# Presentation: 763993

## From ICD-9 to ICD-10: Evaluating the Impact for Healthy People 2010 Manon Boudreault, M.P.H.

**From ICD-9 to ICD-10: Evaluating the Impact for Healthy People 2010**** ****Manon Boudreault, M.P.H.**

**National Center for Health Statistics**

- Healthy People 2010

## International Classification of Diseases (ICD) History

- Since 1900,  ICD revised about every 10-20 years
**All revisions have had an impact on comparability**
- Variations in statistics due to differing coding rules used rather than a change in disease entity

- Healthy People 2010

## History....

- Beginning with deaths occurring in 1999, ICD-10 implemented
- Many systematic differences between  ICD-9 and ICD-10
- Between 1979 and 1998, ICD-9 in use

- Healthy People 2010

## Major  Differences in ICD-10:

- Rules for coding and selecting underlying cause of death have changed
- Greater detail about the type or site of the disease (from about 5,000 to 8,000 categories )
- An increased number of perinatal codes

- Healthy People 2010

## Major differences between ICD-9 and ICD-10 ...

- Chapters have been added and rearranged
- Cause-of-death titles have been changed and regrouped
- Alphanumeric codes

- Healthy People 2010

## Cause-Specific HP2010 Mortality Objectives

- About 40 objectives, most use the National Vital Statistics System as data source

- Healthy People 2010

## Baseline History

***Baseline data were initially classified and coded to:***
- 	World Health Organization’s Ninth Revision of the International Classification of Diseases
- 				 **(ICD-9)**
***Used by virtually all countries to code and classify causes of death***

- Healthy People 2010

## Same death certificates coded to each ICD version

Comparability Ratio (derived from dual classification): 

ICD-10 coded deaths
     divided by 
 ICD-9 coded deaths

May be able to adjust older data (total) with comparability ratio 

**Comparability Ratio (derived from dual classification)**:
**ICD-10 coded deaths**
**     ****divided by **
** ****ICD-9 coded deaths**
- May be able to adjust older data (total) with comparability ratio

**Comparability Study:**
**Measure Effect of Revision**

- Healthy People 2010

## Comparability Ratio 

- D**i,ICD-10**
- D**i,ICD-9**

**Measures discontinuity related solely to a revised ICD**

- C**i **** ****=**

## HP2010 Selected Estimated CRs* 

| 
Obj. No. | 
Cause | Same Deaths coded to ICD-10  | Same Deaths coded to ICD-9 | CR=
(ICD-10 divided by ICD-9) | 
  95% CI  |
| --- | --- | --- | --- | --- | --- |
| 13-14 | HIV |   12,765 |  11,150 |   1.14 |  (1.14, 1.15) |
| 16-1f | Birth Defects |     5,950 |    7,025 |     .8470 | (.8362, .8577) |
| 24-1 | Asthma
(all ages) |     4,217 |    4,718 |     .8938 | (.8819, .9057) |
| 26-3 | Drug-induced |     1,158 |        969 |   1.195 | (1.15, 1.24) |

- *Source: National Vital Statistics System-Mortality, NCHS (Preliminary data),  Comparability Ratio (CR) calculated using large sample of 1996 deaths, except for  HIV deaths (1998 deaths)

- Healthy People 2010

## Comparability Ratio (CR) ...

- Currently available for objectives where data source is the National Vital Statistics System-Mortality
- Where HP2010  ICD-9 codes are different, CRs have been calculated in a separate HP2010 report
- Is not appropriate to apply to data for objectives that use “multiple-cause-of-death” (e.g., diabetes)

- Healthy People 2010

## Comparability-Modified Deaths (or Rate)

**D****i,ICD-9**= **D****i,ICD-9**** **     **C****i**

**CM**

## Comparability Ratio CAUTION!!!!

- CR of 1 does not necessarily mean cause of death was totally unaffected by revision
- Unknown if appropriate to use on age-, race-, sex-, or State-specific mortality data
- In theory CRs could be applied to subgroups, in practice there are differences in cause-of-death distribution

- Healthy People 2010

## HP 2010 Steering Committee Response

- Unanimous vote to change baseline years for cause-specific mortality objectives to 1999
- Data years will be based on the same classification system (ICD-10)
- 1997 or 1998 (primarily) baselines replaced

- Healthy People 2010

## Effect on 2010 Targets	

- Baseline revisions were minor
- No targets were changed at the time baselines were changed

- Healthy People 2010

## Other HP2010 Mortality Sources

- U.S. Renal Data System ***(obj. 4-2)***
- Census of Fatal Occupational Injuries ***(obj. 20-01)***
- Fatality Analysis Reporting System ***(obj. 15-15b, 15-16, 26-1)***
- National Surveillance System for Pneumoconiosis                 ***(obj. 20-04)***

- Healthy People 2010

## Other HP2010 Mortality Data Sources 

- Baseline evaluations, in process now
- Case-by-case basis,
- may not use ICD coding solely in their identification

- Healthy People 2010

## From ICD-9 to ICD-10: Impact on HP2010 data 

- Most HP2010 cause-specific mortality objectives baselines changed
- Some groupings of death codes changed (noted in Tracking HP2010, operational definitions)
- Food allergy deaths –anaphylaxis  **(obj. 10-4) now measurable with ICD-10, specific codes**

- Healthy People 2010

## Other Vital Statistics ChangesImpact on HP2010 data 

**Upcoming certificate changes:**
**More complete race data expected**
-  **Some objectives will become measurable**:
-     Gestational diabetes (Objective 5-08)
- 	 Recommended weight gain during pregnancy       (Objective 16-12)

- Healthy People 2010

## For More Information On..

_**Comparability  ICD-9/10**_... Session 24..next      Concurrent Session  ...Diplomat Room
_**Comparability report**_
-  http://www.cdc.gov/nchs/products/pubs/pubd/nvsr/49/49-12.htm
_**Mortality Database**_... Session 38 ...Wednesday...Ambassador Ballroom
_**Natality Data Files**_... Session 42
-   ...Wednesday...Congressional Room

- Healthy People 2010