Revisions Made to IPUMS NHIS
Below is a list of significant changes made to the IPUMS NHIS data, documentation, and extract system.
- May 2016
- March 2016
- September 2015
- July 2015
- June 2015
- April 2015
- March 2015
- October 2014
- July 2014
- June 2014
March 30, 2016.
Changes to the data since September 14, 2015. Nearly 1,000 variables from historical NHIS supplements are now available through the IHIS database.
- Nearly 1,000 variables covering the Alcohol Use, Occupational Health, Mental Health, Family Resources, Adult Supplemental Items, and Health Insurance Exchange supplements are now available from the IHIS online database.
March 30, 2016.
Changes to the data since September 14, 2015. Nearly 1,000 variables from historical NHIS supplements are now available through the IHIS database.
- Nearly 1,000 variables covering the Alcohol Use, Occupational Health, Mental Health, Family Resources, Adult Supplemental Items, and Health Insurance Exchange supplements are now available from the IHIS online database.
- This release also incorporates spouse person number (SPLOC) and method for assigning spouse person number (SPRULE), the first of a set of expected Family Pointer variables that define family relationships between household members in a comparable way across the 1963-present time period.
- IHIS updated the variables IRBODY1 through IRBODY4 in 2007 to correct an error. Previously, nose injuries were being incorrectly recoded as "head (not face)" injuries.
- IHIS corrected source data for the variable VISITYRNO for 2011-2014. VISITYRNO was incorrectly using source information for the number of home visits (rather than the number of office visits) for sample adults, although it was using the correct information for sample children and for other sample years. It has been updated to refer to the number of office visits in 2011-2014 for both sample adults and sample children.
- IHIS corrected the formula used to calculate the variables POVIMPHHS1 through POVIMPHHS5 for the 2011-2014 samples. IHIS staff create POVIMPHHS1-POVIMPHHS5 using FAMSIZE and INCIMPPOINT1 through INCIMPPOINT5 to generate poverty ratios using the imputed income data that mimic the poverty ratios created by NCHS using unimputed income data. In the prior release, IHIS staff mistakenly used the base and increment values for calculating poverty thresholds from the current rather than the previous year. Base and increment values are set by the U.S. Department of Health and Human Services.
September 23, 2015.
Changes to the data since July 20, 2015. Newly released 2014 imputed income files and updated 2014 injury-level files now included in IHIS database. NHIS corrected sample child birthweights for 2004-2010 samples integrated.
- Imputed income variables from the 2014 NHIS are now harmonized into IHIS. 2014 survey text is now available, allowing users to easily access the original survey questions associated with integrated IHIS variables.This release also includes over 500 variables from historic NHIS supplements including immunizations, arthritis, assisitive devices, home care, and more.
- In September of 2015 NCHS re-released the 2014 injury and poisoning episode file. This re-released file included variables created through medical coding, including the ICD-9 codes for conditions associated with each injury/poisoning record, and external cause codes (or E-codes). IHIS now includes these variables as well as the associated person-level variables. There were additional changes in frequency distribution between the original and re-released injury/poisoning episode-level files; these differences also affect the person-level variables created from the episode-level data. These changes are not systematically associated with a single variable or group of variables. Users who created an extract using 2014 person-level or episode-level injury data prior to September 23, 2015 should be advised that the data have changed and the current IHIS version reflects the most recent NCHS release of the injury/poisoning episode file released on September 9, 2015.
- This release also incorporates the re-released NCHS files with corrected child birth weights for the 2004-2010 sample child files. The originally released 2004-2010 sample child birth weight values contained few high birth weight children and an elevated number of very low birth weight children. After re-examining the raw data, NHIS staff identified an error in processing the raw two-digit data for pounds, where values were accidentally collapsed to a single digit and obscured high birth weight children; these errors were transferred when creating the parallel variable that reports birth weight in grams. Additionally, the top and bottom codes for persons reporting child birth weight in grams misclassified children with birthweights over 5485 grams into a missing category. Ounce data were not originally incorrect and are therefore not affected. IHIS integrated these corrected birth weight files and updated the affected variables BWGTLB and BWGTGRAM, as well as offering a new summary variable BWGTTOTOZ, which reports birth weight in total ounces. Users interested in comparing the original birthweight files should contact IHIS user support to obtain the previous, incorrect values for these years. Original NCHS documentation on the corrected birth weight files is available here.
- IHIS updated the variable MARST in 2014 to disaggregate the persons who reported being "Married" into "Married-spouse present" and "Married-spouse absent". This change only offers additional detail and it does not change the marital status of persons.
- Four variables providing information on surgical insurance coverage (SURGBLUE, SURGPREP, SURGPRIV, and SURGUNKN) were updated to disaggregate persons not in universe from no responses; this involved a change in codes associated with each response category. The variable SURGBLUE74 was eliminated and combined with SURGBLUE.
- IHIS corrected source data for the variable HIPUBCOVE for all years. NCHS creates an alternate version of insurance coverage variables which are back-edited based on verbatim responses to health insurance plans named by respondents. Previously, HIPUBCOVE mistakenly duplicated the directly reported information about different types of public coverage available in HIPUBCOV. HIPUBCOVE now correctly summarizes information from the NCHS-edited versions of variables that report if an individual is covered by any of several public programs. Detailed coverage of the NCHS back editing process for health insurance variables can be found in the IHIS Summary and Key Insurance Variables user note.
July 20, 2015.
Newly released 2014 NHIS data now integrated into IHIS database.
- IHIS now offers most variables from the 2014 NHIS, including measures of health care access, health behaviors, disability and conditions, core demographics, injury and poisoning episodes, and socioeconomic indicators.
- IHIS changed the codes and updated the value labels for the variable LVISOTHTYPE to account for new response categories included in 2014. The underlying frequencies remain the same for all previously available years; however the numerical codes associated with response categories have changed slightly.
June 29, 2015.
Changes to the data since April 28, 2015 and updated NHIS-NDI linked mortality data, harmonized occupation and industry variables, 1997-1999 injury and poisoning records, and historical supplements on Hearing, Vision, Asthma, Unintentional Injuries, and Pregnancy and Smoking.
