CDC Site Visit at EmoryCHD Surveillance

Cooperative Agreement

Prevalence Estimates

September 25, 2013

Carol Hogue, PhD, MPHCheryl Raskind-Hood, MS, MPH

Overview of General Prevalence Estimates

• 5 counties* within Metropolitan Atlanta– Population in 2010, ages 18 – 64: ~ 3 million**– 51% non-Hispanic White, 40% non-Hispanic Black– Living in same house > 1 year ~ 80%

• Resident who meets case definition with at least one encounter , 2008-2010– Hospital– Outpatient clinic– Medicaid (ResDAC)

• Presumed alive on January 1, 2010 and in age range (11-64)– GA Vital Records (Mortality 2008 – 2010)

* The five counties are within the Metropolitan Atlanta area and include Fulton, Cobb, Dekalb, Gwinnett, & Clayton.** U.S. Census 2010.

Map of Five Counties

Planned Strategy1: Population-Based Estimate

MACDP Not Linked to Data Sources includes GA Vital Records

• Hospitals and Clinics Included– Emory Healthcare: Emory HC (EHC)– Children’s Healthcare of Atlanta: CHOA– Sibley Heart Center: Sibley– Grady Health– Selected private providers:

• Pediatric Cardiology Services (PCS)

• To-date: Deduplicated CHOA & Sibley (2008-2010)– Merged by Last Name, First Name, DOB, Sex & County – Retained all CHD Dx Codes– ~4700 after adolescent merge– Few county differences

• Use of LexisNexis for validation

Data Sources for Population-based Prevalence

Variables Used to Link Various Data Sources

VARIABLES MACDP MEDICAIDCLINICAL

DBsVITAL

RECORDS

SSN - encrypted* x -

DOB x x x x

GENDER x x x x

RACE x x x xPROVIDER ID - x x x

Dx CODES ICD-9 ICD-9 ICD-9 ICD-10 NAME(LAST & FIRST)

withheld x x x

* May receive SSN to Bene_ID crosswalk from ResDAC

DATA SOURCES

Linkage for Population-based CHD Adolescents & Adults

GA Death Records

2008-2010

Emory HC2008-2010

Constrain to specific vars and remove

PHI

Sibley 2008-2018

Grady Health2008-2010

ResDAC2008-2009

Select Private Providers

2008-2018

Adult CHD Dataset

Step 4. Upload limited dataset to CDC via SAMS.

Step 3. Create limited datasets with specific core vars & PHI removed.

Step 2. Create datasets & identify survivors & non-survivors.

Adolescent& Adult

CHD Datasets

Step 1. Link GA death records to sources to determine survivors. Deduplicate.

CHOA2008-2018 Adolescent

CHD Dataset

Adolescent& Adult

CHD Datasets

Adolescent& Adult

CHD Datasets

Deduplicating & Matching Protocol

• Sibley• CHOA• Emory Clinics*• Emory Hospitals• Medicaid (ResDAC)• Others as Available

* Including archived Heart Failure database at Emory HC.

Used as example for all datasets

Deduplicated patients

SIBLEY

Flowchart: Deduplicating Adolescent EHC Clinic Datasets

Sibley extracted Name, DOB, Gender

& CHD ICD-9s for 2008-2010

CHOA 1 CHOA 2

Cross-walked county in by zip;

Concatenated multiple rows into a single row

for each patient

Sibley extracted Name, DOB, Gender

& CHD ICD-9s for 2008-2010

CHOA extracted Name, DOB, Gender

& CHD ICD-9s for 1/1/2008-4/30/2009

Concatenated multiple rows into a single row

for each patient

De-duplicate patients

CHOA extracted Name, DOB, Gender

& CHD ICD-9s for 5/1/2009-12/31/2010

Concatenated multiple rows into a single row

for each patient

De-duplicate patients

Merge & de-duplicate both datasets

Merge & de-duplicate patients

Five-county EstimatesPossible Over-estimate Because:

• Multiple data sources may not be completely deduplicated

• Name changes• Inaccurate county of residence coded (e.g.,

Grady free clinics serve only Fulton & DeKalb residents)

• Imprecision of some ICD-9CM codes / diagnoses

• Persons living with CHDs may not access the healthcare system in time frame (2008-2010) (clinical data supports this)

• You would think that • those with mild to moderate CHD defects would

be less likely to access care, BUT not so• Those with unsuccessful surgeries would be less

likely to access care, BUT according to clinical data, the complex severe defects are equally at risk (25%)

• Imprecision of some ICD9-CM codes / diagnoses

• Missing the uninsured

Five-county EstimatesPossible Under-estimate Because:

Population-based EstimateAdolescent & Adult CHD in Five-Counties:

Issues and Limitations

1. Not an issue -> Moved out of state before 20082. Data errors leading to non-match, e.g.,

incomplete dates, misspelled names, changed names (less an issue if MACDP is included in matching process)

3. Didn’t seek care in Georgia during 2008-20104. Received care outside of data sources

Should We Add 41 Counties?

Map of 46 counties

Augusta

Atlanta

Should We Add 41 Counties?

• Arguments in favor of including them– Additional data collection effort is minimal– Clinical Penetration in these counties are high

for our Network Consortium – Healthcare settings for the 5-county area also

serve the vast majority of the 46-county area– ResDAC will be reported for all of Georgia– Population of rural and semi-urban areas in the

South may have different CHD prevalence (e.g., because of migration closer to care)

– Different demographics for urban vs. rural outside and inside metro Atlanta limits

Should We Add 41 Counties?

