Concept: Ambulatory Care Sensitive (ACS) Conditions

 Printer friendly

Concept Description

Last Updated: 2013-11-19

Introduction
    This concept defines Ambulatory Care Sensitive (ACS) Conditions and describes how this measures has been used in MCHP research.

    Billings et al. (1993) defined Ambulatory Care Sensitive (ACS) Conditions as a set of 28 medical conditions/diagnoses "for which timely and effective outpatient care can help to reduce the risks of hospitalization by either preventing the onset of an illness or condition, controlling an acute episodic illness or condition, or managing a chronic disease or condition". In an access type of model, variation in hospitalization rates is explained by differences in access to care prior to hospitalization; these differences tend to be associated with socioeconomic status. In the Billings et al. (1993) model, a set of 28 medical conditions was developed, for which a group of physicians agreed hospital use might be reduced by timely and effective outpatient care prior to the need for hospitalization; hence, the terms "avoidable" or "preventable" hospital use (Billings et al., 1996). Appropriate prior ambulatory care could:

    • prevent the onset of an illness or condition;
    • control an acute episodic illness or condition; or
    • manage a chronic disease or condition

    The programming to define ACS conditions was thoroughly checked by several MCHP employees; it was also cross-checked against the code that Billings et al. (1993) used in their 1993 paper.

    MCHP developed specific formats that can be used in conjunction with programming for ACS conditions. See the SAS Code links below (internal access only). NOTE: The format and code available below has not been updated since August 13, 2002.
Comparison of 5- and 3-Digit Diagnoses Codes for Selected Ambulatory Care Sensitive (ACS) Conditions
    In Manitoba, ICD-9-CM codes are coded up to the 5-digit level for certain diagnoses/conditions in the Hospital Discharge Abstracts data, but only at the 3-digit level in the Medical Services / Physician Claims data. In Roos LL et al. (2005), they compared 3-digit ICD-9-CM codes in the abstract data from 1998 - 2000 with the diagnoses codes suggested by Billings et al. (1993,) in order to analyze the difference between the total number of codes that would be reported for ACS conditions in Manitoba data.

    The comparison found that twelve relatively common ACS conditions can be specified almost completely on the basis of the 3-digit ICD-9-CM codes. The conditions are: asthma, angina, pelvic inflammatory disease, gastroenteritis, congestive heart failure, severe ear-nose-throat (ENT) infections, epilepsy, bacterial pneumonia, tuberculosis (pulmonary and other), iron deficiency anemia in children up to 5 years of age, cellulitis, and dental conditions.
    The following table lists the twelve ACS Conditions, any exclusions that are applied to the conditions, the ICD-9-CM codes used by Billings et al. (1993) and the 3-digit codes applied in Roos LL et al. (2005).
    ACS Conditions Exclusions Codes Using Billings et al. Definitions Codes Using 3-digit Adaptations
    Asthma None 493 493
    Angina Exclude cases with a surgical procedure 411.1, 411.8, 413 411, 413
    Pelvic inflammatory disease Exclude cases with a hysterectomy procedure 614 614
    Gastroenteritis None 558.9 558
    Congestive heart failure Exclude cases with a surgical procedure 402.01, 402.11, 402.91, 428, 518.4 428, 518
    Severe ENT infections Exclude otitis media (382) cases with a myringotomy procedure 462, 463, 465, 472.1, 382 462, 463, 465, 472, 382
    Epilepsy None 345 345
    Bacterial pneumonia Exclude cases with a secondary diagnosis of sickle cell or patient age less than 2 months old 481, 482.2, 482.3, 482.9, 483, 485, 486 481, 482, 483, 485, 486
    Pulmonary/other tuberculosis None 011 011
    Iron deficiency anemia Exclude cases where patient is greater than 5 years old 280.1, 280.8, 280.9 280
    Dental conditions None 521, 522, 523, 525, 528 521, 522, 523, 525, 528
    Cellulitis Exclude cases with a surgical procedure, except incision of skin and subcutaneous tissue (86.0) when listed as only procedure 681, 682, 683, 686 681, 682, 683, 686

    See below for the SAS programming code (internal access only) used to extract this comparative information.

    The following table lists the numbers and percentage difference reported for each method for each of the twelve ACS conditions.