- IHIS now includes the updated mortality files, with data from 1986-2009. Variables from these files allow users to link 1986-2009 IHIS variables with death certificate information from the National Death Index through December 2011, enabling statistical analyses of the relationship between mortality and the rich array of socio-demographic characteristics, health factors, and health care access information available in the NHIS data.
- IHIS has created harmonized industry and occupation variables for 1969 to the present to allow for comparisons of consistent categories time. The original detailed industry and occupation codes are also now available in the same variables over time (IND and OCC), making it easier for users to include all relevant information in their extracts. For more information, please see the IHIS user note on how the industry and occupation variables were constructed.
- This release also integrates the injury and poisoning episode records for 1997-1999. These variables were originally released by the NHIS as two separate files, but IHIS has combined the two files into a single record type to improve ease of use and comparability. See our Injury and Poisoning Supplement User Note for more details on this harmonization or use the variable IRPOISYN to identify records that were originally on the poisoning file in 1997-1999.
- Additionally the release adds historical supplements on the topics of hearing, vision, asthma, unintentional injuries, as well as pregnancy and smoking.
IHIS is also debuting its data brief series, a set of concise research reports that highlight unique aspects of the IHIS database and interesting research topics that can be investigated using the data. Brief 01: Multigenerational Families and Food Insecurity in the United States, 1998-2013.
- IHIS staff updated the codes for the variable RELATE in 1969-1996 to provide more detailed information available in the original data. RELATE reports the relationship of each person in the household to the household reference person, or householder. From 1969-1981 there are differentiated codes for a woman whose husband lives at home and is (presumably) defined as the householder but is not included in the survey because he serves in the Armed Forces (coded in the IHIS as RELATE = 22), and a woman whose husband lives at home and is (presumably) defined as the householder and is NOT in the armed forces and should be included in the survey (coded in the IHIS as RELATE = 21). For the 1982-1996 surveys this gendered language is dropped and the labels are updated to "other spouse IN Armed Forces and living at home" (RELATE = 22) or "other spouse NOT in Armed Forces and living at home" (RELATE = 21). These updated codes can be combined, where all responses that begin with a "2" can be compiled into a single, generic "spouse" category.
- The variable IRHOSP was eliminated after being merged with the variable IRMEDHOSP as they contained parallel information available in different years. The frequencies, codes, and meaning of the variable remain the same.
- The variable NHISIID was updated to be 19 columns wide. This was necessary so the unique identifier could include IRPOISYN in 1997-1999, which distinguishes injury episodes from poisoning episodes in the original NHIS files. IRPOISYN is also necessary to identify if the value in IRINJNUM is the nth injury record or the nth poisoning record of the person in the 1997-1999 samples.
- The variable POISCENHEAR was corrected by removing children under age 10 from the universe into a separate variable for children, POISCENHEARCH. Children under age 10 were previously included with sample adults, leading IHIS software to inappropriately assign the weight PERWEIGHT to sample adults. POISCENHEAR now has a correct weight of SAMPWEIGHT and POISCENHEARCH has a correct weight of PERWEIGHT.
- The IHIS now includes imputed income data for 1990-1996. While these differ in structure from the 1997-forward imputed income files, they can be used to fill in missing income data for all persons in the 1990-1996 samples. Over 2000 variables from the complementary and alternative medicine (CAM) supplements for sample adults and sample children have been fully integrated into the IHIS data for the 2012 sample. A change in the structure of the CAM questionnaire makes it difficult to compare original NHIS CAM data from 2012 with previous samples; the newly released IHIS data include the original variables released by NHIS in 2012 as well as variables constructed through special programming that are comparable to CAM variables released by the NHIS in previous years to allow for easier analysis of these variables over time. The release also includes a series of variables rom the 2002 survey on barriers to community participation. Finally, historic child development and child medication variables from the 1981 child health supplement are now available through the IHIS.
- IHIS briefly offered updated NHIS-NDI linked mortality files for the years 1986-2009. These data were from the National Center for Health Statistics files released in February 2015. However, on April 28, 2015 NCHS re-released the files citing a problem with the public use files originally offered. The IHIS data originally released utilized the since removed NCHS public use files that contain errors; therefore, IHIS has restored its previous version of these variables, which provide mortality follow up data for 1986-2004. IHIS will prioritize processing and harmonizing the corrected mortality-linked files for 1986-2009 for inclusion with its next data release.
- IHIS staff found and corrected a typographical error in the input data for the variable FAMDELAYCONO in 2009.
- The codes and labels for RELMOM were updated to reflect the inclusion of a new response category in 2013. Prior to 2013, biological and adoptive relationships to the mother were categorized separately. However, beginning in 2013 these were condensed into a single category. All codes with values of greater than 10, or anything other than "NIU" or "Biological", are off by one category (i.e., "adoptive" is mistakenly coded as "biological or adoptive", "step" is mistakenly coded as "adoptive", "foster" is mistakenly coded as "step", etc.) in any extracts made after June 28, 2014. The error has been corrected. Values for RELPOP and RELSIB were and remain correctly coded for this change.
- The frequencies for SINGLE were updated to more accurately reflect the universe of all persons in 1989. Cases previously classified as "NIU" have been recoded as missing values.
- The variable SDENTAL was incorrectly coding all persons to "NIU" in 1993-1996. This has been corrected and the variable now reflects the correct codesa nd frequencies for these years. No other years were affected.
- The language in the variable description for HICHANGEYR included misleading language. The description has been updated to reflect that a "yes" response indicates that a person retained the same type of insurance coverage for the past 12 months.
- The value labels for the 2007 complementary and alternative medicine (CAM) variables that report the most important condition a person treated using CAM therapies were updated. The labels and frequencies have not changed; but the numeric output codes have been updated for those therapies also available in 2012 to improve comparability over time. Affected variables are ACUTCONMOST, BIOTCONMOST, COMTCONMOST, DITTCONMOST, EHTTCONMOST, FOKTCONMOST, HER1TCONMOST, HER2TCONMOST, HOMTCONMOST, HYPTCONMOST, MASTCONMOST, MOVTCONMOST, NATTCONMOST, RELTCONMOST, and YTQTCONMOST.
