Nongastrointestinal comorbidity may be a larger independent risk factor for gastrointestinal bleeding than previously thought, and may contribute more to bleeding than other recognized risk factors, a study found.
Upper gastrointestinal bleeding rates continue despite decreasing incidence of peptic ulcers, news treatments for Helicobacter pylori infection, and prophylaxis against ulceration from nonsteroidal anti-inflammatory drugs.
To investigate whether comorbidity itself increased the risk of gastrointestinal bleeding, researchers conducted a matched case-control study using primary care and secondary care data collected in England from April 1997 through August 2010. More than 16,000 patients with nonvariceal gastrointestinal bleeding were matched to five controls (nearly 82,000 patients).
Results appeared in the June issue of Gastroenterology.
Comorbidity had a strong graded association with gastrointestinal bleeding, the authors wrote. The adjusted odds ratio for a single comorbidity was 1.43 (95% confidence interval [CI], 1.35 to 1.52) and for multiple or severe comorbidity was 2.26 (95% CI, 2.14% to 2.38%).
The additional population attributable fraction for comorbidity (19.8%) was considerably larger than that for any other measured risk factor, including use of aspirin (3.0%) or NSAIDs (3.1%).
The largest association with a bleed was among patients with a previous Mallory-Weiss syndrome, which reflects the inherent risk of bleeding in recurrent vomiters. The highest variance inflation factors were for angiodysplasia (1.48) and dialysis (2.35).
Researchers wrote that this study contradicts current beliefs that the bleeding stems from known iatrogenic causes, such as NSAIDs prescribed for analgesia or antiplatelet agents prescribed for cardiac and cerebrovascular disease, and that this would be reduced by increasing use of proton pump inhibitors.
They wrote, "Instead, we have demonstrated that the extra contribution of these medications to bleeding cases was not large after considering the contributions of other risk factors present in the population. Therefore, simply increasing PPI prescriptions in patients on high-risk medications might not have as large an impact as previously thought."