The Clinical Classifications Software (CCS) for ICD-9-CM is one in a family of databases and software tools developed as part of the Healthcare Cost and Utilization Project (HCUP),a Federal-State-Industry partnership sponsored by the Agency for Healthcare Research and Quality. HCUP databases, tools, and software inform decision making at the national, State, and community levels.

Contents:

• Overview of CCS
• Technical Advice
• Publications Using CCS
• For More Information About CCS
• Downloading Information for CCS Software and User's Guide
• Questions?

The Clinical Classifications Software (CCS) for ICD-9-CM is a diagnosis and procedure categorization scheme that can be employed in many types of projects analyzing data on diagnoses and procedures. CCS is based on the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM), a uniform and standardized coding system. The ICD-9-CM's multitude of codes - over 13,600 diagnosis codes and 3,700 procedure codes - are collapsed into a smaller number of clinically meaningful categories that are sometimes more useful for presenting descriptive statistics than are individual ICD-9-CM codes.

For example, CCS can be used to identify populations for disease- or procedure-specific studies or to develop statistical reports providing information (such as charges and length of stay) about relatively specific conditions. CCS was formerly called the Clinical Classifications for Health Policy Research (CCHPR).

The CCS now includes categories from the Mental Health Substance Abuse Clinical Classification Software (CCS-MHSA). These categories replace the original CCS categories for mental health and substance abuse. More specifically, the CCS single-level software includes the CCS-MHSA general categories, and the CCS multi-level software includes the CCS-MHSA specific categories. For more information on the integration, please see the 2009 Software and User’s Guide.

A special archival version of the single-level CCS for diagnoses is available for users doing longitudinal analysis involving past years. This version uses the original CCS format for mental health conditions (65-75), and applies it to the latest ICD-9-CM codes. The archival tool can be found in the ASCII program files download section below.

Emtpy Categories:
Please note that CCS categories 150 and 260 do not contain any diagnosis codes at present but are valid categories. They are not in the single-level diagnosis tool or Appendix A, but appear in the User’s Guide, labels file, and the category names file.

Suicide E codes: Mechanism of Injury:
Suicide E Codes (external cause of injury codes) are assigned to CCS category 662, "Suicide and Self–Inflicted Injury". However, for users who wish to assign these E codes to a mechanism of injury CCS, an optional CCS category has been provided in the single-level diagnosis tool ($dxref 2009.csv) for each code. These optional CCS categories follow the CDC’s classification of E codes into mechanism of injury categories such as firearm or poisoning, Interested users should simply reassign suicide codes from category 662 to the optional secondary CCS categories as detailed in column five of $dxref 2009.csv. The code below gives an example of the reassignment process. Similar code can be used to reassign the CCS label:

Filename inraw "c:\tools\ccs$DXREF 2009.csv" ;
/*****************************************/
/* Make a SAS format Using the Optional */
/* Suicide Mechansism CCS Category. */
/*****************************************/v data new;
      infile inraw dsd dlm=',' end = eof firstobs=3 missover;
         input start : $char5.
              Oldccs : $char4.
              Value1 : $char70.
              Value2 : $char70.
              Label : $char4.
              Value3 : $char70.
              ;
         retain hlo "   ";
      fmtname = "$ccs" ;
      type = "   " ;
      output;

      if eof then do ;
         start = "   " ;
         vlabel = "   " ;
         hlo = "o";
         output ;
      end ;
run;
proc format cntlin = new ;
run;
/*****************************************/
/* Reassign CCS to the Optional CCS for */
/* Suicide mechanism using SAS format. */
/*****************************************/
data test;
      Set ecodedata;
      Ccs = put(ecode,$ccs.)
run;


For more information on the CCS, select to access the CCS Fact Sheet.

For downloading information, select to access the CCS Software and User's guide (which can be viewed in Portable Document Format).

This documentation contains:

• A brief description of the CCS categorization scheme
• Electronic files in ASCII format containing the translation of ICD-9-CM diagnosis and procedure codes into CCS categories.

The CCS documentation describes the electronic translation files, provides warnings about ICD-9-CM coding changes over time, and summarizes how to use the files.

For examples of how CCS has been used, see the following publications:

Ash AS, Posner MA, Speckman J; Franco S; Yacht AC; Bramwell L. Using claims data to examine mortality trends following hospitalization for heart attack in Medicare. Health Services Research, 38(5): 1253-1262(10), October 2003.