- The following variable names were changed to allow for better harmonization with the 2012 CAM supplement:
Previous Variable Name Updated Variable Name ACUSWELL ACUUSWELL ACUSENERGY ACUUSENERGY ACUSIMMUN ACUUSIMMUN ACUSMEDCOST ACUUSMEDCOST ACUSCOMBO ACUUSCOMBO ACUSMEDFAIL ACUUSMEDFAIL ACUSRELREC ACUUSRELREC ACUSHCREC ACUUSHCREC HER1TNPMED HER1NPMED HER1TPMED HER1PMED HER1TPT HER1PT HER1WELL HER1USWELL HER1HCREC HER1USHCREC HER1IMMUN HER1USIMMUN HER1MEDCOST HER1USMEDCOST HER1MEDFAIL HER1USMEDFAIL HER1RELREC HER1USRELREC HER1TCOUN HER1COUN HER1TCOUNTIM HER1COUNTIM HER1TNPMEDTI HER1NPMEDTI HER1TPMEDTIM HER1PMEDTIM HER1TPTTIM HER1PTTIM HER2TCOUN HER2COUN HER2TNPMED HER2NPMED HER2TPMED HER2PMED HER2TPT HER2PT HER2TSURG HER2SURG HER2HCREC HER2USHCREC HER2IMMUN HER2USIMMUN HER2MEDCOST HER2USMEDCOST HER2MEDFAIL HER2USMEDFAIL HER2RELREC HER2USRELREC HER2WELL HER2USWELL HER2TCOUNTIM HER2COUNTIM HER2TNPMEDTI HER2NPMEDTI HER2TPMEDTIM HER2PMEDTIM HER2TPTTIM HER2PTTIM HER2TSURGTIM HER2SURGTIM
March 2, 2015.
Changes to the data since October 6, 2014, release of newly integrated IHIS 2013 supplements, historic AIDS testing variables, person-level linking keys, release of full documentation for all available variables, modifications and corrections to data.
- The 2013 supplements not included in the October 2014 IHIS data release have been integrated. These include 2013 variables on asthma, cancer screening, health care access and utilization, disability, epilepsy, food security, heart disease and stroke prevention, hepatitis, immunization, immunosuppression, internet access and email usage, mental health, mental health services, and tobacco. IHIS is also releasing a series of historic variables with information about HIV/AIDS testing; these include variables on reasons for being tested, reasons for not being tested, locations of testing, information about testing, and discussion of test results. Additionally, this release provides full documentation for an additional 1,250 variables on topics including exercise, weight control, chronic mental illness, colon cancer testing, insurance, public health service tests, quitting smoking, mammograms, Pap testing, hypertension, income, and HIV/AIDS information and testing. All integrated IHIS variables now have full documentation, including a description of the variable, an overview of the codes, universe information, and a discussion about comparability of the variable over time. Survey text is now available for integrated 2012 and 2013 IHIS variables. Additionally, the original NHIS person-level linking keys (HHX, FMX, and PX) for the 1997-forward samples and day of interview (INTERVWDAY) for the 1970-1996 samples are now available.
To better serve users, IHIS upgraded the system that processes data made available on its website. As part of this process, IHIS did a thorough inventory of existing variables and programming, uncovering typographical errors as well as opportunities for improving comparability. Because of the more thorough review of our variables, there are more revisions than usual. These changes are documented below and arranged by variable topic.
- Health Insurance Variables
- Pre-1997 conditions variables from condition records
- Complementary and Alternative Medicine Variables
- Other Variables
Health Insurance Variables
- Certain summary and key health insurance variables were modified for cases of partially missing information. For variables that summarize information across multiple plans with partially missing information, IHIS now prioritizes the non-missing information when coding these cases. Where persons who reported not having a certain coverage feature for a plan, but also reported being uncertain about their coverage by that plan (or have missing data for coverage by the plan) were previously coded as unknown/missing, these persons are now coded as "no" responses, giving priority to their known "no" response to the specific plan feature over missing information on a less informative variable. For example, the variable HIPMDOPR reports if a person has any private insurance plan that pays any costs for a doctor not on the plan's preferred list. HIPMDOPR has been reconstructed so persons who definitively reported that their private insurance plan would pay for this but have missing data on if they are covered by this plan are now coded as responding "yes" instead of missing. Variables affected by this include HIPBUYOWNR, HIPDENTCOVR, HIPMDLISR, HIPMDOPR, HIPMDPICR, HIPTYPER, HINOUNEMPR, and HIPWORKR in all available samples. Additionally, HIPBUYWONR was updated to address "unknown" cases that were mistakenly being coded to "no".
- Where possible, more nuanced missing codes were made available for variables. Users may notice that where some health insurance variables previously had missing codes of 9 only, there are now codes specifying "unknown-refused" (7), "unknown-not ascertained" (8), or "unknown-don't know" (9).
- Additionally, typographical errors were corrected in the programming for the following variables, resulting in changes to the output codes: HIPDENTCOVR for 2004-2013; SINGLE in 1993-1996;
- The missing codes for the variable HIP4MDPIC in 1992-1996 were updated to create coding consistent with other variables. Only the codes were changed; the underlying frequencies and data remain the same.
- The previous programming for HINOTCOV in 1992 previously eliminated all legitimate observations; correct programming has been restored.
- The previous programming for HINOTCOV in years other than 1992 prioritized incomplete data cases over known cases; the new version of this variable gives precedence to persons who specifically report a known lack of coverage (output code of 2 or "yes, has NO coverage"), persons who have known coverage (output code of 1 or "no, has coverage"), followed by unknown/missing observations. Because this variable asserts that persons have NO coverage, cases with missing data are coded conservatively and continue to receive unknown codes.
- The previous programming for HINOTCOVE in 1997 incorrectly assigned all values to either 2 "Covered" or 8 "Unknown - not ascertained." The programming has been updated to produce the correct assignment of values.
- The variable HIPTYPER was updated to consistently prioritize having any HMO plan; the variable description reflects this change.
- The coding scheme for pre-1997 person-level conditions variables, created from condition-level records, was modified slightly. The previous scheme assigned information from only the first condition record with each condition code (e.g., ICD-9 code), regardless of how the condition record was generated. The modified coding scheme searches through all condition records for each person and prioritizes any information provided in direct response to a conditions survey question. This affects a very small number of cases, changing responses from "no reported conditions" (codes of 1 or 10) or "condition indicated somewhere other than a direct response to a conditions survey question" (codes 22, 212, 222, 232) to "Yes, indicated by a response to a direct conditions survey question."