    ACS Conditions * N Using
    Billings et al.
    Definitions
    **
    N Using
    3-digit
    Adaptations
    % Increase
    Using 3-digit
    Adaptations
    Asthma
    4,115
    4,115
    0.0%
    Angina
    4,998
    5,050
    1.0%
    Pelvic inflammatory disease
    1,409
    1,409
    0.0%
    Gastroenteritis
    2,959
    2,993
    1.1%
    Congestive heart failure
    9,759
    10,582
    8.4%
    Severe ENT infections
    2,451
    2,487
    1.5%
    Epilepsy
    825
    825
    0.0%
    Bacterial pneumonia
    11,906
    12,036
    1.1%
    Pulmonary/other tuberculosis
    258
    258
    0.0%
    Iron deficiency anemia ***
    113
    114
    0.9%
    Dental conditions
    1,509
    1,509
    0.0%
    Cellulitis
    3,547
    3,547
    0.0%
    TOTALS
    18,158
    18,289
    Notes to Table
    * Diagnoses are ordered according to the degree of consensus among three panels reported by Brown et al. (2001). The top five diagnoses in this table were identified by all panels as ambulatory care sensitive.

    ** Billings et al. (1993) suggest 4-digit definitions for several conditions. Some 5-digit codes were used to specify congestive heart failure.

