OTHER restoration
• 7 = facial OTHER restoration
• 8 = mesial OTHER restoration
• 9 = distal OTHER restoration
• -1 = Crown (non-specific full-coverage restoration)

Similar to the codes used in OHX##CSC, these values can be recorded as a string code, for example: "0", "13", "468".

Analytic Notes

The dentition and recommendation of care data files can be linked using the unique survey participant identifier, SEQN. In addition to the examination data, self-reported data on oral health related topics are available in the Oral Health questionnaire (OHQ) section collected as part of the household interview. These data can be linked using the SEQN as well. Although the OHQ data were collected as part of the household questionnaire, if they are merged with the MEC exam data, exam sample weights should be used for the analyses. Please refer to the NHANES Analytic Guidelines and the online NHANES Tutorial for further details on the use of sample weights and other analytic issues.

If data from this release are combined with oral health data from previous data cycles for analyses, users should understand that methodological differences (in data collection) may exist among similar, earlier assessments and may bias the analysis conducted.

Codebook and Frequencies