For all medication-round fills, except diabetic equipment and supplies (see RXNAME), MULTC1 is one of a set of variables that classifies drugs using the Multum Lexicon database therapeutic classification system (for more information, see the following section).
MULTC1 is on the prescribed medication-round fill record (or "medication-round fill record," see RECTYPE for more details on the different record types in IPUMS MEPS). Variables offered on the medication-round fill record through IPUMS MEPS are derived from the prescribed medicines file provided by AHRQ. Please see our overview of the event, medical conditions, and prescribed medicines variables, including how those variables are offered through IPUMS MEPS, and general considerations to keep in mind when conducting analyses using these variables.
IPUMS MEPS reports the universe for each variable based on a thorough review of the original MEPS documentation. Investigating the data may reveal cases that do not meet the stated universe. Users are encouraged to validate universes for their analyses. Additionally, users should proceed with caution when using the Multum Lexicon therapeutic class variables because the classification scheme has changed over time with the addition of new classes and sub-classes and changes to the hierarchy of classes. See the comparability tab for more details.
Multum Lexicon Variables
Cerner Multum, Inc. develops the Multum Lexicon database that MEPS uses to classify drugs reported by respondents in the MEPS-HC into the therapeutic class, sub-class, and sub-sub-class variables. In this classification system, each drug is assigned to a maximum of three therapeutic classes, such as cardiovascular agents or psychotherapeutic agents. Within each therapeutic class, drugs can also be assigned to one or more sub-classes, such as diuretics or antidepressants. Within each sub-class, drugs can also be assigned to one or more sub-sub-classes, such as loop diuretics or SSRI antidepressants. IPUMS MEPS currently offers the first therapeutic class a drug was assigned to as well as the corresponding sub-classes and sub-sub-classes. These variables include:
Multum Lexicon therapeutic class variables
- MULTC1: Multum Lexicon therapeutic class 1
- MULTC1S1: Multum Lexicon therapeutic class 1, sub-class 1
- MULTC1S1S1: Multum Lexicon therapeutic class 1, sub-class 1, sub-sub-class 1
- MULTC1S1S2: Multum Lexicon therapeutic class 1, sub-class 1, sub-sub-class 2
- MULTC1S2: Multum Lexicon therapeutic class 1, sub-class 2
- MULTC1S2S1: Multum Lexicon therapeutic class 1, sub-class 2, sub-sub-class 1
- MULTC1S3: Multum Lexicon therapeutic class 1, sub-class 3
- MULTC1S3S1: Multum Lexicon therapeutic class 1, sub-class 3, sub-sub-class 1
IPUMS MEPS plans to release additional Multum Lexicon therapeutic class variables in the future.
Other Multum Lexicon variables available through IPUMS MEPSTake note: IPUMS MEPS offers corrected Multum Lexicon data
Users should note that in 2017, AHRQ released Multum Lexicon Addendum files for 1996-2013 after discovering incorrect linkages between the MEPS Prescribed Medicines files and the Cerner Multum file, resulting in some incorrect therapeutic classes being assigned. The errors involved some diagnostic tests and medical devices that were accidentally assigned to a therapeutic class and should not have been. These errors included the following:
- Some diabetic supplies erroneously assigned to a sex hormone sub-class in 1996-2002 and then erroneously assigned to a toxoids sub-class in 2003-2010.
- The national drug code (NDC) 00169750111 was being misassigned. It should have been assigned to MULTC1=358 and MULTC1S1=99.
The released addendum files contained corrected versions of the therapeutic class and sub-class variables and PREGCAT. They also contained RXDRGNAM, which was not previously released for 1996-2012. The 2013 Multum Lexicon Addendum file also contained corrected values of RXDRGNAM for some records.
IPUMS MEPS provides the corrected versions of the Multum Lexicon therapeutic class and sub-class variables as well as PREGCAT and RXDRGNAM for all years.
Users using the Multum Lexicon variables should cite Multum Lexicon, AHRQ, and IPUMS MEPS as the data sources.
MULTC1 is a 3-digit numeric variable.
In all samples, diabetic equipment or supplies are assigned a MULTC1 value of 8: "Unknown – Not Ascertained."
The Multum Lexicon therapeutic classification scheme has changed over time, and the Multum Lexicon variables reflect the most recent classification in the year that the data were originally released. For that reason, users should proceed with caution when using the Multum Lexicon variables to conduct trend analyses or to pool years or panels together. Changes to the Multum Lexicon therapeutic classification scheme include the addition of classes and sub-classes and changes in the hierarchy of classes. For example, in 1996-2004, antidiabetic drugs were a sub-class of the hormone class, but starting in 2005, antidiabetic drugs were a sub-class of the metabolic drugs class.
See Multum Lexicon Addendum Files to MEPS Prescription Medicine Files for additional examples of changes to the Multum classification scheme and for more general information about the Multum Lexicon variables.
For a consistent drug classification over time, see RXDRGNAM.
- 1996-2021: All medication-round fills, except diabetic equipment and supplies (see RXNAME).
- 1996-2021 : PERWEIGHT