    *** Iron deficiency anemia in children up to 5 years of age
ICD-9-CM and ICD-10-CA / CCI Codes for ACS Conditions / Diagnoses
    In Fransoo et al. (2009) and (2013), they investigated hospitalization rates for ACS conditions and reported on the findings. In both RHA Atlas deliverables, the Hospital Abstracts data was reviewed and the following ICD-9-CM and ICD-10-CA / CCI codes were used to identify 25 ACS conditions:
    1. Congenital Syphilis: ICD-9-CM code 090; ICD-10-CA code A50 (newborns only)
    2. Immunization-Related and Preventable Conditions: ICD-9-CM codes 033, 037, 045, 390, 391; ICD-10-CA codes A35, A37, A80, I00, I01 (also including hemophilus meningitis for children ages 1-5 only, ICD-9-CM code 320.0; ICD-10-CA code G00.0)
    3. Epilepsy: ICD-9-CM code 345; ICD-10-CA codes G40, G41
    4. Convulsions: ICD-9-CM code 780.3; ICD-10-CA code R56
    5. Severe ENT Infections: ICD-9-CM codes 382, 462, 463, 465, 472.1; ICD-10-CA codes H66, J02, J03, J06, J312 (cases of otitis media, ICD-9-CM code 382; ICD-10-CA code H66, with a procedure code for myringotomy with insertion of tube are excluded, ICD-9-CM procedure code 20.01; CCI code 1.DF.53.JA-TS)
    6. Pulmonary Tuberculosis: ICD-9-CM code 011; ICD-10-CA codes A15.0, A15.1, A15.2, A15.3, A15.7, A15.9, A16.0, A16.1, A16.2, A16.7, A16.9
    7. Other Tuberculosis: ICD-9-CM codes 012-018; ICD-10-CA codes A15.4, A15.5, A15.6, A15.8, A16.3, A16.4, A16.5, A16.8, A17, A18, A19
    8. Chronic Obstructive Pulmonary Disease (COPD): ICD-9-CM codes 491, 492, 494, 496; ICD-10-CA codes J41, J42, J43, J44, J47 (also included in 2005/06 are patients with a primary diagnosis of acute lower respiratory infection, ICD-10-CA codes J10.0, J11.0, J12-J16, J18, J21, J22, and a secondary diagnosis of COPD with acute lower respiratory infection, ICD-10-CA code J44)
    9. Acute Bronchitis: (only included if a secondary diagnosis of COPD is also present, diagnosis codes as above), ICD-9-CM code 466.0; ICD-10-CA code J20
    10. Bacterial Pneumonia: ICD-9-CM codes 481, 482.2, 482.3, 482.9, 483, 485, 486; ICD-10-CA codes J13, J14, J15.3, J15.4, J15.7, J15.9, J16, J18 (patients with a secondary diagnosis of sickle-cell anemia, ICD-9-CM code 282.6; ICD-10-CA codes D57.0, D57.1, D57.2, D57.8, and patients less than two months of age are excluded)
    11. Asthma: ICD-9-CM code 493; ICD-10-CA code J45
    12. Congestive Heart Failure (CHF): ICD-9-CM codes 402.01, 402.11, 402.91, 428, 518.4; ICD-10-CA codes I50, J81 (patients with certain cardiac procedures coded are excluded, ICD-9-CM procedure codes 36.01, 36.02, 36.05, 36.1, 37.5, 37.7; CCI codes 1.HB.53, 1.HB.54, 1.HB.55, 1.HD.53, 1.HD.54, 1.HD.55, 1.HZ.53, 1.HZ.55, 1.HZ.85, 1.IJ.50, 1.IJ.57.GQ, 1.IJ.76)
    13. Hypertension: ICD-9-CM codes 401.0, 401.9, 402.00, 402.10, 402.90; ICD-10-CA codes I10.0, I10.1, I11 (patients with certain cardiac procedures coded are excluded, procedure codes as in CHF)
    14. Angina: ICD-9-CM codes 411.1, 411.8, 413; ICD-10-CA codes I20, I23.82, I24.0, I24.8, I24.9 (patients with any surgical procedure coded are excluded)
    15. Cellulitis: ICD-9-CM codes 681, 682, 683, 686; ICD-10-CA codes L03, L04, L08, L44.4, L88, L92.2, L98.0, L98.3 (patients with any surgical procedure coded are excluded, except for incisions of skin and subcutaneous tissue, ICD-9-CM procedure code 86.0; CCI codes 1.AX.53.LA-QK, 1.IS.53.HN-LF, I.IS.53.LA-LF, 1.JU.53.GP-LG, 1.KR.53.LA-LF, 1.OA.53.LA-QK, 1.SY.53.LA-QK, 1.YA.35.HA-W1, 1.YA.35.HA-X4, 1.YA.52.HA, 1.YA.52.LA, 1.YA.55.DA-TP, 1.YA.55.LA-TP, 1.YA.56.LA, 1.YB.52.HA, 1.YB.52.LA, 1.YB.55.DA-TP, 1.YB.55.LA-TP, 1.YB.56.LA, 1.YF.35.HA-W1, 1.YF.35.HA-X4, 1.YF.52.HA, 1.YF.55.DA-TP, 1.YF.55.LA-TP, 1.YF.56.LA, 1.YG.52.HA, 1.YG.52.LA, 1.YG.55.DA-TP, 1.YG.55.LA-TP, 1.YG.56.LA, 1.YR.52.HA, 1.YR.52.LA, 1.YR.56.LA, 1.YS.35.HA-W1, 1.YS.35.HA-X4, 1.YS.52.HA, 1.YS.52.LA, 1.YS.55.DA.TP, 1.YS.55.LA-TP, 1.YS.56.LA, 1.YT.35.HA-W1, 1.YT.35.HA-X4, 1.YT.52.HA, 1.YT.52.LA, 1.YT.55.DA-TP, 1.YT.55.LA-TP, 1.YT.56.LA, 1.YU.52.HA, 1.YU.52.LA, 1.YU.55.DA-TP, 1.YU.55.LA-TP, 1.YU.56.LA, 1.YV.35.HA-W1, 1.YV.35.HA-X4, 1.YV.52.HA, 1.YV.52.LA, 1.YV.55.DA-TP, 1.YV.55.LA-TP, 1.YV.56.LA, 1.YW.52.HA, 1.YW.52.LA, 1.YW.55.DA-TP, 1.YW.55.LA-TP, 1.YW.56.LA, 1.YX.52.HA, 1.YX.52.HA-AV, 1.YX.52.LA, 1.YX.56.LA, 1.YZ.35.HA-W1, 1.YZ.35.HA-X4, 1.YZ.52.HA, 1.YZ.52.LA, 1.YZ.55.DA-TP, 1.YZ.55.LA-TP, 1.YZ.56.LA)
    16. Diabetes: ICD-9-CM codes 250.0, 250.1, 250.2, 250.3, 250.8, 250.9; ICD-10-CA codes E10.1, E10.6, E10.7, E10.9, E11.0, E11.1, E11.6, E11.7, E11.9, E13.0, E13.1, E13.6, E13.7, E13.9, E14.0, E14.1, E14.6, E14.7, E14.9
    17. Hypoglycemia: ICD-9-CM code 251.2; ICD-10-CA codes E16.0, E16.1, E16.2
    18. Gastroenteritis: ICD-9-CM code 558.9; ICD-10-CA codes K52.2, K52.8, K52.9
    19. Kidney/Urinary Infections: ICD-9-CM codes 590, 599.0, 599.9; ICD-10-CA codes N10, N11, N12, N13.6, N15.1, N15.8, N15.9, N16.0-N16.5, N28.83-N28.85, N36.9, N39.0, N39.9
    20. Dehydration/Volume Depletion: ICD-9-CM code 276.5; ICD-10-CA code E86
    21. Iron Deficiency Anemia: ICD-9-CM codes 280.1, 280.8, 280.9; ICD-10-CA codes D50.1, D50.8, D50.9 (patients age 0-5 only)
    22. Nutritional Deficiencies: ICD-9-CM codes 260, 261, 262, 268.0, 268.1; ICD-10-CA codes E40-E43, E55.0, E64.3
    23. Failure to Thrive: ICD-9-CM code 783.4; ICD-10-CA code R62 (patients less than one year of age only)
    24. Pelvic Inflammatory Disease: ICD-9-CM code 614; ICD-10-CA codes N70, N73, N99.4 (female patients only, patients with a hysterectomy procedure coded are excluded, ICD-9-CM procedure codes 68.3-68.8; CCI codes 1.RM.87, 1.RM.89, 1.RM.91, 5.CA.89.CK, 5.CA.89.DA, 5.CA.89.GB, 5.CA.89.WJ, 5.CA.89.WK)
    25. Dental Conditions: ICD-9-CM codes 521, 522, 523, 525, 528; ICD-10-CA codes K02-K06, K08, K09.8, K09.9, K12, K13

    NOTE:
    • For all ACS conditions above (except congenital syphilis), the ACS condition must be coded as the most responsible diagnosis and the patient, unless otherwise noted, must be between the ages of 0-74.
    • Low rates of hospitalizations for ACS conditions can be used as indicators of access to good quality primary care.
    • This list of 25 conditions is an adaptation of the original work by Billings et al. (1993). In this list, convulsions are combined into one category, regardless of age; all types of diabetes are combined into one category; and a category identifying acute bronchitis has been added.

