SAN DIEGO – Since the late 1990s, when the annual number of antireflux procedures performed in the United States peaked, the overall rate of complications has increased, operations have shifted to more complex procedures in sicker patients, and the largest gains in caseload have occurred at urban nonteaching hospitals.

Those are three key findings from a large analysis of National Inpatient Sample (NIS) data reported by Dr. Paul D. Colavita at the annual Digestive Disease Week.

"Around the same time that antireflux surgery surged in the late 1990s, the Leapfrog Group – a large consortium of public and private health care purchasers – emerged as leaders in the national call for regionalization of complex surgical procedures in 2000," said Dr. Colavita, of the general surgery department at Carolinas Medical Center, Charlotte, N.C. "The objective of our study was to measure the extent of regionalization from its peak in 1998-1999 with data from 2008-2009."

He and his associates examined NIS data from 1998-1999 and 2008-2009 for antireflux procedures performed on patients with a diagnosis of gastroesophageal reflux, esophagitis, esophageal ulcer, and hiatal hernia. They excluded cases of achalasia, gangrenous/incarcerated diaphragmatic hernia, and patients younger than 18 years.

To measure the effect of regionalization, the researchers used 1998-1999 annual hospital volume of antireflux operations stratified into one of three baseline terciles: low-volume centers, defined as 1-14 annual procedures; medium-volume centers (15-37 annual procedures); and high-volume centers (38 or more annual procedures). The researchers also compared complications and outcomes that occurred in 1998-99 (time period 1) with those that occurred in 2008-09 (time period 2).

Dr. Colavita reported that 11,803 procedures were performed in time period 1, compared with 8,855 in time period 2. The proportion of procedures performed at low-volume centers increased between time periods 1 and 2 (from 33.3% to 40.4%) and declined at high-volume centers (from 33.4% to 25.3%).

As has been found with other surgical procedures, outcomes improved in high-volume centers, he said. The researchers attribute the lack of regionalization, in part, to the increased number of surgeons trained to perform these procedures. "In the past decade, surgical residents have been trained to perform antireflux procedures," Dr. Colavita said. "These former residents are now general surgeons who are performing these procedures in a variety of hospitals in different locations, both urban and rural."

Certain baseline characteristics differed significantly between time periods 1 and 2, including age (a mean of 50 vs. 57 years, respectively), percentage of women (57% vs. 69%), percentage of white patients (91% vs. 85%), and those with a Charlson comorbidity index score of more than 1 (5% vs. 10%). All differences had a P value of less than .0001.

There was no difference in inpatient mortality between time periods 1 and 2 (0.41% vs. 0.34%, respectively; P = .433), but there were significant increases in the rate of complications (4% vs. 6%) and total charges ($16,000 vs. $40,000), while the frequency of routine discharge decreased (95% vs. 92%). All differences had a P value of less than .0001. The average length of stay increased by 0.15 days (P = .001).

Multivariate regression analysis revealed that between time periods 1 and 2, low-volume centers remained independently associated with increased complications (odds ratio 1.8 vs. 1.9, respectively), nonroutine discharge (OR 2.0 vs. 1.8), length of stay (0.82 vs. 0.94 days), and higher total charges ($2,700 vs. $3,200).

"Taking these findings into consideration, we as health care providers must decide whether or not to call for increased referrals to high-volume centers," Dr. Colavita said.

Multivariate regression revealed two significant predictors of antireflux procedures performed at low-volume centers during time periods 1 and 2: emergent admission (OR 3.7 vs. 3.0, respectively) and lack of private insurance (OR 1.3 in both). Nonwhite race was a significant predictor in time period 1 only (OR 1.8), while significant predictors in time period 2 only included residing in the poorest vs. wealthiest zip code (OR 1.2), decreasing age (OR 1.1), and female gender (OR 1.2).

Dr. Colavita also reported that rural hospitals had decreased surgical volume between time periods 1 and 2 (19% to 10%), while the volume increased at urban nonteaching hospitals (from 33% to 39%) and at urban teaching hospitals (from 48% to 51%).

"Urban teaching hospitals had the highest proportion of high-volume cases in both eras, while urban nonteaching hospitals had the highest proportion of low-volume cases in both eras," he said.

Dr. Colavita acknowledged certain limitations of the study, including the lack of opportunity for follow-up in the NIS database and the fact that there are no codes for redo fundoplications. Also, "higher volumes have a shorter length of stay," he said. "This is a smaller window to detect death, complications, and overall cost. We also lack operative details such as operative time."

Dr. Colavita said he had no relevant financial conflicts to disclose.

Antireflux Procedures Increasingly Performed at Low-Volume Centers