Introduction

Microscopic colitis (MC) is an inflammatory gastrointestinal disease which typically presents with chronic watery diarrhea without blood. Despite a rising incidence over the last decades (1), studies on health economic outcomes are lacking.

Aims & Methods

In this cost-of-illness study, we estimate the societal economic burden of MC encompassing costs for healthcare, medications, and work loss, by the use of real-world data from Swedish health registers.
Through biopsy reports from Sweden’s 28 pathology departments, we identified 11,530 adult patients with MC as of January 1, 2017. Each patient was compared to up to 5 general-population comparators matched on date of birth, sex, and county of residence. Healthcare costs were based on prescription medications as well as non-primary outpatient visits and hospitalizations that included endoscopic procedures, while productivity losses were derived from work loss due to sick leave or disability leave. Mean differences were adjusted for age, sex, and education level. All costs were adjusted for inflation and converted from Swedish currency, SEK, to USD according to the annual average conversion rate in 2016 (1 USD = 8.5613 SEK or 0.9040 EUR).

Results

In 2016, patients with MC had a mean annual cost of $11,782 as compared with $6,170 in general-population comparators, corresponding to an annual excess cost of $5,615 per patient (adjusted mean difference $5,628 [95%CI: $5,278-$5,978], Table 1).
Even though less than half of the patients with MC were of working age (18-64 years, 42.5%), work loss was the largest cost component and accounted for more than half of the mean annual excess cost (57.7%). Excess costs related to hospitalizations accounted for 18.1%, whereas costs related to outpatient visits and medications accounted for 12.6% and 13.4% respectively. Although patients with MC had an increased use of MC-related medications such as local acting steroids (ATC code A07EA), these costs were comparatively small (mean annual cost, $106). Furthermore, MC-related healthcare costs such as colonoscopies, or outpatient visits and hospitalizations related to MC as defined by ICD code K.528, were negligible (mean annual cost, $68, $72 and $15 respectively).
The total annual societal cost of MC in Sweden was $135.9 million in 2016. By subtracting the baseline cost observed in general-population comparators, $64.7 million was found to be attributable to MC and MC-comorbidity.

Table 1. Use and cost of healthcare, prescription medications, and work loss in prevalent patients with microscopic colitis (MC) and general-population comparators in Sweden, 2016.

Conclusion

Patients with MC had an increased mean annual societal cost which was primarily driven by work loss. Healthcare costs specifically related to MC did not seem to be a major contributor to excess costs. Instead, excess healthcare costs in patients with MC are likely to be driven by concomitant disease. The societal economic burden of MC in Sweden was $135.9 million in 2016 with a population of 10.0 million and a prevalence of around 0.1%.

References

1. Bergman D, Clements MS, Khalili H, Agréus L, Hultcrantz R, Ludvigsson JF. A nationwide cohort study of the incidence of microscopic colitis in Sweden. Aliment Pharmacol Ther. 2019 Jun;49(11):1395-1400.

Disclosure

Dr Ludvigsson coordinates a study on behalf of the Swedish IBD quality register (SWIBREG). That study has received funding from the Janssen corporation. Dr Ludvigsson has also received financial support from MSD to develop a paper reviewing national healthcare registers in China.

Introduction

The Ki-67 labeling index is a well-established marker of cellular proliferation and has been associated with worse disease-free and overall survival in gastrointestinal stromal tumors (GISTs). Recent evidence highlights its potential role in risk stratification, particularly when Ki-67 exceeds certain thresholds. However, current assessment relies on postoperative histopathology. Radiomics, by extracting quantitative features from computer tomography (CT) images, may offer a non-invasive method to predict Ki-67 expression preoperatively. This meta-analysis aimed to evaluate the diagnostic performance of CT-based radiomics for predicting Ki-67 status in GISTs.

Aims & Methods

A systematic review and meta-analysis were conducted according to PRISMA guidelines). Four electronic databases (PubMed, Scopus, Science Direct, Cochrane Library) were searched for relevant articles up to December 2024. Eligible studies assessed CT radiomics in predicting Ki-67 in histologically confirmed GISTs. Pooled sensitivity, specificity, and area under the curve (AUC) were calculated using a random-effects model. Subgroup analyses were performed based on cohort type, CT protocol, number of features, and Ki-67 cutoff values. Study quality was assessed using the QUADAS-2 tool.

Results

Six studies comprising 1,632 patients met the inclusion criteria. Pooled sensitivity and specificity were 0.71 (95% CI: 0.63–0.79) and 0.76 (95% CI: 0.73–0.78), respectively. The pooled AUC was 0.79 (95% CI: 0.74–0.84). Subgroup analyses showed consistent performance across imaging protocols and feature counts, while Ki-67 cutoffs (8% vs. 10%) significantly impacted diagnostic accuracy. Sensitivity analysis confirmed robustness of specificity estimates. Publication bias was detected for specificity (Egger’s test p = 0.006).

Conclusion

CT radiomics demonstrates moderate accuracy for non-invasively predicting Ki-67 expression in GISTs. Given Ki-67's prognostic significance, radiomics could support preoperative risk assessment and personalized treatment planning. Further prospective validation is warranted.

Disclosure

No Conflict of Interest ​