Jan 2014: More new data released for 2012
Sept 2013: User note on IHIS variables available to monitor progress towards several Healthy People 2020 objectives
Sept 2013: New data released for 2012, imputed income, other topics
Feb 2012: Remaining 2011 data released, Monitoring the ACA, Pre-1997 conditions variables released, Imputed income variables released
Aug 2012: New data released for 2011, imputed income, other topics
Mar 2012: New Insurance Variables Available
Oct 2011: SAMPWEIGHT problem fixed
Oct 2011: New data released for 1963 to 2010
Jan 2011: Online tabulator now available
Nov 2010: New data released on herbs, vitamins, other topics
Aug 2010: New data released for 1969-2009
Aug 2010: BMICALC and linking keys corrected
Jan 2009: Linking key data problems
Dec 2008: Linking syntax file updates
Nov 2008: New Variables Coming Soon
Oct 2008: IHIS Updates Website
The latest IHIS data release added approximately 600 variables, including new variables for the 2012 supplements. New or expanded supplements in 2012 that are now part of IHIS include: child balance; complementary and alternative medicine; enhanced questions on health care access and utilization; food security, child mental health and mental health services; tobacco; voice, speech, and language; heart disease and stroke prevention; as well as internet and email usage. IHIS has also provided new or updated variable-level information pages for an additional 500 existing variables.
The latest IHIS data release has added variables from the 2012 NHIS sample, including the imputed income variables. The 2012 survey continues to include variables used to monitor the Affordable Care Act (see brief at user note for more information on these variables).
In 2012, the NHIS included a Complementary and Alternative Medicine (CAM) Supplement for sample adults and sample children. This collected information for all sample children age 4 and over and sample adults age 18 and over on their use of and payment for 18 kinds of CAM. Information includes recency of use (in the past 12 months), frequency of use, and insurance coverage and out-of-pocket and additional expenses related to CAM. While these questions are similar to the CAM Supplements that were fielded in 2002 (sample adults only) and 2007, not all content is comparable to earlier versions. The 2012 survey also included new questions on CAM in quarters two through four. This data release provides a subset of the 2012 CAM variables and the remainder will be made available in a future data release.
This data release also contains the Child and Adult Disability questions, first included for half the sample persons in the 2010 Quality of Life Supplement and continued in the 2011 Adult Functioning and Disability Supplement. In 2012, several new questions were added to the disability file Functioning and Disability (AFD) section that are similar to the 2010 and 2011 variables, but have minor changes in the universe. These new variables, reflecting the different contexts or universes relative to 2011 and 2010, are forthcoming.
In addition, other new variables from the 2012 NHIS are forthcoming. These include questions from the Adult and Child Voice, Speech and Language Supplements, the Child Balance Supplement, the Adult Internet and Email Usage Section, six new supplemental questions on the use of tobacco products other than cigarettes, and two new supplemental questions about flu shots before, during, or after pregnancy.
IHIS also has provided new or updated variable-level information pages for existing variables collected in various years between 1970 and 2012.
Feb 2012: Remaining 2011 data released, Monitoring the ACA, Pre-1997 conditions variables released, Imputed income variables released
The latest IHIS data release has added the remaining 2011 data that was not released by IHIS in August 2012. New topics covered in 2011 include service in the armed forces; reasons for not having a usual source of care; steps taken in the past year to save money on medical care; most recent ER visit; last health care visit; long-term care insurance; health insurance coverage in the past 3 years; and treatment of children's mental health.
Beginning with the 2011 NHIS, around 85 new questions were added to the NHIS that were designed to monitor the implementation of the Affordable Care Act (ACA). IHIS has created a user note on these variables, and SHADAC has released a brief on the variables.
IHIS now makes it much easier to work with the pre-1997 "condition records." Before 1997, information about health conditions was collected in the form on many-to-one condition records. This data structure made it difficult to analyze the condition records in concert with othere IHIS/NHIS data that treat the person or household as the unit of analysis. IHIS staff have solved this problem by converting the pre-1997 condition records into person-level data. Users can now analyze chronic conditions such as asthma, diabetes, hypertension, and breast cancer over a longer time series than was previously available. For more information, consult the IHIS user note.
The IHIS staff has created new variables that reflect the ratio of imputed income to the federal poverty guidelines. (Note: The federal poverty guidelines are different from the federal poverty thresholds. See here for information on the difference.) These variables (POVIMPHHS1 through POVIMPHHS5) cover 2009-2011 and are constructed from imputed point estimates of income. Users should refer to the variable descriptions for these variables for links to NHIS documentation on appropriate use of variables with imputed data.
The latest IHIS data release has added data from 2011. New variable groups include health care access and utilization, food security, functioning and disability, and fitness center use.
IHIS now includes new summary insurance variables, indicating the type of coverage, the features of private plans, and the reasons for not having coverage, that are consistently coded for the 1980s to the present. Two new user notes, on changes in insurance data collection and the shifting definition of private insurance, are also now available, along with hundreds of other variables addressing various aspects of insurance coverage.
The variable SAMPWEIGHT is once again supplying the correct values.
The lastest IHIS data release has added data from 2010, includes material from the historical public use files from 1963 to 1968, and brings the number of integrated variables available through IHIS to approximately 12,000.
Users can now analyze IHIS data online, using high-speed tabulation software developed at UC-Berkeley. The online tabulator is especially useful for creating frequency and cross-tabulation tables, calculating means, and significance testing. Experienced data users may wish to use the tabulator to get quick or preliminary results before downloading a dataset. Users who do not have experience using a statistical package can now answer simple research questions by creating tables online. In introductory classes on statistics or public health, students can use the tabulator to formulate and test hypotheses about public health trends and differentials, getting results within seconds. A detailed user note provides explanations and examples of how to analyze IHIS data on-line.
