Max Rady College of Medicine

Concept: Morbidity Classification System in Children

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Concept Description

Last Updated: 2001-11-06

1 - Conceptual Framework

    Based on classifications system of childhood morbidity, a construct was developed to describe health care utilization in children (Newacheck and Starfield 1988; Starfield et al 1985; Starfield et al 1984) . Health care contacts are categorized according to the reason for health care, as follows:

    1. acute conditions,
    2. recurrent conditions,
    3. permanent conditions,
    4. perinatal conditions and
    5. preventative care.

    The classification system is a "non-categorical" approach to defining illness in children that describes elements shared by conditions, such as impact on the child's functional status or need for medical services (Newacheck and Starfield 1985; Stein et al 1993; Perrin et al 1993). This perspective enables the assessment of the burden of illness on the health care system, and of the impact of illness on the child in terms of the inconvenience and discomfort of continuous therapeutic management and contact with the health care system (Perrin et al 1993).

    Acute conditions are self-limiting conditions, or conditions which regress after treatment; they appear as single, isolated episodes of health care.

    Permanent conditions are conditions, either congenital or acquired, which would likely persist throughout childhood and/or require continuous health care, such as dependence on medications, special diet, medical technology or devices and personal assistance (Stein et al 1993).

    Recurrent conditions are conditions that result in repeated, though not necessarily regular, contact with the health care system over a 1 year period. The concept of recurrence was used to identify conditions which would potentially impact on a child's everyday activities (Perrin et al 1993).

    Perinatal conditions occur only in the newborn period.

    Visits for preventative care include health care contacts for routine examinations and vaccinations.

    This system was developed for a project by Kozyrskyj et al. (2001) prior to the John Hopkin's ACG system, which we now recommend in its place.

2 - Operational Definitions

    The classification of ICD-9 diagnosis codes into : 1) acute conditions, 2) recurrent conditions, 3) permanent conditions, 4) perinatal conditions and 5) preventative care is described in Table 1 . The operational definitions for permanent and recurrent conditions are described in further detail as follows:

    • Permanent condition

      A single physician or hospital contact (primary diagnosis only) for any 3-digit ICD-9 diagnosis code that appears in the permanent condition category, listed in Table 1A, denotes a child with a permanent condition with the following exceptions:

      1. children with AIDS are identified by the 5-digit ICD-9 diagnosis code of "0795" in any of the 16 diagnosis codes in the hospital record.

      2. asthma is categorized as a permanent condition if there were at least two health care contacts for the 3-digit ICD-9 diagnosis of "493".

      3. children with congenital malformations are identified from a review of listed 3-digit diagnoses from time of birth to 2 years of age.

    • Recurrent condition

      A single ambulatory or hospital contact (primary diagnosis only) for any 3-digit ICD-9 diagnosis code that appears in the recurrent condition category* listed in Table 1B denotes a child with a recurrent condition if any of the following conditions are met:

      1. presence of ambulatory visits, or hospital visits with LOS <=7 days, over 2 or more consecutive quarter time periods in one year.

      2. presence of ambulatory visits, or hospital visits with LOS <=7 days, over 3 non-consecutive quarter time periods in one year.

      3. occurrence of ambulatory, or hospital visits with LOS <= 7 days, in single quarter time periods only if there are no more than 3 visits in the quarter.

      4. any occurrence of a hospital visit for > 7 days.

      Note * - add acute condition category to completely enumerate all children with recurrent conditions.

Table 1. ICD-9 Diagnosis Classification System for Childhood Conditions

    Classification ICD-9-CM Diagnosis Code

    A. Permanent conditions
    AIDS [incl. HIV positive] * 042, V08, 0795
    Arthropathies (excl. infectious, joint pain) * 710, 712-718
    720-723, 725-728, 731-39, V49
    Asthma * 493
    Cardiac disease * 392-454, 456-458
    Cerebral palsy and other paralyses 342-344
    CNS disorders (excl. epilepsy, paralyses) 324-341, 347-349
    Congenital anomalies (excl. spina bifida) 740, 742-59, 771
    Cystic fibrosis and other * 277
    Diabetes Mellitus * 250
    Endocrine, other than diabetes 252-259
    Epilepsy * 345
    Gastroenteritis, colitis & malabsorption * 555-7, 579,V44
    Hematologic (sickle cell, excl, anemia) * 281-289
    Mental Retardation 317-319
    Metabolic/immune disorders * 270-3, 279
    Neoplasms * 140-215, 217-239, V10
    Neuromuscular disorders (incl. polio) 350-359, 045-049,138
    Ophthalmic disorders (excl. conjuctivitis) 360-71, 374-9,V41
    Dental diseases 520-522, 524-526
    Otic disorders (excl. otitis media) 383-387, 389
    Renal failure * 582-589
    Spina bifida * 741
    Thyroid disease * 240-246
    Miscellaneous V12, V13, V15, V42, V43, V45-V47

    Note: * - conditions which require chronic use of medications/devices

    B. Conditions Likely to Recur: ICD-9-CM Diagnosis Code

    Anemia 280
    Benign tumour 216
    Conjuctivitis/blepharitis 372-373
    COPD (eg. bronchitis) 490-2,494-6
    Gastroenteritis (noninfectious diarrhea) 558
    Gastrointestinal ulcer and diseases 530-537
    Gastrointestinal disease, other (eg.constipation)560-569
    Hepatic/pancreatic disease 570-577
    Hernia 550-553
    Joint pain 719, 724, 729
    Migraines and headaches 346,784
    Nephritis/nephrosis 580, 581
    Neurotic disorders (eg. enuresis, ADD) 300-316, V11,V40
    Otitis media 380-382
    Pregnancy diseases (incl. birth) 630-676, V22-V24, V27, V28
    Psychotic disorders (autism) 290-299
    Renal disease (eg. pyelonephritis, UTI) 590-599
    Reproductive organ disorders 600-629
    Respiratory disease, chronic (allergies) 470-478
    Respiratory disease, other 500-519
    Skin diseases (psoriasis) 690-698
    Social problems V60-V62
    Tuberculosis 010-018, 137
    Under-nutrition/Obesity 783, 278, 260-269

