Central Distributor SASD: Description of Data Elements

MDNUM1_S - Physician 1 number (synthetic)

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HCUP encrypted physician identifiers are referred to by different names in the HCUP data across years.

Year	Variable
1988-2000	MDID_S
2001-2002	MDNUM1_S
Beginning with 2003	MDNUM1_R

MDNUM1_S contains a fixed-key (one-to-one) encryption of the supplied physician 1 number (MDNUM1), according to the following rules:

All alphanumeric digits are used in the encryption.
All symbols such as ".,:;'*@" are retained in the encrypted value, but not in the same location.
Leading zeros are encrypted so that the two original physician identifiers "000A6" and "A6" are distinctly different.
When the original physician 1 number and physician 2 number identifiers are the same, the synthetic identifiers, MDNUM1_S and MDNUM2_S, are the same.
When the MDNUM1 in the ambulatory surgery data and the inpatient data are the same, the synthetic identifier, MDNUM1_S is the same.

Except in those data sources where physician license numbers are supplied, it is not known whether the physician identifier MDNUM1_S refers to individual physicians or to groups. If the physician 1 numbers supplied by the data source are not restricted to license numbers, the state-specific note includes available information about reporting practices, including whether MDNUM1_S refers to individual physicians or to groups.

Beginning in the 1993 data, supplied physician 1 identifiers were checked for null characters. If null characters were found, they were replaced by blanks before the identifier was encrypted. Since this conversion was not done in prior years of HCUP data, the encrypted physician 1 identifiers from 1993 on may not match those in earlier years. However, null characters are rarely included.

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Uniform Values

Variable	Description	Value	Value Description
MDNUM1_S	Physician 1 number (synthetic)	16(a)	Synthetic physician identifier
MDNUM1_S	Physician 1 number (synthetic)	Blank	Missing

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State Specific Notes

Colorado

In Colorado two types of physician identifiers are available:

Attending physician is provided in MDNUM1_S and
Physician that performed the principal procedure is provided in MDNUM2_S.

Physician identification numbers may not accurately track physicians across hospitals. The state encourages hospitals to use the Professional State License Number as an identifier, but some hospitals continue to use their own internal identification number. Also, some hospitals appear to pad the Professional State License Number (a 5-digit code). Information was not available from the data source about the prevalence of these practices.

Some hospitals may use one license number for all physicians in order to protect physician confidentiality. Information was not available from the data source about the prevalence of this practice. The provided physician identifiers are encrypted during HCUP processing.

Florida

In Florida two types of physician identifiers are available:

Attending physician is provided in MDNUM1_S and
Operating physician is provided in MDNUM2_S.

Physician identification numbers may be used to track physicians within and across hospitals. Florida reports state license numbers for the physician identifiers. During HCUP processing, physician identifiers were encrypted.

Kentucky

Beginning in 2017, Kentucky replaced the two consulting practitioner NPI numbers by the referring practitioner NPI (HCUP MDNUM3) and the patient's family practitioner NPI (HCUP MDNUM4).

Beginning in 2012, Kentucky supplies two additional consulting practitioner NPI numbers that are saved as HCUP data element MDNUM3 and MDNUM4.

Beginning October 2009, only NPIs accepted as valid IDs for both facilities and clinicians.

In Kentucky two types of physician identifiers are available:

Attending physician is provided in MDNUM1_S and
Physician that performed the primary procedure is provided in MDNUM2_S.

Physician identification numbers may not accurately track physicians within and across hospitals. Kentucky collects two different types of physician identifiers, National Provider Identifier (NPI) and state license numbers.

Maryland

Beginning in 2009, MDNUM1 includes operating physician NPI. Physician identification numbers can be used to track physicians within and across hospitals.

Prior to 2009, Maryland reported a state license number assigned by MedChi, The Maryland State Medical Society. This is now included in MDNUMOTHER1. The provided physician identifiers are encrypted during HCUP processing.

Beginning in 2007, Maryland included the records from all other outpatients, Greenbaum cancer center, and UMMS shock trauma in the unified AS and ED outpatient data file. The inclusion of these new records resulted in a large increase in the frequency of MDNUM1.

From 2003 - 2005 physician identifiers were encrypted by the state of Maryland prior to submission to HCUP.

New Jersey

Beginning in 2017, four types of physician identifiers are available:

Attending physician is provided in MDNUM1_S,
Operating physician is provided in MDNUM2_S,
Other operating physician is provided in MDNUM3_S,
Rendering physician is provided in MDNUM4_S

Physician identification numbers may not accurately track physicians within and across hospitals. During HCUP processing, physician identifiers are encrypted. The coding of the physician identification number varies across years:

Year	Physician Identifier
1988-93	New Jersey state license numbers
1994-95	Universal Physician Identification Numbers (UPINs)
1996-2008	New Jersey state license numbers.
Beginning in 2008	New Jersey National Provider Identifiers (NPIs)

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Central Distributor SASD: Description of Data Elements