Rates and characteristics of complicating conditions, 2008

Table 2 shows the rates of complicating conditions among maternal stays. During an individual stay, multiple complicating conditions may be recorded; some may be more recorded as the principal diagnosis and some may be recorded as the secondary diagnosis. This table provides a complete accounting of all complicating conditions regardless of their severity.

Table 2

Counts, rates, and mean maternal age for all-listed complicating conditions for maternal stays with and without delivery, 2008.

Non-delivery stays

As shown in table 2, among non-delivery maternal stays, the following complicating conditions occurred at a rate of 100 or more for every 1,000 hospital stays:

• early or threatened labor (208 per 1,000 stays)
• infections of genitourinary tract (132 per 1,000 stays)
• hypertension including eclampsia and pre-eclampsia (113 per 1,000 stays)

The following complicating conditions occurred at a rate of 50–99 for every 1,000 hospital stays:

• anemia (99 per 1,000 stays)
• diabetes or abnormal glucose tolerance (82 per 1,000 stays)
• hyperemesis gravidarum (vomiting) (63 per 1,000 stays)
• poor fetal growth (60 per 1,000 stays)
• ectopic pregnancy (56 per 1,000 stays)
• advanced maternal age (56 per 1,000 stays)
• hemorrhage (52 per 1,000 stays)

Delivery stays

Among maternal stays with delivery, the following common complicating conditions occurred at a rate of 100 or more for every 1,000 deliveries:

• umbilical cord complications (233 per 1,000 stays)
• perineal lacerations (158 1st degree and 168 2nd degree lacerations per 1,000 stays)
• previous cesarean section (167 per 1,000 stays)
• abnormality in fetal heart rate or rhythm (148 per 1,000 stays)
• prolonged pregnancy (121 per 1,000 stays)
• polyhydramnios and problems of the amniotic cavity (117 per 1,000 stays)
• advanced maternal age (117 per 1,000 stays)
• anemia during pregnancy (112 per 1,000 stays)
• fetal distress and abnormal forces of labor (111 per 1,000 stays)

The following complicating conditions occurred at a rate of 50–99 for every 1,000 deliveries:

• hypertension including eclampsia and pre-eclampsia (94 per 1,000 stays)
• early or threatened labor (81 per 1,000 stays)
• malposition, malpresentation (80 per 1,000 stays)
• diabetes or abnormal glucose tolerance (68 per 1,000 stays)
• poor fetal growth (54 per 1,000 stays)
• fetopelvic disproportion (54 per 1,000 stays)

Patient characteristics of maternal hospitalizations

The average age for patients with complicating conditions was about 2 years older (27.2 years for non-delivery stays and 27.7 years for complicated delivery stays) than for patients delivering without complicating conditions (25.5 years). Figure 1 shows that patients 35 to 44 years accounted for 15 percent of maternal stays with complicating conditions (with or without delivery), but comprised only 1 percent of delivery stays without complicating conditions.

Figure 1

Percentage distribution of pregnancy and childbirth stays with and without complicating conditions, by age group, U.S. hospitals, 2008. Source: AHRQ, Center for Delivery, Organization and Markets, Healthcare Cost and Utilization Project, Nationwide Inpatient (more...)

As shown in table 1, Medicaid and private insurance were the most common expected payers for all maternity stays. For non-delivery stays with complicating conditions, Medicaid was the most common expected payer (45.5 percent), closely followed by private insurance (42.9 percent). Private insurance was the most common expected payer for delivery stays with complicating conditions (53.2 percent), followed by Medicaid (39.7 percent). About half of all delivery stays without complicating conditions of pregnancy were billed to Medicaid (50.5 percent), while 41.8 percent were billed to private insurance.

Hospitalization rates for non-delivery stays with complicating conditions and delivery stays (with and without complicating conditions) were highest in the poorest communities and declined with increasing income (figure 2). Across all three types of maternal stays, the rate of stays was higher for women living in large urban areas and rural areas (micropolitan and noncore) and lower for women living in medium and small metropolitan areas (figure 3).

Figure 2

Rates of pregnancy and childbirth stays with and without complicating conditions, by community income, U.S. hospitals, 2008. Source: AHRQ, Center for Delivery, Organization and Markets, Healthcare Cost and Utilization Project, Nationwide Inpatient Sample (more...)

Figure 3

Rates of pregnancy and childbirth stays with and without complicating conditions, by patient residence, U.S. hospitals, 2008. Source: AHRQ, Center for Delivery, Organization and Markets, Healthcare Cost and Utilization Project, Nationwide Inpatient Sample (more...)

Figure 4 shows the rates of pregnancy and childbirth stays with and without complicating conditions by region. Regional differences were not statistically significant for stays with complications (with or without delivery). Delivery stays without complications were lowest in the Northeast and highest in the South and West.

Figure 4

Rates of pregnancy and childbirth stays with and without complicating conditions, by region, U.S. hospitals, 2008. Source: AHRQ, Center for Delivery, Organization and Markets, Healthcare Cost and Utilization Project, Nationwide Inpatient Sample (NIS), (more...)