- The variable FEMTROUBYRC was also modified to prioritize more specific sub-conditions included in this variable. The variable now prioritizes any infertility records in the coding scheme, followed by inflammatory disorder of the female pelvic organs, then other disorders of the female reproductive tract (previous coding scheme first categorized inflammatory disorders, then other disorders, then infertility). This affects only a marginal number of cases where persons reported multiple condition records related to problems with female reproductive organs.
- IHIS staff found an error in the linking keys for the 1983 and 1992 conditions records. In 1983, no persons were previously reporting "yes" responses to any conditions because of this error; the 1983 conditions frequencies have since been corrected and correctly report the conditions experienced by persons. In 1992, repairing these linking keys allowed for the inclusion of additional conditions records. No records were eliminated or changed from "yes" to "no" in this correction; only additional records have been included.
- IHIS staff found and corrected an error in the source data for the variable YTQEXNO. Frequencies have been corrected.
- The variable VITPAIDL, created using special programming, was modified to better specify a single marginal case where, in the original NHIS data, the person reported an unknown value for frequency and amount spent purchasing vitamins, but was classified as "not in universe" in the corresponding frequency time unit NHIS variable.
- The variable MASPAIDT was updated to better specify marginal cases where persons report missing information about insurance coverage for any or all of the part of their massage treatment costs, but provide a legitimate response to the variable asking for the out-of-pocket amount spent. These cases were previously classified as "not in universe", but have been modified to report the total amount the person reported spending out of pocket on massage therapy.
- Sample children were inadvertently excluded from the variables EHTEV, FOKTCANC, DITPRITEV, MOVFELD, and MOVPILAT in 2012. The sample adult frequencies remain the same; sample children are now included.
- IHIS staff found an error in the codes for the variable TPASTEWHITE. The categorical labels for these codes have been updated; previous labels erroneously referred to meeting ADA and FDA standards, but the underlying data only refer to marketing strategies of toothpastes.
- The IHIS variable STRATA previously classified a limited number of "not in universe" observations inconsistently in 1969-1984. These cases have been correctly given values of 0 to indicate their "not in universe" status; these STRATA cases were previously recoded to 1000 in 1969-1972 and 2000 in 1973-1984.
- Because of different rounding conventions in programming languages, a limited number of cases for the variable HHWEIGHT in the 1974-1996 samples and BMICALC in all samples were previously rounded down in instances where the computation of HHWEIGHT ended in exactly .50; while a byproduct of how different programming languages round, it is mathematically incorrect. The new data conversion program correctly rounds these cases up.
- A typographical error in the input data for the variable IMPFAMTCFLAG was corrected in 2009 and 2010.
- A typographical error in the classification of not in universe codes was fixed for the variable DIFSCORE in 2001, 2003, and 2004. Values previously coded as 97 are now correctly displayed under the expected NIU code 96.
- A typographical error in the programming for the variable SMOKEALARM was corrected in 1994; "no" and "yes" responses were inadvertently shifted up one response category, where "no" responses were mistakenly listed as "yes", and "yes" responses were mistakenly listed as "unknown-refused". Frequencies and codes have been corrected; this only affects 1994.
- Nineteen "not in universe" cases for the variable OPOUTPAT2 in 1981 were mistakenly being classified as 96 rather than 0. While 96 sometimes represents a "not in universe" code in other IHIS variables, for OPOUTPAT2 the "not in universe" code is 0 and 96 represents "replacement and removal of therapeutic devices."
- A typographical error in the source data for the variables IRECODE1, IRECODE2, and IRECODE3 were found and fixed in the 2013 sample. These variables are now corrected; these typographical errors affected only the injury-level variables; the person-level injury variables are NOT affected by this change.
- The injury-level variable IRDAYSLB in the 2013 sample was incorrectly specifying all values as 0 because of a typographical error in the special programming; this has been corrected and lower bound values for number of days since the injury/poisoning episode are now being correctly reported.
- A scientific notation character from the original data in the variable IRDAYSUB for the 2013 sample was handled incorrectly in previous special programming. Three cases where output codes previously read 1003 or 2003 have been corrected to 1000 and 2000, respectively.
- An error causing incorrect value labels for two variables that report the year of an event were updated. In the 2010 sample, the variables HYSTDYR (year of hysterectomy) and SKNXMDYR (year of most recent skin cancer exam) incorrectly labeled the repsonse categories "2007", "2008", "2009", and "2010" as "not in universe". The labels for these values now report the correct year.
- The codes for the variable PAPLTOLDYN were incomplete in the 2010 sample. "Only told if there was a problem" (3) was added in; these values had previously been assigned to "Unknown-refused" (7). Missing codes were correspondingly misassigned as well; all missing codes have since been updated to correctly reflect the reason for the missing data (i.e., "refused", "not ascertained", "don't know").
- A number of variables contained incomplete information for the translation of original data codes; a systematic review was conducted and all instances have been corrected. The following variables are affected by the correction:
Variable Samples Affected Number of Cases Previous Code New Code ALCDAYS2WK 1988 39 0 28 BSNUM 1987 8 0 28 CNCERVAG 2010 1 0 99 COKUSWAL 1991 98858 0 6 CSOFFGR 1991 307 No code 99 CXRAYREX 1974 90725 0 50 (3 cases), 96 EHDOTHER 1987 2621 0 9
October 6, 2014.
Changes to the data since July 29, 2014, release of new IHIS 2013 imputed income data, episode-level injury and poisoning variables available for hierarchical extracts, and release of full documentation for over 1,250 additional variables, modifications and corrections to data.
- This release includes access to the new IHIS hierarchical extract system, which allows users to select episode-level data for injuries and poisonings as well as person- and household-level data. For more information on these episode-level data, please see the Injury and Poisoning Supplement User Note.
- IHIS released 2013 imputed income variables. New 2013 variables and variables from reoccurring supplements not available in 2012 will be released sometime in fall 2014.
- IHIS added full documentation for more than 1250 variables currently available on the IHIS website on topics including: child health conditions, digestive conditions treatment, foot problems, housing modifications, insurance, limitation, women's health, and work exposure.