Bao Y, Sturm R. How do trends for behavioral health inpatient care differ from medical inpatient care in U.S. community hospitals? Journal of Mental Health Policy and Economics, 4: 55-63, 2001.

Bynum JP, Rabins PV, Weller W, Niefeld, M, Anderson GF, Wu AW. The relationship between a dementia diagnosis, chronic illness, Medicare expenditures, and hospital use. Journal of the American Geriatrics Society, 52(2): 187, February 2004. http://www.blackwell-synergy.com/doi/abs/10.1111/j.1532-5415.2004.52054.x

Chou L. Estimating medical costs of gastroenterological diseases. World Journal of Gastroenterology, 10(2): 273-278, January 15, 2004.

Cowen ME, Strawderman RL. Quantifying the physician contribution to managed care pharmacy expenses. A random effects approach. Medical Care, 40(8):651-61, August 2002.

Duffy, ME. The Agency for Healthcare Research and Quality: a valuable resource for evidence-based practice. Clinical Nurse Specialist, 19(3):117-120, May/June 2005.

Duffy SQ. "Substance Use and Mental Disorder Discharges from U.S. Community Hospitals in the Early 1990s, Revisited," Health Services Utilization by Individuals with Substance Abuse and Mental Disorders. December 2004. http://oas.samhsa.gov/HSR/ch3.htm. (Accessed November 17, 2005.)

Farquhar CM, Steiner CA. Hysterectomy rates in the United States 1990-1997. Obstetrics & Gynecology, 99(2): 229-234, February 2002.

Fortino A. L’Utilizzo Degli ACC (CCS) Nella Rappresentazione Della Casistica Di Ricovero Ospedaliero. Ministero della Salute - Direzione Generale della Programmazione Sanitaria.http://www.ministerosalute.it/programmazione/resources/documenti/ACC_descrizione.doc. (Accessed November 17, 2005.)

Lee BJ, Mackey-Bilaver L, Goerge RM. The Patterns of Food Stamp and WIC Participation and Their Effects on Health of Low-Income Children. Chapin Hall Center for Children at the University of Chicago.

Missouri Department of Health and Senior Services, Emergency Room MICA Statistics. http://www.dhss.mo.gov/EmergencyRoomMICA/Documentation.html. (Accessed November 17, 2005.)

Pressley JC, Barlow B. Child and adolescent injury as a result of falls from buildings and structures. Injury Prevention. 11; 267-273, 2005. http://ip.bmjjournals.com/cgi/reprint/11/5/267

Salvin, JW, Laussen, PC, Thiagarajan, RR. ECMO following cardiac surgery from the KID 2000 database. Pediatric Critical Care Medicine, 6(3):398, May 2005.

Stukenborg G, Wagner DP, Dembling BP, Connors AF. A Method for Assessing the Risk of Influenza Attributable Rehospitalization. Academy for Health Services Research and Health Policy Annual Meeting 2001 abstract. (Accessed November 17, 2005.)

Swartz SH, Cowan TM, Batista IA. Using claims data to examine patients using practice-based Internet communication: Is there a clinical digital divide? Journal of Medical Internet Research 2004; 6(1):e1. http://www.jmir.org/2004/1/e1/

Wheeler EC, Klemm P, Hardie T, Plowfield L, Birney M, Polek C, Lynch KG. Racial disparities in hospitalized elderly patients with chronic heart failure. Journal of Transcultural Nursing, 15(4): 291-297, 2004.

Williams KA, Buechner JS. "Hospitalizations for Mental Health and Substance Abuse," Health By Numbers, 5(10), October 2003. http://www.health.ri.gov/chic/statistics/hbn_oct2003.pdf. (Accessed November 17, 2005.)

Yu W, Ravelo A, Wagner T, Barnett P. The relationships among age, chronic conditions, and healthcare costs. The American Journal of Managed Care, 10:909-916, 2004.

