Central Distributor SASD: Description of Data Elements

MDNUM4_R - Physician 4 number (re-identified)

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MDNUM4_R is an arbitrarily chosen re-identified identifier for physicians created during HCUP data processing. If the original physician identifier is based on a state license number or Universal Physician Identification Number (UPIN), then MDNUM4_R can be used to track a physician across hospitals. If the original physician identifier is based on hospital-specific identifiers, then it can only be used to track physicians within a hospital. Except in those data sources where physician license numbers are supplied, it is not known whether the physician identifier refers to individual physicians or to groups. MDNUM4_R cannot be linked to any external database in order to obtain additional physician characteristic information.Refer to state-specific notes for more information about the type of physician identifiers provided by each state.

Because of a change in the algorithm for creating a masked physician number, physicians cannot be tracked from before 2003 to after 2003. In HCUP data prior to 2003, a synthetic physician number (MDNUM4_S), created using fixed-key encryption, was available. Starting in data year 2003, a reidentification number (MDNUM4_R) was used.

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Uniform Values

Variable	Description	Value	Value Description
MDNUM4_R	Physician 4 number (re-identified)	9(n)	Physician identifier
MDNUM4_R	Physician 4 number (re-identified)	.	Missing

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State Specific Notes

District of Columbia

In data year 2018, the source data provided by the HCUP Partner was missing a leading digit from some of the physician identification numbers. This will impact the reidentified value.

In District of Columbia, four types of physician identifiers are available:

Attending physician is provided in MDNUM1
Other physician in MDNUM2
Second other physician in MDNUM3, and
Third other physician in MDNUM4.

District of Columbia provides a combination of National Provider Identifier (NPI) and Universal Physician Identification Number (UPIN).

Georgia

In Georgia four types of physician identifiers are available beginning 2008:

Attending physician is provided in MDNUM1_R,
1st other physician is provided in MDNUM2_R,
2nd other physician is provided in MDNUM3_R, and
3rd other physician is provided in MDNUM4_R.

Physician identification numbers may not accurately track physicians within and across hospitals. Prior to 2008, either the physician's state license number or the Universal Physician Identification Number (UPIN) were used to identify the physician. Beginning 2008, the national provider identification numbers (NPI) is provided. The provided physician identifiers are encrypted during HCUP processing.

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.

Attending physician is provided in MDNUM1_R and
Physician that performed the primary procedure is provided in MDNUM2_R.

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.

Oregon

In Oregon, four types of physician identifiers are available:

Attending Clinician is provided in MDNUM1,
Operating room Clinician is provided in MDNUM2,
1st Other Clinician is provided in MDNUM3, and
2nd Other Clinician is provided in MDNUM4.

MDNUM4_R was not supplied or available for 2011.

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Central Distributor SASD: Description of Data Elements