The latest IHIS data release increased the number of variables to over 7000. New variable groups include adult and child use of vitamins and herbs, falls and balance problems, hearing and vision problems, and use of aids to mobility. Also newly available is a weight (MORTWTSA) suitable for use with variables from the sample adult files in conjunction with variables on survey participants' mortality and cause of death.
The latest IHIS data release added data from 2007, 2008, and 2009 and increased the number of variables to over 5000. New variable groups include adult and child mental health, cancer family history, use of complementary and alternative medicine, health knowledge, adult leisure-time physical activity, imputed income and earnings, HPV immunization, and mortality and cause of death of survey participants.
The BMICALC (IHIS-calculated Body Mass Index), which was created by programming, initially included some incorrect values for 1982-1995 due to an error in the programming statements. Respondents with unknown values for height were included in the BMI calculation, which yielded artificially low values. The version of BMICALC available as of August 16, 2010 no longer includes those incorrect values. Researchers who used the BMICALC variable for 1982-1995 prior to August 16, 2010 should redo their analyses using the corrected version of the variable.
The original versions of the linking key variables NHISPID (for person-level variables) and NHISHID (for household-level variables) were incorrect. A coding fix for NHISPID was posted in IHIS news on January 27, 2009. The versions of NHISPID and NHISHID available as of August 16, 2010 are correct, and the coding fix is no longer needed.
REVISED: Feb 20, 2009. The linking key variables NHISPID (for person level variables) and NHISHID (for household level variables) in the IHIS extract system are currently incorrect. We have identified and corrected the problem. However, the corrected NHISPID and NHISHID variables will not be available until the next IHIS data update.
In the interim, a simple coding fix for NHISPID can be implemented by users in their own IHIS data. For Stata users, adapt the following code for the years in your IHIS extract:
gen str16 test = "002006" + substr(nhispid,7,10) if year == 2006
replace test = "002005" + substr(nhispid,7,10) if year == 2005
replace test = "002004" + substr(nhispid,7,10) if year == 2004
replace test = "002003" + substr(nhispid,7,10) if year == 2003
replace test = "002002" + substr(nhispid,7,10) if year == 2002
replace test = "002001" + substr(nhispid,7,10) if year == 2001
replace test = "002000" + substr(nhispid,7,10) if year == 2000
replace test = "001999" + substr(nhispid,7,10) if year == 1999
replace test = "001998" + substr(nhispid,7,10) if year == 1998
replace test = "001997" + substr(nhispid,7,10) if year == 1997
replace test = "1996" + substr(nhispid,5,12) if year == 1996
replace test = "1995" + substr(nhispid,5,12) if year == 1995
replace test = "1994" + substr(nhispid,5,12) if year == 1994
replace test = "1993" + substr(nhispid,5,12) if year == 1993
replace test = "1992" + substr(nhispid,5,12) if year == 1992 & hispoversamp !=1
replace test = "1991" + substr(nhispid,5,12) if year == 1992 & hispoversamp ==1
replace test = "1991" + substr(nhispid,5,12) if year == 1991
replace test = "1990" + substr(nhispid,5,12) if year == 1990
replace test = "1989" + substr(nhispid,5,12) if year == 1989
replace test = "1988" + substr(nhispid,5,12) if year == 1988
replace test = "1987" + substr(nhispid,5,12) if year == 1987
replace test = "1986" + substr(nhispid,5,12) if year == 1986
replace test = "1985" + substr(nhispid,5,12) if year == 1985
replace test = "1984" + substr(nhispid,5,12) if year == 1984
replace test = "1983" + substr(nhispid,5,12) if year == 1983
replace test = "1982" + substr(nhispid,5,12) if year == 1982
rename nhispid pidbad
rename test nhispid
For SAS users, adapt the following code for the years in your IHIS extract:
format test $16.;
if year=2006 then test="002006"||substr(nhispid,7,10);
if year=2005 then test="002005"||substr(nhispid,7,10);
if year=2004 then test="002004"||substr(nhispid,7,10);
if year=2003 then test="002003"||substr(nhispid,7,10);
if year=2002 then test="002002"||substr(nhispid,7,10);
if year=2001 then test="002001"||substr(nhispid,7,10);
if year=2000 then test="002000"||substr(nhispid,7,10);
if year=1999 then test="001999"||substr(nhispid,7,10);
if year=1998 then test="001998"||substr(nhispid,7,10);
if year=1997 then test="001997"||substr(nhispid,7,10);
if year=1996 then test="1996"||substr(nhispid,5,12);
if year=1995 then test="1995"||substr(nhispid,5,12);
if year=1994 then test="1994"||substr(nhispid,5,12);
if year=1993 then test="1993"||substr(nhispid,5,12);
For additional information about merging variables from the original NHIS public use data files to IHIS data, please see the user note on merging.
Stata and SAS syntax files for merging variables from the original NHIS public use data files to IHIS data are being revised. Syntax files for 1969 to 1981 are currently unavailable.
In the next couple of weeks, new variables will begin to be added to the IHIS system. This will include new variables from the NHIS 2007 data released this summer, mortality variables from the NHIS-Linked Mortality Files, cancer screening, and cancer family history variables. We will also extend many of the current IHIS variables back in time.
On October 15 2008, IHIS introduced a new look to its website. This upgrade also included a significant redesign of the variable browsing and data extraction system. IHIS users now have more control over how they view the variables available, and they can now select variables from any point in the documentation system. The data extraction system also gives users more flexibility in how they select the years of data and variables they want to download.
Further information about the new browsing and data extraction options, in addition to general aspects of the data series, are available on the FAQ page.