- In response to a user query, IHIS has corrected an error in the response categories for RELMOM. When updating response categories to reflect the concatenation of multiple response categories in 2013, response categories for previous samples were not all updated accordingly. This will affect frequencies for 1998-2012 for the categories of stepmother, foster mother, mother-in-law, unknown-refused, and unknown-not ascertained. This error only affects data extracts made between July 31, 2014 and September 17, 2014. All extracts prior to July 31, 2014 and frequencies for the "biological" and "adoptive" response categories in 1998-2012 are not affected by this correction.
- In response to an inquiry from our colleagues at SHADAC, IHIS corrected reversed response categories for the variable SMOKEV in 2013. Persons who made data extracts prior to September 17, 2014 should switch the yes and no codes for the correct values.
- In response to a user query, IHIS re-adjusted the length of the variable NHISPID for 1997-forward. The previous version eliminated a leading zero, creating a variable that was only 15 columns wide instead of the anticipated 16 columns. Users may revise their extracts using the IPUMS extract system to update the value of NHISPID, or modify their existing extracts on their own by inserting a zero into the string value of NHISPID after the first 6 values (i.e., at the end of "00" followed by the year of the survey). While exploring this issue in NHISPID, IHIS staff found and corrected an error in the source data for NHISHID in the 1968 sample. Only the 1968 sample has been modified; all samples reflect the components specified in the IHIS user note on linking.
- After reviewing the Safety Gear and Behavior variables, IHIS made changes to streamline the variables related to seatbelt use. SBELTCHFREQ2 was combined with SBELTCHFREQ to create a single variable that provides data on use of seat belts among children across available samples. The variable SBELT was modified to create a single variable providing data on the use of seat belts among adults across available samples.
- The following variables available in the 1977 sample were updated to create more consistent coding of not in universe values: AMTBEER, AMTLIQUOR, AMTWINE, DRANKFIVE, HASBEER, HASLIQUOR, HASWINE, PROBAVAIL, PROBCOST, PROBGETCARE, PROBHRS, PROBPREVCARE, PROBTRAN, PROBWHERE, HEIGHT, and WEIGHT. In 1977, these variables were asked for a sub-sample of randomly selected persons ages 20 and older who can be identified by the flag SUBSRESP77. Persons selected to respond to these questions who did not complete the questionnaire are placed into different response categories for each question in the original NHIS data. For more detail on how selected sub-sample persons who did not respond are handled in each variable, please see the variable description. Persons wishing to recategorize these non-responding selected subrespondents should use SUBSRESP77 to identify and reassign these persons. The variables asked of this one-third subsample previously indicated that persons should use the IHIS variable PERWEIGHT; after a thorough review of the limited NHIS documentation on these variables, IHIS has released a different weight for these variables: SUB77WT. The Weight tabs for all relevant variable pages have been updated to reflect this change. Other variables affected by this change are BREAKFAST, SNACKS, PHYSACTIVE, WEIGHTK, HRSLEEP, SMOKESTATUS1, SMOKENOW, CIGSDAY.
- IHIS modified the names of several key Insurance variables to improve clarity.
- IHIS has also combined several health insurance variables to reduce redundancy.
- For additional information on health insurance variables, please see the IHIS user note on using IHIS Insurance variables
- IHIS released 2013 variables that were also included in the 2012 sample and a newly available variable on sexual orientation (SEXORIEN). New 2013 variables and variables from reoccurring supplements not available in 2012 will be released sometime in fall 2014.
- IHIS added full documentation for more than 950 variables currently available on the IHIS website on topics including: 2012 Voice, Speech, Language, and Swallowing supplement, street drugs, medical care, select insurance variables, emotional help, child medication, cancer knowledge, and general health.
- A set of variables introduced in 2011 that capture reasons for most recent ER visit, ERLAMBUL, ERLCLOSEST, ERLDRCLOSED, ERLDRSENT, ERLHOSPHELP, ERLNOTHER, ERLSERIOUS, and ERLUSUALPL, were combined with information contained in alternate versions of these variables covering quarter 2 of 2012 through 2013 (ERLAMBULR, ERLCLOSESTR, ERLDRCLOSEDR, ERLDRSENTR, ERLHOSPHELPR, ERLNOTHERR, ERLSERIOUSR, and ERLUSUALPLR). The alternate versions were removed from the IHIS database.
- To accommodate new response categories for family relationship variables RELMOM, RELPOP, and RELSIB, IHIS updated the value labels for these variables. These changes do not affect frequencies.
- In response to a user query, IHIS staff corrected a typographical error in the data source for the variable SAWMENT in the 2012 sample.
- A typographical error in the data source for the variable HINOFAMR was corrected in the 2012 sample.
- The not in universe category for variable MOMPNUM was corrected. The variable reports the person number of the mother in the household. The previous universe statement read "all persons" and categorized "no mother in the household" as a separate response category. The universe now correctly reads "persons whose mother is present in the household". This affects value labels, but not frequencies for the 1998-2012 samples.
- The IHIS online system incorrectly associated SUPP1WT with variables from the family disability supplement in the 2012 sample, when they should have been associated with SUPP2WT. Variables from the family disability supplement are now correctly associated with SUPP2WT and variables from the functioning and disability supplement are now correctly associated with SUPP1WT.
- NHISHID and NHISPID for the 1963-1967 samples were missing the value of year in the first four columns. The latest release corrects this error, so that the values of NHISHID and NHISPID for pre-1968 samples are consistent with 1968-forward samples.
- The universe and codes for DISTESTFLG were updated for 2011-2012. The previous universe was persons in households that received the family style disability questions, coding persons who received the person-style Adult Disability or Child Disability questions as NIU. Although this was not incorrect, the DISTESTFLG universe has been updated to include all persons and includes flags for both persons in families randomly selected to receive the Family Disability (as well as Adult Functioning and Disability) Questions and persons randomly selected to receive the Adult Disability and Child Disability questions.
- The 1997-1999 NHIS included person-level injury and poisoning records, where injury and poisoning episodes were attached to the person level file. IHIS has created person-level variables comparable to those available in 1997-1999 based on the episode level injury and poisoning data for 2000-2012. These variables are now available through the IHIS data extract system.
- Full documentation is available for over 1,000 additional variables. Topics covered by these fully documented variables include: breast exams, child schooling, cancer knowledge, diabetes, firearms, food knowledge, health information sources, radon, and vaccinations.
