1. Public Aggregate Reporting – DHCS Business Reports Overview
Linette Scott, MD, MPH
Chief Medical Information Officer, DHCS
July 1, 2015

2. Public Aggregate Reporting for DHCS Business Reports (PAR-DBR)
HIPAA Standard for De-identification
Overview of the PAR-DBR
Steps of the PAR-DBR

3. HIPAA Standard for De-identification

4. Health Insurance Portability and Accountability Act (HIPAA)
HIPAA standard for de-identification of protected health information:
“Health information that does not identify an individual and with respect to which there is no reasonable basis to believe that the information can be used to identify an individual is not individually identifiable health information”
DHCS is a HIPAA Covered Entity
identification/guidance.html

5. HIPAA De-identification Standard
Two methods described in the standard:
Safe Harbor
18 identifiers of the individual or of relatives, employers, or household members of the individual must be removed
In the context of other publicly available information
Expert Determination

6. HIPAA Safe Harbor Names
All geographic subdivisions smaller than a state, including street address, city, county, precinct, ZIP code, and their equivalent geocodes, except for the initial three digits of the ZIP code if, according to the current publicly available data from the Bureau of the Census:
The geographic unit formed by combining all ZIP codes with the same three initial digits contains more than 20,000 people; and
The initial three digits of a ZIP code for all such geographic units containing 20,000 or fewer people is changed to 000
All elements of dates (except year) for dates that are directly related to an individual, including birth date, admission date, discharge date, death date, and all ages over 89 and all elements of dates (including year) indicative of such age, except that such ages and elements may be aggregated into a single category of age 90 or older

7. HIPAA Safe Harbor Cont. Telephone numbers Fax numbers Email addresses
Social security numbers
Medical record numbers
Health plan beneficiary numbers
Account numbers
Certificate/license numbers
Vehicle identifiers and serial numbers, including license plate numbers
Device identifiers and serial numbers
Web Universal Resource Locators (URLs)
Internet Protocol (IP) addresses
Biometric identifiers, including finger and voice prints
Full-face photographs and any comparable images
Any other unique identifying number, characteristic, or code

8. What Usually Leads to Expert Determination?
Time
The time period is less than a year
Geography
Less than statewide
Other
Rare diagnosis
Specific combinations of variables

9. Expert Determination Apply statistical or scientific principles
Very small risk that the anticipated recipient could identify an individual
Documents the methods and results of the analysis that justify such determination
-identification/guidance.html#standard

10. Overview of the PAR-DBR

11. Purpose of the PAR-DBR
Establish guidelines to be used for reports and documents generated by DHCS programs for public release that include data (tables, charts, graphics)
Create consistency in the analysis and presentation of data in reports and documents
Protect confidentiality of personal data held by DHCS
Compliance with laws that govern data release

12. Public Aggregate Reporting DHCS Business Reports
These Guidelines provide a method and process for Expert Determination
Key Steps:
Evaluate the Numerator
Evaluate the Denominator
Use the Publication Scoring Criteria
Suppress data that has higher risk
Departmental document review processes

13. Public Aggregate Reporting

14. A Table with Suppressed Data

15. STEPS for the Par-dbr

16. Defining Table Cell
The Cells in the table are the boxes that have values in them, as opposed to the row and column headers Table Cell
Year
# of Medi-Cal Members in Fee For Service (in thousands)
# of Medi-Cal Members in Managed Care (in thousands)
2012
2,775
4,853
2011
3,067
4,527
- Data in the Table

17. Defining Numerator & Denominator
Numerator – number of events with the characteristics of the given row and column Denominator – the population from which the events arise
Year
# of Medi-Cal Members in Fee For Service (in thousands)
# of Medi-Cal Members in Managed Care (in thousands)
2012
2,775
4,853
2011
3,067
4,527
Numerator
# of Medi-Cal Members in Fee For Service (in thousands)
2,775
Denominator
# Medi-Cal Members in (in thousands)
7,628
- Data in the Table

18. A stepwise decision tree to assess aggregate data for de-identification Serves as a tool and guideline for the Expert Determination