    C. Acute Self-limiting Conditions

    Appendicitis 540-543
    Ear symptoms 388
    Electrolyte disorders 274-276, 251
    Helminthiases 120-129
    Hemorrhage (incl. GI, other) 578, 459
    Hemorrhoids 455
    Ill-defined symptoms (excl. 783) 780-799
    Infectious/Parasitic diseases 001-9, 020-041, 080-088, 100-104, 130-6
    Injuries 800-999
    Meningitis 320-323
    Mouth disorders 523, 527-529
    Mycoses 110-118
    Pneumonia and influenza 480-487
    Procedures V50-V59, V63, V64, V66-V68
    Respiratory infections 460-466
    Rheumatic fever, acute 390-391
    Skin diseases, other (eg. rashes) 700-709
    Skin infections 680-686
    Venereal diseases 090-099
    Viral diseases (eg. chickenpox, mumps) 050-7, 060-066, 070-079, 139

    D. Perinatal Conditions (incl. birth)

    760-779, V29-V39

    E. Preventative Care

    Immunizations V01-V07
    Preventative, other V25, V26, V65, V69, V71-V82
    Routine Examinations V20, V21, V70
    Optometrist Examinations mdbloc=053

3 - SAS Program Code

    The program code categorizes ICD-9 diagnoses into: 1) acute conditions,2) recurrent conditions, 3) permanent conditions, 4) perinatal conditions and 5) visits for preventative care, as outlined in Table 1.

    • Note : Visits to the optometrist (mdbloc=053) were classified as visits for preventative care in another program.

    The operational definition of a recurrent condition was applied to the Table 1 list of ICD-9 diagnoses, as detailed in the program code (YYY). The basis steps in the program are as follows:

    1. division of fiscal year into quarter time periods and classification of a health care contact by its occurrence in a quarter time period (i.e.: 1,2,3,4).

    2. children with any occurrence of a hospitalization of > 7 days are classified with recurrent illness.

    3. of children with physician visits and short hospital stays (< 7days), those with at least 3 visits over 3 months (1 quarter) are defined as those with recurrent illness.

    4. for children excluded in ii) and iii), the presence of recurrent disease is determined if the sum of the label for the quarter time period for health care contact follows the patterns described in Table 2.

      Table 2. Operational Definition of a Recurrent Condition in a Child
      1st quarter = Apr,May,Jun;
      2nd quarter = Jul,Aug,Sep;
      3rd quarter = Oct,Nov,Dec;
      4th quarter = Jan,Feb,Mar.

      Quarter Time Periods Sum of Quarters* Pattern of Recurrence
      Recurrence in children with visits in 4th quarter if:
      4,3,2,1 10 4/4
      4,3,2 9 ¾ consecutive
      4,3,1 8 ¾ non-consecutive
      4,2,1 7 ¾ non-consecutive
      4,3 7 2/4 consecutive

      Non recurrent if:
      4,2 6 2/4 non-consecutive
      4,1 5 2/4 non-consecutive

      Recurrence in children with visits in 2nd and 3rd quarters if:
      3,2,1 6 3/3
      3,2 5 2/3 consecutive
      2,1 3 2/3 consecutive

      Non recurrent if:
      3,1 4 2/3 non-consecutive
      Note; * - quarter periods were summed to identify different patterns of recurrence; children were grouped by visits in the 2nd/3rd versus 4th quarter in order to differentiate sums of quarters which were the same but indicated different patterns of recurrence.

Related concepts 

Related terms 


  • Kozyrskyj A, Mustard CA, Derksen S. Considering the Health Care Needs of Children Living in Households Receiving Income Assistance in Manitoba: Family Services and Manitoba Health Pilot Project. Winnipeg, MB: Manitoba Centre for Health Policy and Evaluation, 2000. [Report] [Summary] (View)
  • Newacheck PW, Starfield B. Morbidity and use of ambulatory care services among poor and nonpoor children. American Journal of Public Health 1988;78(8):927-933. [Abstract] (View)
  • Perrin ED, Newacheck P, Pless B, Drotar D, Gortmaker SL, Leventhal J, Perrin JM, Stein RE, Walker DK, Weitzman M. Issues involved in the definition and classification of chronic health conditions. Pediatrics 1993;91(4):787-793. [Abstract] (View)
  • Starfield B, Katz H, Gabriel A, Livingston G, Benson P, Hankin, Horn S, Steinwachs D. Morbidity in childhood--a longitudinal view. New England Journal of Medicine 1984;310(13):824-829. [Abstract] (View)
  • Starfield B, Hankin J, Steinwachs D, Horn S, Benson P, Katz H, Gabriel A. Utilization and morbidity: random or tandem? Pediatrics 1985;75(2):241-247. [Abstract] (View)
  • Stein REK, Bauman LJ, Westbrook LE, Coupey SM, Ireys HT. Framework for identifying children who have chronic conditions: The case for a new definition. The Journal of Pediatrics 1993;122(3):342-347. [Abstract] (View)

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Manitoba Centre for Health Policy
Community Health Sciences, Max Rady College of Medicine,
Rady Faculty of Health Sciences,
Room 408-727 McDermot Ave.
University of Manitoba
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