- The variables HOMELESSEV1 and HOMELESSEV2 were combined into a single variable HOMELESSEV. Although the survey question is the same across 2000-2010, the universe for 2000-2001 is substantially different from the universe for 2002-2010. Data users should review the Comparability tab for HOMELESSEV for full details.
- The variable BREXLIFE was eliminated. The data available from BREXLIFE can be found in a more accessible format in BREXSELFTP, which reports the time period associated with the frequency that the respondent performs self-breast exams, and BREXSELFNO, which reports the number of times the respondent performs self-breast exams per time period.
- The variable HAVEROUTPL was eliminated. The data available from HAVEROUTPL can be found in the harmonized variable USUALPL, which reports if the person has a usual or routine place for medical care.
- The following variables were eliminated from the Cancer Family History variables group: BFCXCAN, FBCXCAN, BSCXCAN, BSOVCAN, FBOVCAN, BFOVCAN, BSUTCAN, FBUTCAN, BFUTCAN, BMPSCAN, BDPSCAN, FSPSCAN, BMTTCAN, BDTTCAN, and FSTTCAN. These variables were included as part of the exhaustive list of cancer variables that report if family members had certain types of cancer; however, the eliminated variables represented unrealistic combinations of sex and cancer type. For example BFCXCAN reported if the person's biological father had uterus cancer. Variables deleted were related to cervix, ovary, prostate, testis, and uterus cancer. No variables related to breast cancer were eliminated. There were no recorded "yes" or "mentioned" observations for any of these eliminated variables.
- IHIS has revised the extensive list of food frequency variables to improve comparability across years; to avoid confusion between the newly integrated variables and those that were only available for one or two samples, many variables have been eliminated. Please use the table below to determine which variables have been eliminated and what replacement variable contains the same information in a more comparable format.
- A typographical error in the data source for the variable VITBUY was corrected; this will affect VITBUY frequencies for 2012.
- In response to a user query, IHIS staff corrected a recoding error and changed the response categories for DIFTNONEED.
April 28, 2015.
Changes to the data since March 2, 2015, release of historic imputed income data for 1990-1996, over 2000 harmonized complementary and alternative medicine variables for 2012, historic child health supplement variables, and corrections to data.
Pre-1997 conditions variables from condition records
Complementary and Alternative Medicine (CAM) variables
Removed and modified variables.
|New Variable||Variable Description||Deleted Variable|
|Variables edited by NCHS based on insurance plan name (1997 forward)|
|HIPRIVATEE||Has any private health insurance||HIPRIVATER|
|HIMCAIDE||Has Medicaid health insurance||MCAIDR|
|HIMCAREE||Has Medicare health insurance||MCARER|
|HISTATEE||Has state-sponsored health insurance||HISTATER|
|HIOTHGOVE||Has some other government-program||HIOTHGOVR|
|HIPUBCOVE||Has any public coverage||New variable|
|HIMILITE||Has Military coverage (TRICARE (CHAMPUS), CHAMP-VA, and VA coverage)||HIMILITR|
|HINOTCOVE||Has no health insurance||UNINSURED|
|SINGLEE||Has a single service health care plan||SINGLER|
|SDENTALE||Has a single service plan for dental care||SSDENTAL|
|HIHSE||Has Indian Health Service||HIHSR|
|IHIS-created variables for bridging pre-1997 and 1997-forward samples (based on non-edited variables)|
|HINDIAN||Has Indian Health Service||HINDIANR|
|HIPRIVATE||Has any private health insurance||HIPRIVATEANYR|
|HIPUBCOV||Has any public covreage (Medicaid, Medicare, state-sponsored insurance, or CHIP)||HIPUBLICR|
|HINOTCOV||Has no health insurance||HASNOCOVR|
|SINGLE||Has single service health care plan||HISINGLER|
|SDENTAL||Has single service plan for dental care||SSDENTALR|
|Retained Variable||Variable Description||Eliminated Variable|
|HI1HMOCOVR||First plan mentioned was a health maintenance organization||HI1HMOCOV|
|HI2HMOCOVR||Second plan mentioned was a health maintenance organization||HI2HMOCOV|
|HI3HMOCOVR||Third plan mentioned was a health maintenance organization||HI3HMOCOV|
|HI4HMOCOVR||Fourth plan mentioned was a health maintenance organization||HI4HMOCOV|
|HI1WHO||Policy holder of the first health insurance plan||HI1WHOR|
|HI2WHO||Policy holder of the second health insurance plan||HI2WHOR|
|HI3WHO||Policy holder of the third health insurance plan||HI3WHOR|
|HI4WHO||Policy holder of the fourth health insurance plan||HI4WHOR|
|HI5WHO||Policy holder of the fifth health insurance plan||HI5WHOR|
|HOSPTYPE||Type of plan which pays any part of a hospital bill||HOSPTYPE2|
|HI6WORK||Indicates if sixth insurance plan was originally obtained through work||HI6OBEMP|
|HI5EMP||Indicates if fifth insurance plan is carried through an employer or union||HI5EMHIPAY|
July 29, 2014.
Changes to the data since June 30, 2014, release of new IHIS 2013 data, release of full documentation for 950 additional variables, modifications and corrections to data.
Removed and modified existing variables.
June 30, 2014.
Person-level injury variables are now available for 2000-present, variable-level documentation has been expanded to an additional 1,000 variables, several variables were replaced by streamlined versions, and the food frequency variables were updated to enhance comparability over time.
