Missouri displays data on Preventable Hospitalizations MICA using guidelines obtained from the principal author of the seminal 1993 study on preventable hospitalizations by Billings, et al (Billings J, Zeitel L, Lukomnik J, Carey TS, Blank AE, Newman L: Impact of socioeconomic status on hospital use in New York City. Health Affairs 1993; (Spring): 162-173.)The source of these data is the Patient Abstract System (PAS) data file, which is compiled from hospital discharge records that are filed with the Department of Health and Senior Services by state law.

For data prior to the fourth quarter of 2015, diagnoses and procedures associated with hospitalizations are classified in accordance with the Ninth Revision of the International Classification of Diseases (ICD-9). This classification is the result of close collaboration among many nations and non-governmental organizations, under the auspices of the World Health Organization. Its original use was to classify causes of mortality. Later, it was extended to include diagnoses in morbidity. For example, the "clinical modification" of the ICD is used in categorizing hospital diagnoses. In practice, the ICD has become the international standard diagnostic classification for all general epidemiological, as well as health management, purposes. The ninth revision of the ICD has been used to classify disease and procedures beginning January 1, 1979, through September 30, 2015.

One of the major differences in Preventable Hospitalization MICA compared to other PAS related MICAs is that some of the preventable conditions require the identification of procedures or secondary diagnoses, rather than relying exclusively on the principal diagnosis for each discharge. A list of the diagnoses and procedures used to define preventable hospitalizations can be found below.

Diagnoses and Procedures Definitions used for Preventable Hospitalizations

(An "x" with 3-digit codes indicates the selection of all 4- and 5-digit codes, also. All diagnoses and procedures specified at the International Classification of Diseases, Ninth Revision (ICD-9-CM) level.)

Preventable Diagnosis ICD-9 Codes
Angina Principal diagnosis of 4111, 4118, 413x AND
not with any procedure below 87000
Asthma Principal diagnosis of 493x
Bacterial Pneumonia Principal diagnosis of 481x, 4822, 4823, 4829, 483x, 485x, 486x AND
any secondary diagnosis that is not 2826 AND
age is 60 days and above
Cellulitis Principal diagnosis of 681x, 682x, 683x, or 686x AND
not with any procedure below 87000 except when the only procedure performed is one of 86000 through 86099
Chronic Obstructive Pulmonary (Disease) Principal diagnosis of 491x, 492x, 494x, 496x OR
a principal diagnosis of 4660 with a secondary diagnosis of 491x, 492x, 494x, 496x
Congenital Syphilis Principal Diagnosis is V3x (newborn) AND
any secondary diagnosis of 090x
Congestive Heart Failure Principal diagnosis of 428x, 40201, 40211, 40291, 5184 AND
not with any procedure code of 3601, 3602, 3605, 3610-36199, 375x, 3770-37799
Convulsions Principal diagnosis of 7803 AND
excludes newborns
Dehydration- Volume Depletion Principal diagnosis of 2765
Dental Conditions Principal diagnosis of 521x, 522x, 523x, 525x, 528x
Diabetes Principal diagnosis of 2500-2503, 2508-2509
Epilepsy Principal diagnosis of 345x
Failure to Thrive Principal diagnosis of 7834 AND
age is not 1 or above.
Gastroenteritis Principal diagnosis of 5589
Hypertension Principal diagnosis of 4010, 4019, 40200, 40210, 40290 AND not with any procedure code of 3601, 3602, 3605, 3610-36199, 375x, 3770-37799
Hypoglycemia Principal diagnosis of 2512
Immunization Preventable Principal diagnosis of 033x, 390x, 391x, 037x, 045x OR
a principal diagnosis of 3200 for ages greater than 0 but less than 6
Kidney/Urinary Infection Principal diagnosis of 590x, 5990, 5999
Nutritional Deficiencies (Includes Iron Deficiency Anemia) Principal diagnosis of 260x, 261x, 262x, 2680, 2681 OR
a principal diagnosis of 2801, 2808, 2809 for ages greater than 0 but less than 6
Pelvic Inflammatory Disease Principal diagnosis of 614x AND
sex is female AND
not with any procedure from 68300 through 68999
Severe ENT Infection Principal diagnosis of 382x, 462x, 463x, 465x, 4721 AND
not a procedure of 2001
Tuberculosis - Pulmonary Principal diagnosis of 011x 012x, 013x, 014x, 015x, 016x, 017x, 018x