Diagnosis - Preventable Hospitalizations MICA

Preventable hospitalizations, as defined by Billings, et al. (1993), are "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..."  Missouri displays data on Preventable Hospitalizations MICA using guidelines obtained from the principal author. (Note that preventable hospitalizations is sometimes referred to in the literature as ambulatory care sensitive conditions.)

Hospital Exclusions

The term hospitalizations refers to acute care hospital discharges of Missouri residents from non-federal and non-state short-term (average length of stay less than 30 days) general and specialty hospitals whose facilities are open to the general public. Excluded from the hospitalization data are discharges from long-term care facilities, as well as those from long-term care units within general hospitals (i.e., swing bed, skilled nursing, and intermediate care units). Also excluded are discharges from residential care facilities and residential care units within licensed hospital facilities.

Inpatient admissions

Preventable Hospitalization MICA data reflect all sources of inpatient admissions, including direct admissions, transfers from emergency departments or other within-hospital units, and transfers from external facilities (i.e., other hospitals or long-term care facilities). The source of these data is the Patient Abstract System (PAS) data file, which is compiled hospital discharge records that are filed with the Department by state law. The reporting requirements for the PAS have been in place in Missouri continuously since 1993. However, due to changes in coding and continuity, this MICA contains data from 2001 forward.

Missing information

In some instances, certain data values in the patient record are missing or miscoded. Discharges with missing or miscoded data values are included in the statewide totals, but may not be included within the displayed categories of certain variables (e.g., race, county of residence, sex, payer type). Thus, a total of all categories of a variable may not equal the statewide total for that variable. Patients with a missing state of residence were deleted from the analysis file. Those discharge records identified as Missouri residents, but missing a county identifier, are included in the statewide totals only.

Comparisons with Other MICAs

The data for the Preventable Hospitalizations MICA has a few selection criteria differences from those normally used in other PAS related MICAs. Newborns are a special category of hospital discharges that are not included in the other MICAs that contain PAS data nor for the PAS-hospitalization indicators found on the Community Data Profiles. In the Preventable Hospitalizations MICA, newborns are included, except where inappropriate (exceptions can be viewed here).

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 under Diagnosis on the query page. For data through September of 2015, all diagnoses and procedures were specified using the International Classification of Diseases, Ninth Revision (ICD-9-CM).


Billings J, Anderson GM, Newman LS: Recent findings on preventable hospitalizations, Health Affairs 1996; (Fall)15:239-249.

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.