|Deleted Variable||Deleted Variable Description||New Variable|
|BEANSMNO||Frequency eating beans: number of time units, month recall||BEANNO|
|BEANSMTP||Frequency eating beans: time period, month recall||BEANTP|
|BEANSMYR||Recode: frequency eating beans, times per year, month recall||BEANYR|
|BEANSNO||Frequency eating beans: number of time units, year recall||BEANNO|
|BEANSTP||Frequency eating beans: time period, year recall||BEANTP|
|BEANSYR||Recode: frequency eating beans, times per year, year recall||BEANYR|
|BREADMNO||Frequency eating whole grain bread: number of time units, month recall||BREADNO|
|BREADMTP||Frequency eating whole grain bread: time period, month recall||BREADTP|
|BREADMYR||Recode: frequency eating whole grain bread, times per year, year recall||BREADYR|
|DARBREDNO||Frequency eating dark breads: number of time units, year recall||BREADNO|
|DARBREDTP||Frequency eating dark breads: time period, year recall||BREADTP|
|DARBREDYR||Recode: frequency eating dark breads, times per year, year recall||BREADYR|
|CANDYMNO||Frequency eating chocolate or other candy: number of time units, month recall||CANDNO|
|CANDYMTP||Frequency eating chocolate or other candy: time period, month recall||CANDTP|
|CANDYNO||Frequency eating chocolate candy: number of time units, year recall||CANDNO|
|CANDYTP||Frequency eating chocolate candy: time period, month recall||CANDTP|
|CERBRAN||Ate all bran cereals when eating cereal, month recall||CEREALTYPE|
|CERCOOK||Ate cooked cereals when eating cereal, month recall||CEREALTYPE|
|CERFIBER||Ate cereals with some bran or fiber when eating cereal, month recall||CEREALTYPE|
|CERNOFIBER||Ate cereals with little bran or fiber when eating cereal, month recall||CEREALTYPE|
|CEROTHER||Ate other cereals when eating cereal, month recall||CEREALTYPE|
|CEREFORYR||Recode: frequency eating highly fortified cereal, times per year, year recall||CEREALYR CEREALTYPE|
|CERFORNO||Frequency eating highly fortified cereal: number of time units, year recall||CEREALYR CEREALTYPE|
|CERFORTP||Frequency eating highly fortified cereal: time period, year recall||CEREALYR CEREALTYPE|
|COLDCMNO||Frequency eating cold cereal: number of time units, month recall||CEREALYR CEREALTYPE|
|COLDCMTP||Frequency eating cold cereal: time period, month recall||CEREALYR CEREALTYPE|
|COLDCMWK||Recode: frequency eating cold cereal, times per week, month recall||CEREALYR CEREALTYPE|
|COLDCMYR||Recode: frequency eating cold cereal, times per year, month recall||CEREALYR CEREALTYPE|
|COLDCNO||Frequency eating cold cereal: number of time units, year recall||CEREALYR CEREALTYPE|
|COLDCNUM||Frequency eating cold cereal: number of time units, servings per day or week||CEREALYR CEREALTYPE|
|COLDCTIM||Frequency eating cold cereal: time period, servings per day or week||CEREALYR CEREALTYPE|
|COLDCTP||Frequency eating cold cereal: time period, year recall||CEREALYR CEREALTYPE|
|COLDCWEEK||Recode: frequency eating cold cereal, times per week, servings per day or week||CEREALYR CEREALTYPE|
|COLDCYR||Recode: frequency eating cold cereal, times per year||CEREALYR CEREALTYPE|
|GRANONO||Frequency eating high fiber cereals: number of time units, year recall||CEREALYR CEREALTYPE|
|GRANOTP||Frequency eating high fiber cereals: time period, year recall||CEREALYR CEREALTYPE|
|GRANOYR||Recode: frequency eating high fiber cereals, times per year, year recall||CEREALYR CEREALTYPE|
|OATMNO||Frequency eating cooked cereals: number of time units, year recall||CEREALYR CEREALTYPE|
|OATMTP||Frequency eating cooked cereals: time period, year recall||CEREALYR CEREALTYPE|
|OATMYR||Recode: frequency eating cooked cereals, times per year, year recall||CEREALYR CEREALTYPE|
|CHEESMNO||Frequency eating cheese: number of time units, month recall||CHEESENO|
|CHEESMTP||Frequency eating cheese: time period, month recall||CHEESETP|
|CHEESNO||Frequency eating cheese: number of time units, year recall||CHEESENO|
|CHEESTP||Frequency eating cheese: time period, year recall||CHEESETP|
|CHIPSMNO||Frequency eating chips: number of time units, month recall||CHIPNO|
|CHIPSMTP||Frequency eating chips: time period, month recall||CHIPTP|
|CHIPSMYR||Recode: frequency eating chips, times per year, month recall||CHIPYR|
|CHIPSNO||Frequency eating chips: number of time units, year recall||CHIPNO|
|CHIPSTP||Frequency eating chips: time period, year recall||CHIPTP|
|CHIPSYR||Recode: frequency eating chips, times per year, year recall||CHIPYR|
|COOKIESMNO||Frequency eating cookies, cake, pie, or brownies: number of time units, month recall||SWEETSYR DONUTYR|
|COOKIESMTP||Frequency eating cookies, cake, pie, or brownies: time period, month recall||SWEETSYR DONUTYR|
|DONUTMNO||Frequency eating doughnuts, sweet rolls, or muffins: number of time units, month recall||SWEETSYR DONUTYR|
|DONUTMTP||Frequency eating doughnuts, sweet rolls, or muffins: time period, month recall||SWEETSYR DONUTYR|
|FRIESMNO||Frequency eating fried potatoes: number of time units, month recall||FRIESPNO|
|FRIESPNO||Frequency eating fried potatoes: time period, month recall||FRIESPTP|
|FRIESMYR||Recode: frequency eating fried potatoes, times per year, month recall||FRIESPYR|
|FRIESNO||Frequency eating fried potatoes: number of time units, year recall||FRIESPNO|
|FRIESTP||Frequency eating fried potatoes: time period, year recall||FRIESPTP|
|FRIESYR||Recode: frequency eating fried potatoes, times per year, year recall||FRIESPYR|
|FRUITMNO||Frequency eating fruit: number of time units, month recall||FRUTNO|
|FRUITMTP||Frequency eating fruit: time period, month recall||FRUTTP|
|FRUITMWK||Recode: frequency eating fruit, times per week, month recall||FRUTWK|
|FRUITNO||Frequency eating fruit: number of time units, servings per day or week||FRUTNO|
|FRUITWK||Recode: frequency eating fruit, times per week, servings per day or week||FRUTWK|
|SERVFRUTP||Frequency eating fruit: time period, servings per day or week||FRUTTP|
