Spotlight on the cost of gastroenteritis

Two industry-funded studies looked at the economic burden of acute infectious gastroenteritis among U.S. adults and found that use of large multiplex polymerase chain reaction panels was associated with similar costs as traditional workup.

Two recently published studies assessed the costs associated with acute infectious gastroenteritis in U.S. adults. Both were funded by diagnostic-test maker bioMérieux Inc., and several study authors were either employees of or paid consultants to the company.

The first, a retrospective cohort study, found that acute infectious gastroenteritis is a common and costly medical condition that predominately affects women. Researchers used the PINC AI Healthcare Database to identify adult patients with the diagnosis (captured by ICD-10-CM codes) between Jan. 1, 2016, and June 30, 2021, and performed pathogen detection analysis in those with microbiology data available. The main outcomes were health care resource use and health care cost, including the costs of the total index visit, stool testing, postdischarge services, and ancillary diagnostic tests within 30 days of the index visit. Results were published Feb. 3 by the American Journal of Gastroenterology.

Among 248,896 patients, the mean age was 44.3 years (range, 18 to 89 years), 62.9% were female, and 68.5% were White. Sixty-two percent had no pre-existing comorbidities, and 18.3% underwent stool testing at the hospital. Among 3,225 patients with diagnosis codes for inflammatory bowel disease (IBD), 38.2% underwent a stool test during the index visit. Most patients (84.7%) were seen in the ED, with 96.4% discharged home. Within 30 days of discharge, 1.0% were hospitalized and 2.8% had another outpatient visit due to acute infectious gastroenteritis. The mean cost of the index visit plus 30-day gastroenteritis-related follow-up was $1,338 per patient, amounting to $333,060,182 for the total study population. Among 12,469 patients with microbiology data available, common pathogens detected were Clostridioides difficile (32.2%), norovirus (6.3%), and Campylobacter spp. (4.0%). Patients with IBD who underwent stool testing were more likely to have a pathogen detected and were more likely to harbor C. difficile compared with those without IBD. Among other limitations, the study was a secondary data analysis using a hospital administrative database, the authors noted. “These results will be useful for clinicians and administrators responsible for the allocation of health care resources for adult outpatients with [acute infectious gastroenteritis],” they wrote, noting that one of the most striking findings was the female predominance of the condition (1.7:1 ratio).

The second study found that large multiplex polymerase chain reaction (PCR) panels were associated with costs comparable to traditional stool workup, defined as any charges related to stool culture, single-pathogen PCR test, immunology test, microscopy, and ova and parasites test during the index visit. Researchers looked at U.S. adult patients with a principal discharge diagnosis of acute infectious gastroenteritis and stool testing performed during an outpatient visit at one of the hospitals submitting data to the PINC AI Healthcare Database between April 1, 2016, and June 30, 2021. The main outcomes were health care resource use and health care cost. Results were published Jan. 16 by the Journal of Clinical Microbiology.

Among 36,787 patients, traditional workup was performed in most (57.0%). Multiplex PCR panel with 12 or more target pathogens (PCR12) was more common than traditional workup at large, urban, and teaching hospitals (P<0.01 for all). PCR12 was associated with a higher mean index visit cost (by $97) but a lower mean 30-day diagnosis-related follow-up cost (by $117) than traditional workup. In addition, patients with PCR12 had a lower 30-day gastroenteritis-related hospitalization risk than those receiving traditional workup (1.7% vs. 2.7%; P<0.01). Among 8,451 patients with microbiology data, PCR12 was associated with fewer stool tests per patient (mean, 1.61 vs. 1.26), faster turnaround time (mean, 6.3 h vs. 25.7 h), and lower likelihood of receiving in-hospital antibiotics (39.4% vs. 47.1%; P<0.01 for all) than traditional workup. A higher percentage of patients with PCR12 had a target pathogen detected (73.1%) compared to those who received multiplex PCR panel with less than 12 target pathogens (63.6%) or traditional workup (45.4%; P<0.01). The study was subject to potential coding errors affecting the accuracy of patient identification, among other limitations, the authors noted. “Higher material costs were offset by lower costs of follow-up care, so that overall health care costs for the index visit plus 30-day follow-up were comparable for PCR panels and traditional work-up,” they concluded.