Diagnoses, ICD-9-CM, and Clinical Classifications Software (CCS)

The principal diagnosis is that condition established after study to be chiefly responsible for the patient’s admission to the hospital. Secondary diagnoses are concomitant conditions that coexist at the time of admission or that develop during the stay.

ICD-9-CM is the International Classification of Diseases, Ninth Revision, Clinical Modification, which assigns numeric codes to diagnoses. There are about 13,600 ICD-9-CM diagnosis codes.

CCS categorizes ICD-9-CM diagnoses into a manageable number of clinically meaningful categories.⁴ This “clinical grouper” makes it easier to quickly understand patterns of diagnoses and procedures. For table 2, the Multi-Level CCS was used to examine more specific categories of conditions. The Multi-Level CCS is a hierarchical system that is defined using both single-level CCS groupings and ICD-9-CM codes.⁵

For this report, CCS codes 177–195 were used to identify complicating conditions of pregnancy and childbirth. Delivery stays were identified by ICD-9-CM diagnosis codes 640.0–676.9, where the fifth digit is 1 or 2, or ICD-9-CM 650. Maternal stays were identified as having an all-listed ICD-9-CM diagnosis code in the delivery range or an all-listed CCS code 177–195. All stays were limited to patients’ ages 15 to 44 years.

Types of hospitals included in HCUP

HCUP is based on data from community hospitals, defined as short-term, non-Federal, general and other hospitals, excluding hospital units of other institutions (e.g., prisons). HCUP data include OB-GYN, ENT, orthopedic, cancer, pediatric, public, and academic medical hospitals. Excluded are long-term care, rehabilitation, psychiatric, and alcoholism and chemical dependency hospitals. Please note, a discharge of this nature will be included in the NIS if it occurred in a community hospital.

Unit of analysis

The unit of analysis is the hospital discharge (i.e., the hospital stay), not a person or patient. This means that a person who is admitted to the hospital multiple times in one year will be counted each time as a separate “discharge” from the hospital.

Costs and charges

Total hospital charges were converted to costs using HCUP Cost-to-Charge Ratios based on hospital accounting reports from the Centers for Medicare and Medicaid Services (CMS).⁶ Costs will tend to reflect the actual costs of production, while charges represent what the hospital billed for the case. For each hospital, a hospital-wide cost-to-charge ratio is used because detailed charges are not available across all HCUP States. Hospital charges reflect the amount the hospital charged for the entire hospital stay and does not include professional (physician) fees. For the purposes of this Statistical Brief, costs are reported to the nearest hundred.

Urban-rural location

Urban-rural location is one of six categories as defined by the National Center for Health Statistics:

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Large Central Metropolitan: Central counties of metropolitan areas with a population of 1 million or greater

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Large Fringe Metropolitan: Fringe counties of counties of metropolitan areas with a population of 1 million or greater

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Medium Metropolitan: Counties in metro area of 250,000–999,999 population

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Small Metropolitan: Counties in metro areas of 50,000–249,999 population

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Micropolitan: Micropolitan counties, i.e. a non-metropolitan county with an area of 10,000 or more population

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Non-core: Non-metropolitan and non-micropolitan counties

In this report, medium and small metropolitan were combined into one category and micropolitan and non-core were combined and labeled “rural.”

Median community-level income

Median community-level income is the median household income of the patient’s ZIP Code of residence. The cut-offs for the quartile designation are determined using ZIP Code demographic data obtained from Claritas. The income quartile is missing for homeless and foreign patients.

Payer

Payer is the expected primary payer for the hospital stay. To make coding uniform across all HCUP data sources, payer combines detailed categories into more general groups:

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Medicare includes fee-for-service and managed care Medicare patients.

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Medicaid includes fee-for-service and managed care Medicaid patients. Patients covered by the State Children's Health Insurance Program (SCHIP) may be included here. Because most state data do not identify SCHIP patients specifically, it is not possible to present this information separately.

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Private insurance includes Blue Cross, commercial carriers, and private HMOs and PPOs.

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Other includes Workers’ Compensation, TRICARE/CHAMPUS, CHAMPVA, Title V, and other government programs.

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Uninsured includes an insurance status of “self-pay” and “no charge.”

When more than one payer is listed for a hospital discharge, the first-listed payer is used.

Region

Region is one of the four regions defined by the U.S. Census Bureau:

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Northeast: Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, and Pennsylvania

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Midwest: Ohio, Indiana, Illinois, Michigan, Wisconsin, Minnesota, Iowa, Missouri, North Dakota, South Dakota, Nebraska, and Kansas

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South: Delaware, Maryland, District of Columbia, Virginia, West Virginia, North Carolina, South Carolina, Georgia, Florida, Kentucky, Tennessee, Alabama, Mississippi, Arkansas, Louisiana, Oklahoma, and Texas

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West: Montana, Idaho, Wyoming, Colorado, New Mexico, Arizona, Utah, Nevada, Washington, Oregon, California, Alaska, and Hawaii

Discharge status

Discharge status indicates the disposition of the patient at discharge from the hospital, and includes the following six categories: routine (to home), transfer to another short-term hospital, other transfers (including skilled nursing facility, intermediate care, and another type of facility such as a nursing home), home health care, against medical advice (AMA), or died in the hospital.