20. Reporting Assessment Decision Tree Steps 1 & 2
A minimum cell size is set for the Numerator
A minimum value is set for the Denominator
Both the minimum cell size for the numerator and denominator must be met
DHCS has identified a minimum value of 11 for the numerator rule and a minimum value for the denominator 20,000.
Both conditions must be met to release the data in the table cell, otherwise proceed to Step 3

21. Step 3 – Apply Publication Scoring Criteria to assess risk
Step 4 – Suppress Small Cells and Complimentary Cells if score is greater than 12

22. Common Public Reporting Variables
A symbol standing in for an unknown numerical value in an equation
Common variables in health data aggregation:
Age
Sex
Race
Ethnicity
Time
Geography (State, County, Medical Service Study Area, ZIP Code)
Diagnosis/Condition
Provider (Type, Specialty, Location)

23. Variables - Ranges
A given variable my have different ranges assigned to it
Ranges assigned to the variable may be defined many ways
Example – Age Groupings
0-10, 11-20, 21-30, etc. (years old) … provides equal groupings, commonly used, may not apply to a particular program
0-4, 5-11, 12-18, (years old) … correlates to school environments: pre-school, elementary, junior high/high school, post-school

24. Publication Scoring Criteria – Step 3
Variable
Characteristics
Score
Sex
Male or Female +1
Age Range
>10-year age range +2
6-10 year age range +3
3-5 year age range +5
1-2 year age range +7
Race Group
White, Asian, Black
Detailed Race
Hispanic Ethnicity
yes or no
Detailed ethnicity
Language Spoken
English, Spanish, Other Language

25. Publication Scoring Criteria – Cont.
Variable
Characteristics
Score
Events
1000+ events in a specified population +2
 (Numerator)
events +3
11-99 events +5
<11 events +8
Geography
State or geography with population >2,000,000 -5
Population 560, ,000,000 -3
Population 20, ,000
Population ≤ 20,000
Data Year
5 years aggregated
2-4 years aggregated
1 year (e.g., 2001)
Bi-Annual +4
Quarterly
Monthly +7

26. Compiling the Score
Release Scoring Criteria approximately quantifies two re-identification risks:
size of potential population
variable specificity
Add the score assigned to each variable characteristic:
If the score is more than 12, cell sizes must be 11 or more before releasing data

27. Suppression – Step 4 Complimentary Cells
Any time a single cell could be calculated based on row or column totals when it is suppressed, then additional cells in that row and/or column will also need to be suppressed
The total value of the cells suppressed should be 11 or more
Additional Aggregation Examples
Extend the time period included
Group regional geography
Goal – large enough groups that suppression is no longer necessary

28. Aggregate Variables - Examples
Higher Aggregation
Lower Aggregation
Age Groups: 0-21, 22-64, 65 and older
Ethnicity: Hispanic or Not Hispanic
Geography: Medical Service Study Areas (542 in CA)
Time: three years
Diagnosis: Diagnosis Related Groups (DRGs), Episode Grouper
Age Groups: one year increments (1, 2, 3, etc.)
Race: White, Black, American Indian, Asian Indian, Chinese, Filipino, Japanese, Korean, Vietnamese, Native Hawaiian, Guamanian, Samoan, Other
Geography: ZIP Code (2,591 in CA)
Time: monthly
Diagnosis: Specific ICD-9 Codes

29. Aggregation
To achieve a minimum number in the given cell, results are combined over the associated variable:
Geographic areas,
Multiple years, or
Subgroups (e.g., age groups)
The number of variables in a table will affect the amount of aggregation necessary
For example, if the results for a 5 year age group (ages 1-5 years of age) do not yield an adequate number of cases, then the age group is extended to cover more ages (1-10 years of age)

30. Step 5 – Approval Processes
Program Management
Expert Determination
Office of Legal Services Privacy Team
Office of Public Affairs

31. Public Aggregate Reporting for DHCS Business Reports
A multi-step process supports public reporting
Balances public reporting with protecting confidentiality
Will continue to review and revise as the data landscape changes and matures
DHCS is committed to supporting data publishing while being consistent with the HIPAA De-identification Standard

32. Thank you!