|SERVFRUWKR||Recode: frequency eating fruit, times per week, servings per day or week||FRUTWK|
|HOTDGMNO||Frequency eating hot dogs: number of time units, month recall||HOTDOGNO|
|HOTDGMTP||Frequency eating hot dogs: time period, month recall||HOTDOGTP|
|HOTDGMYR||Recode: frequency eating hot dogs, times per year, month recall||HOTDOGYR|
|HOTDGNO||Frequency eating hot dogs: number of time units, year recall||HOTDOGNO|
|HOTDGTP||Frequency eating hot dogs: time period, year recall||HOTDOGTP|
|HOTDGYR||Recode: frequency eating hot dogs, times per year, year recall||HOTDOGYR|
|ICECREMMNO||Frequency eating ice cream: number of time units, month recall||ICECREAMNO|
|ICECREMMTP||Frequency eating ice cream: time period, month recall||ICECREAMTP|
|ICECREMTP||Frequency eating ice cream: time period, year recall||ICECREAMTP|
|MAYOMNO||Frequency eating mayonnaise/dressing: number of time units, month recall||MAYODRNO|
|MAYOMTP||Frequency eating mayonnaise/dressing: time period, month recall||MAYODRTP|
|MAYOMYR||Recode: frequency eating mayonnaise/dressing, times per year, month recall||MAYODRYR|
|MAYONO||Frequency eating mayonnaise/dressing: number of time units, year recall||MAYODRNO|
|MAYOTP||Frequency eating mayonnaise/dressing: time period, year recall||MAYODRTP|
|MAYOYR||Recode: frequency eating mayonnaise/dressing, times per year, year recall||MAYODRYR|
|MILK2PNO||Frequency drinking 2% milk: number of time units, year recall||MILKYR MILKTYPE|
|MILK2PTP||Frequency drinking 2% milk: time period, year recall||MILKYR MILKTYPE|
|MILK2PYR||Recode: frequency drinking 2% milk, times per year, year recall||MILKYR MILKTYPE|
|MILKMTYPE||Type of milk usually consumed||MILKTYPE|
|MILKMWK||Recode: frequency drinking milk, times per week, month recall||MILKYR|
|MILKMYR||Recode: frequency drinking milk, times per year, month recall||MILKYR|
|MILKSKINO||Frequency drinking skim milk: number of time units, year recall||MILKYR MILKTYPE|
|MILKSKITP||Frequency drinking skim milk: time period, year recall||MILKYR MILKTYPE|
|MILKSKIYR||Recode: frequency drinking skim milk, times per year, year recall||MILKYR MILKTYPE|
|MILKUSE||Kind of milk usually used||MILKTYPE|
|MILKWNO||Frequency drinking whole milk: number of time units, year recall||MILKYR MILKTYPE|
|MILKWTP||Frequency drinking whole milk: time period, year recall||MILKYR MILKTYPE|
|MILKWYR||Recode: frequency drinking whole milk, times per year, year recall||MILKYR MILKTYPE|
|PASTAMNO||Frequency eating pasta: number of time units, month recall||PASTASNO|
|PASTAMTP||Frequency eating pasta: time period, month recall||PASTASTP|
|PASTAMYR||Recode: frequency eating pasta, times per year, month recall||PASTASYR|
|PASTANO||Frequency eating pasta: number of time units, year recall||PASTASNO|
|PASTATP||Frequency eating pasta: time period, year recall||PASTASTP|
|PASTAYR||Recode: frequency eating pasta, times per year, year recall||PASTASYR|
|PASTRYNO||Frequency eating doughnuts, cookies, cake, or pastry: number of time units, year recall||SWEETSYR PIEYR|
|PASTRYTP||Frequency eating doughnuts, cookies, cake, or pastry: time period, year recall||SWEETSYR PIEYR|
|PASTRYYR||Recode: frequency eating doughnuts, cookies, cake, or pastry, times per year||SWEETSYR PIEYR|
|PIENO||Frequency eating pie: number of time units, year recall||SWEETSYR PIEYR|
|PIETP||Frequency eating pie: time period, year recall||SWEETSYR PIEYR|
|PIZMNO||Frequency eating pizza: number of time units, month recall||PIZZANO|
|PIZMTP||Frequency eating pizza: time period, month recall||PIZZATP|
|PIZNO||Frequency eating pizza: number of time units, year recall||PIZZANO|
|PIZTP||Frequency eating pizza: time period, year recall||PIZZATP|
|POTATOMNO||Frequency eating non-fried potatoes: number of time units, month recall||POTATONO|
|POTATOMTP||Frequency eating non-fried potatoes: time period, month recall||POTATOTP|
|POTATOMYR||Recode: frequency eating non-fried potatoes, times per year, month recall||POTATOYR|
|POTATNO||Frequency eating non-fried potatoes: number of time units, year recall||POTATONO|
|POTATTP||Frequency eating non-fried potatoes: time period, year recall||POTATOTP|
|POTATYR||Recode: frequency eating non-fried potatoes, times per year, year recall||POTATOYR|
|SALADMNO||Frequency eating green salad: number of time units, month recall||SALADSNO|
|SALADMTP||Frequency eating green salad, time period, month recall||SALADSTP|
|SALADMYR||Recode: frequency eating green salad, times per year, month recall||SALADSYR|
|SALADNO||Frequency eating green salad: number of time units, year recall||SALADSNO|
|SALADTP||Frequency eating green salad, time period, year recall||SALADSTP|
|SALADYR||Recode: frequency eating green salad, times per year, year recall||SALADSYR|
|SODAMNO||Frequency drinking soft drinks: number of time units, month recall||SODAPNO|
|SODAMTP||Frequency drinking soft drinks: time period, month recall||SODAPTP|
|SODANO||Frequency drinking soft drinks: number of time units, year recall||SODAPNO|
|SODATP||Frequency drinking soft drinks: time period, year recall||SODAPTP|
|SERVEGNO||Frequency eating vegetables: number of time units, servings per day or week||VEGENO|
|SERVEGTP||Frequency eating vegetables: time period, servings per day or week||VEGETP|
|SERVEGWKR||Recode: frequency eating vegetables, times per week, servings per day or week||VEGEWK|
|VEGMNO||Frequency eating vegetables: number of time units, month recall||VEGENO|
|VEGMTP||Frequency eating vegetables: time period, month recall||VEGETP|
|VEGMWK||Recode: frequency eating vegetables, times per week, month recall||VEGEWK|
|VEGWK||Recode: frequency eating vegetables, times per week, servings per day or week||VEGEWK|
|VEGYNO||Frequency eating other vegetables: number of time units, year recall||OTHVEGNO|
|VEGYTP||Frequency eating other vegetables: time period, year recall||OTHVEGTP|