Healthcare Information Division

AHRQ - Inpatient Quality Indicators (IQIs)

Hospital Volume and Utilization Indicators for California

The following is a brief description of 11 Hospital Inpatient Quality Indicators (Inpatient Quality Indicators, Version 4.5) including 6 new subcategories (2 for Pancreatic Resection Volume and 4 for AAA Repair Volume) developed by the federal Agency for Healthcare Research and Quality (AHRQ) and provided by OSHPD for use by California consumers and health care providers.

The methods for calculating these indicators, along with detailed technical explanations are provided by AHRQ at their website. AHRQ also provides valuable guidance regarding the validity of these indicators and important limitations on their use as quality measures. Details are available in documents found at their website: http:www.qualityindicators.ahrq.gov.

Visit the California Health and Human Services Open Data Portal:


Number of Selected Inpatient Medical Procedures
Utilization Rates for Selected Medical Procedures

To view hospital volume and utilization information click these links:

Note that all years of data on this page have been updated using Version 4.5 of the AHRQ software.

Volume Indicators

Volume means the number of medical procedures of a given type that are done within one year. Medical research has linked higher hospital volumes for some complex surgical procedures with better patient outcomes (such as fewer deaths). Some research, however, has not found evidence for a "practice makes perfect" association, and the evidence base for this association varies by procedure. Also, other factors such as individual physician or surgical team experience may play an equal or even more important role. OSHPD does not endorse the use of the volume indicators as stand-alone measures of hospital quality. However, in the absence of other valid quality information, these indicators may prove useful to the public in making more informed healthcare decisions.

Details: The six volume indicators simply provide the number of procedures performed within each hospital. They are:

  • Esophageal Resection
    Research shows a link between higher numbers of cases and better outcomes.
  • Pancreatic Resection
      • Pancreatic Resection, Cancer
      • Pancreatic Resection, Other
    • Research shows a link between higher numbers of cases and better outcomes.
  • Abdominal Aortic Aneurism Repairs (AAA Repair)
      • AAA Repair ruptured, Open
      • AAA Repair unruptured, Open
      • AAA Repair ruptured, Endovascular
      • AAA Repair unruptured, Endovascular
    Research shows a link between higher numbers of cases and better outcomes.
  • Carotid Endarterectomy
    Research shows a link between higher numbers of cases and better outcomes.
  • Coronary Artery Bypass Graft Surgery (CABG)
    Research findings are unclear about whether there is a link between higher numbers of cases and better outcomes.
  • Percutaneous Coronary Intervention (PCI)
    Most research shows a link between higher numbers of cases and better outcomes.

Utilization Indicators

Utilization refers to the percent of times that a medical treatment is done using a particular type of procedure. These indicators are for procedures where evidence shows there is under-use or over-use, along with large variation in rates across hospitals. That is, procedures for some patients may be over-used (e.g., Cesarean section for child birth) and others may not be used enough (e.g., vaginal birth after previously having a baby by Cesarean section), given current medical care standards. A hospital with very high or very low utilization rates relative to other hospitals may be a reason for concern, though certain hospital characteristics (e.g., being a referral center where other hospitals send complex cases) may help explain extreme rates. These utilization rates represent the number of patients who are treated using a specific type of procedure per 100 patients admitted for the more general category of treatment.

For example: Hospital A has a Cesarean section rate of 20.3% (277). This means that Hospital A performed 277 Cesarean sections and these represented 20.3% of all the births ( 1365- number not included in table) at Hospital A that year.

Rate Explanations:

  • Cesarean Delivery Rate
    Number of Cesarean Section Deliveries per 100 deliveries (excludes abnormal presentation, preterm birth, fetal death, multiple gestations, and breech procedure). Cesarean delivery may be overused in some facilities, so lower rates may represent better care.
  • Cesarean Delivery Rate - Primary
    Number of Cesarean Deliveries per 100 deliveries among women who have not previously had a Cesarean section (excludes abnormal presentation, preterm, fetal death, multiple gestation, and breech procedures). Cesarean delivery may be overused in some facilities, so lower rates may represent better care.
  • Vaginal Birth After Cesarean (VBAC) Rate
    Number of vaginal births per 100 women with a previous Cesarean delivery. VBAC may be underused in some facilities, so higher rates may represent better care, though this rate includes some women who were probably not good candidates for vaginal birth.
  • Vaginal Birth After Cesarean (VBAC) Rate, Uncomplicated
    Number of vaginal births per 100 women with a previous Cesarean delivery (excludes abnormal presentation, preterm birth, fetal death, multiple gestation, and breech procedures). VBAC may be underused in some facilities, so higher rates may represent better care.
  • Laparoscopic Cholecystectomy
    Number of Cholecystectomies (surgical removal of gall bladder) performed with use of Laparoscope per 100 cholecystectomies. Laparoscopic Cholecystectomy is a new technology with lower risks than open cholecystectomy. Higher rates may represent better care.
Page last revised: December 5, 2014 2:39 PM