Fact Books:

Merrill CT, Elixhauser A. Hospitalization in the United States. Rockville (MD): Agency for Healthcare Research and Quality; 2002. HCUP Fact Book No. 6; AHRQ Publication No. 05-0056. http://www.ahrq.gov/data/hcup/factbk6/

Owens PL, Thompson J, Elixhauser A, Ryan K. Care of Children and Adolescents in U.S. Hospitals. HCUP Fact Book No. 4. AHRQ Publication No. 04-0004, October 2003. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/data/hcup/factbk4/factbk4.htm

Jiang JH, Elixhauser A, Nicholas J, Steiner C, Reyes C, Bierman AS. Care of Women in U.S. Hospitals, 2000. HCUP Fact Book No. 3. AHRQ Publication No. 02-0044, October 2002. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/data/hcup/factbk3/factbk3.htm

Care of Women in U.S. Hospitals, 2000. HCUP Fact Book No. 3. AHRQ Publication No. 02-0044, October 2002. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/data/hcup/factbk3/factbk3.htm

Hospitalization in the United States, 1997. HCUP Fact Book No.1. AHRQ Publication No. 00-0031, May 2000. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/data/hcup/factbk1/

Procedures in U.S. Hospitals, 1997. HCUP Fact Book No. 2. Elixhauser A, Klemstine K, Steiner C, Bierman A. February 2001, AHRQ Publication No. 01-0016. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/data/hcup/factbk2/factbk2.htm

References from Original CCS Documentation:

Cowen ME, Dusseau DJ, Toth BG, et al. Casemix adjustment of managed care claims data using the clinical classifications for health policy research method. Medical Care, 1998, 36:1108-1113.

Duffy SQ, Elixhauser A, Sommers JP. Diagnosis and procedure combinations in hospital inpatient data. Healthcare Cost and Utilization Project (HCUP 3) Research Note 5. Rockville, MD: Agency for Health Care Policy and Research; 1996. AHCPR Pub. No. 96-0047.

Elixhauser A, McCarthy EM. Clinical classifications for health policy research, version 2: Hospital inpatient statistics. Healthcare Cost and Utilization Project (HCUP 3) Research Note 1. Rockville, MD: Agency for Health Care Policy and Research; 1996. AHCPR Pub. No. 96 0017.

Elixhauser A, Steiner CA, Whittington C, et al. Clinical classifications for health policy research: Hospital inpatient statistics, 1995. Healthcare Cost and Utilization Project, HCUP 3 Research Note. Rockville, MD: Agency for Health Care Policy and Research; 1998. AHCPR Pub. No. 98-0049.

Elixhauser A, Steiner CA. Hospital inpatient statistics, 1996. Healthcare Cost and Utilization Project (HCUP) Research Note. Rockville, MD: Agency for Health Care Policy and Research; 1999. AHCPR Pub. No. 99-0034.

CCS categories are also used in HCUPnet, an online resource for national hospital stays.

Send questions or comments to: hcup@ahrq.gov.

Shift-click from this Web page: Your browser may support loading the files for CCS and the Software and User's Guide from this Web page. To download the files from this Web page, click on the following links with the right mouse button and select "Save Link As" (Netscape) or "Save Target As" (Internet Explorer). After saving a file, find the file by using Windows® Explorer (Windows® 98/95/NT) or File Manager (Windows® 3.x) and then open it by double-clicking on it.

CCS Information

2009 CCS (ICD-9-CM) Software and User's Guide (PDF file, 143 KB)

Appendix A: Single-Level Diagnoses (txt file, 102 KB).

Appendix B: Single-Level Procedures (txt file, 38 KB).

Appendix C: Multi-Level Diagnoses (txt file, 180 KB).

Appendix D: Multi-Level Procedures (txt file, 110 KB).

CCS Category Names (Full Labels) (PDF file, 50 KB).

ASCII CCS Program Files for Use with SAS or SPSS

Single Level CCS (Zipped file, 203 KB).

Multi-Level CCS (Zipped file, 117 KB).

Archival Single-Level CCS for Diagnoses (CSV file, 825 KB).

Stata CCS Program Files

Single-Level Diagnosis CCS Categories (Zipped file, 43 KB)

Single-Level Procedures CCS Categories (Zipped file, 21 KB)

Multi-Level Diagnoses CCS Categories (Zipped file, 20 KB)

Multi-Level Procedures CCS Categories (Zipped file, 50 KB)

Questions regarding the CCS may be directed to HCUP User Support through the following channels:

• e-mail: hcup@ahrq.gov
• Phone (toll free): 1-866-290-HCUP.