    For more information from the two RHA Atlas deliverables, including key findings; comparison to other findings; and graphs by RHA, RHA Districts and Winnipeg Neighbourhood Clusters, please read:

Related concepts 

Related terms 

References 

  • Billings J, Zeitel L, Lukomnik J, Carey TS, Blank AE, Newman L. Impact of socio-economic status on hospital use in New York City. Health Affairs (Millwood) 1993;12(1):172-173. [Abstract] (View)
  • Billings J, Anderson GM, Newman LS. Recent findings on preventable hospitalizations. Health Aff (Millwood) 1996;15(3):239-249. [Abstract] (View)
  • Bindman AB, Grumbach K, Osmond D, Komaromy M, Vranizan K, Lurie N, Billings J, Stewart A. Preventable hospitalizations and access to health care. JAMA 1995;274(4):305-311. [Abstract] (View)
  • Blustein J, Hanson K, Shea S. Preventable hospitalizations and socioeconomic status. Health Aff (Millwood) 1998;17(2):177-189. [Abstract] (View)
  • Brown AD, Goldacre MJ, Hicks N, Rourke JT, McMurtry RY, Brown JD, Anderson GM. Hospitalization for ambulatory care-sensitive conditions: a method for comparative access and quality studies using routinely collected statistics. Can J Public Health 2001;92(2):155-159. [Abstract] (View)
  • Casanova C, Starfield B. Hospitalizations of children and access to primary care: a cross-national comparison. Int J Health Serv 1995;25(2):283-294. [Abstract] (View)
  • Fransoo R, Martens P, Burland E, The Need to Know Team, Prior H, Burchill C. Manitoba RHA Indicators Atlas 2009. Winnipeg, MB: Manitoba Centre for Health Policy, 2009. [Full Report] [Summary] [Data extras] (View)
  • Fransoo R, Martens P, The Need to Know Team, Prior H, Burchill C, Koseva I, Bailly A, Allegro E. The 2013 RHA Indicators Atlas. Winnipeg, MB: Manitoba Centre for Health Policy, 2013. [Full Report] [Summary] [Data extras] (View)
  • Komaromy M, Lurie N, Osmond D, Vranizan K, Keane D, Bindman AB. Physician practice style and rates of hospitalization for chronic medical conditions. Med Care 1996;34(6):594-609. [Abstract] (View)
  • Pappas G, Hadden WC, Kozak LJ, Fisher GF. Potentially avoidable hospitalizations: inequalities in rates between US socioeconomic groups. Am J Public Health 1997;87(5):811-816. [Abstract] (View)
  • Parchman ML, Culler S. Primary care physicians and avoidable hospitalizations. J Fam Pract 1994;39(2):123-128. [Abstract] (View)
  • Roos LL, Walld R, Uhanova J, Bond R. Physician visits, hospitalizations, and socioeconomic status: ambulatory care sensitive conditions in a Canadian setting. Health Serv Res 2005;40(4):1167-1185. [Abstract] (View)
  • Roos NP, Fransoo R, Bogdanovic B, Friesen D, MacWilliam L. Issues in the Management of Specialist Physician Resources for Manitoba. Winnipeg, MB: Manitoba Centre for Health Policy and Evaluation, 1997. [Full Report] [Summary] (View)
  • Roos NP, Mustard CA. Variation in health and health care use by socioeconomic status in Winnipeg, Canada: does the system work well? Yes and no. Milbank Q 1997;75(1):89-111. [Abstract] (View)
  • Weissman JS, Gatsonis C, Epstein AM. Rates of avoidable hospitalization by insurance status in Massachusetts and Maryland. JAMA 1992;268(17):2388-2394. [Abstract] (View)

Keywords 

  • Health Measures
  • health status indicators
  • hospitalization


The best way to keep up to date with what's happening at MCHP is to subscribe to our news list. We'll periodically send you notice of recently released reports, events, and other material from MCHP. If you're interested, please enter your email address in the space below. You can update your information or unsubscribe at any time.



* Email
* First Name
* Last Name
* Business
* = Required Field
This email list is privately maintained for MCHP by iContact.

Find us. Twitter and Facebook.

MCHP on Twitter MCHP on Facebook