• Arguments against including them– 46-county prevalence estimates will be more

affected by missing cases that are seen outside of Georgia

• ResDAC only for GA – GA residents can’t go out of state (out-of-pocket cost)

• Some specialized care in border areas in Alabama, Florida, and South Carolina

And the Answer Is. . . .?

Yes

Planned Strategy2:MACDP-based Estimate

Link MACDP to Data Sources includes NDI & GA Vital Records

Presumed ALIVE,

But NOT Found in

Lexis/Nexis

Seen in clinics & living within

5 counties

Seen in clinicsbut living outside

5 counties

Seen in MCAID within 5 counties

Seen in MCAID but living outside

the 5 counties

Seen in clinics & MCAID

& living within 5 counties

Seen in clinics & MCAID

but living outside 5 counties

CL

INIC

S

2008-2010

ME

DIC

AID

2008-2009

Relationship of Presumed MACDP Survivors to Clinical & Medicaid Datasets

Note. Encounters occurred between 2008-2010 for EHC & between 2008-2009 for Medicaid; 2010 Medicaid data available soon.

Summary of Data Sources

MACDP Medicaid Clinic records

GA death certificates

Maternal mortality

review

Ages in 2010

Born 1979-1999 (ages 11-31) Y Y Y Y Y

Born 1968-1978 (ages 32-42) Y Y Y Y Y

Born 1946-1967 (ages 43-64) Y Y Y

NO

YES

YES

NO

Remove from MACDP Survivors

Remove from MACDP Survivors

PRESUMED SURVIVORS

Original MACDP Dataset

Flowchart: To Obtain Dataset for Presumed MACDP Survivors

FOUND INGA DC ?

FOUND IN NDI ?

(To be completed by CDC contractors?)

Emory HC Deduplicated Dataset

FLOWCHART: Bringing Merged Sibley & CHOA Adolescent Dataset into CDC

for MACDP MATCHING

MACDP 1967-1999

Exact MatchWith Last Name, First Name, DOB,

& Gender

Add to repository matched file

& deduplicate

YES

NO

Matches with Additional

Approaches *

Add to repository matched file

& deduplicateYES

NO

Residual MACDP temporary file

* Protocol for additional matching approaches to be discussed with CDC & consortium partners.

DATA SOURCES

Linkage with MACDP: CHD Adolescents & Adults

GA Death Records

2008-2010

Emory HC2008-2010

Constrain to specific vars and remove

PHI

Sibley 2008-2018

Grady Health2008-2010

ResDAC2008-2009

Select Private Providers

2008-2018

MACDPwith or

without NDI

Linked MACDP Adult

CHD Dataset

Step 4. Upload limited dataset to CDC via SAMS.

Step 3. Create limited datasets with specific core vars & PHI removed.

Step 2. Create datasets & identify survivors & non-survivors.

Adolescent& Adult

CHD Datasets

Step 1. Link MACDP with GA death records & NDI to determine survivors. Merge with adult & adolescent sources. Deduplicate.

CHOA2008-2018

Linked MACDP Adolescent CHD Dataset

Adolescent& Adult

CHD Datasets

Adolescent& Adult

CHD Datasets

Remove PHI from MACDP not found in other sources.

Assumptions & Issues of MACDP Matching Process:

Multiple Reasons for Lack of Matching

1. Moved out of state before 20082. Data errors leading to non-match, e.g., incomplete

dates, misspelled names, changed names3. Didn’t seek care in Georgia during 2008-20104. Received care outside of data sources 5. Underestimate number of uninsured patients who

may have sought care elsewhere•Fulton & DeKalb covered through Grady Health•Emory HC does not turn anyone away

Note. 50-64 year olds will not be matched as they were born before the MACDP began collecting data.

What Does the Cooperative Agreement Gain with MACDP in the Emory Project?

• This is NOT a population-based prevalence estimate. It’s an estimate of MACDP survivors who are living in the 5-county area sometime in 2008-2010 and who accessed the healthcare system during that period.

• Can also be estimate of MACDP survivors who are living in GA (but outside the 5-county area) who accessed care through consortium or Medicaid.– And an estimate of survivors who didn’t “hit the system”

in Georgia.– Can also serve to help develop a ‘correction factor’ for

those who are still alive and who did not hit the HC system

Benefits of Linking MACDP Data to the Population-based Estimate

A population-based estimate allows for:• Estimating age-specific prevalence in five-county

area• Modeling the dispersion by age to estimate

MACDP movement out of area and out of the state of Georgia

• Modeling missed care between the MACDP and the population-based estimate by differences in prevalence rates by severity of diagnosis(there will be MACDP cases that did not match & some will be due to lack of accessing care during the 2008-2010 period; hypothesis - less severe cases are less likely to seek health care)

Prevalence Measures for Comparisons

• Determine age-specific prevalence (by decade) of those living inside the 5-county area sometime between 1/1/08-12/31/10

• Determine age-specific prevalence (by decade) of those living outside the 5-county area sometime between 1/1/08-12/31/10

GA Population-based• Five-County Prevalence (inside)

• 41-County Prevalence (outside)

• 46-County Prevalence

MACDP Survivors• Five-County Prevalence (inside)

• 41-County Prevalence (outside)

• 46-County Prevalence

Note. GMH & Pediatric Cardiology Services data will not be linked to MACDP per recent DUA agreement, October 2013.