The Prevalence, Humanistic Burden, and Health Care Impact of Irritable Bowel Syndrome Among United States Veterans

Healthcare Costs of Irritable Bowel Syndrome and Irritable Bowel Syndrome Subtypes in the United States

INTRODUCTION

Contemporaneous data on healthcare costs of irritable bowel syndrome (IBS) in the United States are lacking. We aimed to estimate all-cause and IBS-specific costs in patients with and without IBS and to compare costs across IBS subtypes.

METHODS

Using Optum's deidentified Clinformatics Data Mart Database, we performed a retrospective cohort analysis of patients with and without IBS using data spanning 2016-2021. Patients with IBS were identified by ICD-10 codes. Controls were randomly selected from Clinformatics Data Mart Database participants. Primary outcomes were total all-cause and IBS-specific healthcare costs. Secondary outcomes were costs of individual services associated with any claim. Costs were compared between IBS and control groups and across IBS subtypes using propensity score weighting. Comorbidities were measured with the Elixhauser Comorbidity Index.

RESULTS

Comparison of 102,887 patients with IBS (77.9% female; mean ± SD age 60.3 ± 18.4 years; 75.8% white) and 102,887 controls demonstrated higher median (interquartile range) total costs per year ( P < 0.001) for patients with IBS ($13,288 [5,307-37,071]) than controls ($5,999 [1,800-19,426]). IBS was associated with increased healthcare utilization and higher median annual costs per patient for all services. Median (interquartile range) annual IBS-specific spending was $1,127 (370-5,544) per patient. Propensity score-weighted analysis across IBS subtypes revealed differences in total all-cause and IBS-specific costs and in costs of individual services. Highest spending was observed in IBS with constipation (all-cause $16,005 [6,384-43,972]; IBS-specific $2,222 [511-7,887]).

DISCUSSION

Individuals with IBS exhibit higher healthcare utilization and incur substantially higher all-cause costs than those without. Care costs differ by IBS subtype.

Irritable Bowel Syndrome in Veterans with Gulf War Illness Evaluated at VA's War-Related Illness and Injury Study Center

INTRODUCTION

Excess rates of Gulf War illness (GWI) and irritable bowel syndrome (IBS), two chronic multisymptom illnesses, have long been documented among nearly 700,000 veterans who served in the 1990-1991 Persian Gulf War. We sought to report the prevalence, characteristics, and association of GWI and IBS decades after the war in a clinical cohort of deployed Gulf War veterans (GWVs) who were evaluated at the Department of Veterans Affairs' War Related Illness and Injury Study Center (WRIISC) for unexplained chronic symptoms.

MATERIALS AND METHODS

We analyzed data gathered from clinical intake questionnaires of deployed GWVs who were evaluated at WRIISC clinics between 2008 and 2020. We applied Centers for Disease Control (CDC) criteria to determine the prevalence of severe GWI. IBS was identified using Rome IV diagnostic criteria (current IBS) and veterans' self-reported "history of physician-diagnosed IBS." We examined associations between IBS and GWI using bivariate analyses and multivariable logistic regression.

RESULTS

Among the N = 578 GWVs evaluated by the WRIISC, severe GWI (71.8%), history of physician-diagnosed IBS (50.3%) and current IBS (42.2%) were all highly prevalent. Nearly half of GWVs with severe GWI met Rome criteria for IBS (45.8%), and over half reported a history of physician-diagnosed IBS (56.1%). In multivariable models, severe GWI was significantly associated both with current IBS (adjusted odds ratio (aOR): 1.68, 95% CI: 1.11, 2.54) and with veteran-reported history of physician-diagnosed IBS (aOR: 2.15, 95% CI: 1.43, 2.23). IBS with diarrhea (IBS-D) was the most common subtype among GWVs with current IBS (61.1%). However, IBS-mixed affected a significantly greater proportion of veterans with severe GWI, compared to veterans who did not have severe GWI (P = .03).

CONCLUSIONS

More than 20 years after the Persian Gulf War, our findings indicate a high degree of comorbidity between severe GWI and IBS among deployed GWVs seeking care for unexplained illnesses. Our results suggest GWVs with GWI should be screened for IBS for which evidence-based treatments are available and could potentially reduce symptom burden. Conversely, symptoms of IBS should trigger additional evaluation for non-gastrointestinal symptoms in deployed Gulf War veterans to identify possible GWI and ensure a comprehensive approach to care.

Impact of Rome IV criteria on the prevalence of post-infection irritable bowel syndrome

BACKGROUND

The Rome IV irritable bowel syndrome (IBS) criteria include changes to the description and frequency of abdominal pain. Existing studies have demonstrated a lower prevalence and greater severity in IBS patients identified using Rome IV than Rome III criteria. Our aim was to investigate the prevalence of post-infection IBS (PI-IBS) using Rome IV criteria in a population-based cohort of laboratory-confirmed C. jejuni infection cases.

METHODS

The Minnesota Department of Health (MDH) requires notification of Campylobacter cases and interviews patients to gather information on clinical symptoms. For this study, the Rome IV diagnostic questionnaire was utilized 6-9 months after infection to determine the development of PI-IBS. The survey responses were analyzed for the prevalence of IBS and symptom severity.

KEY RESULTS

Surveys were completed by 391 participants (31% response rate). Twenty-three patients had pre-existing IBS, and 18 did not complete enough questions to categorize their case status. Of the 350 remaining participants, 58 (17%) met Rome IV criteria. An additional 47 patients would have met the Rome III IBS criteria for pain frequency, driving the cumulative prevalence to 30%. The mean IBS Symptom Severity Score (IBS-SSS) in Rome IV patients was significantly higher than in Rome III (p < 0.05). With Rome IV, IBS-diarrhea was the most common subtype.

CONCLUSIONS & INFERENCES

Rome IV criteria resulted in a 19% lower prevalence of PI-IBS than earlier reported Rome III-based prevalence in a similar population. Rome IV defined PI-IBS patients have greater symptom severity but similar distribution of IBS subtypes.