Purpose: We examined the effect of introducing an evidence-based clinical guideline on the diagnosis and evaluation of iron deficiency anemia.
Subjects and methods: The guideline recommended measurement of serum ferritin levels for all anemic patients with a mean corpuscular volume (MCV) </=95 fL and endoscopic evaluation for those with a serum ferritin level less than 45 ng/mL. Physicians practicing in the general medicine inpatient and outpatient services of two university-affiliated hospitals were informed about the guideline and the data supporting it. Clinical evaluations during the 9 months before ("control period," n = 3341 patients) and the 9 months after ("intervention period," n = 3173 patients) the introduction of the guideline were compared.
Results: There was a 30% increase (95% confidence interval [CI]: 22% to 39%) in the proportion of anemic patients who underwent serum ferritin evaluation in the intervention period (41% [n = 1284]) compared with in the control period (31% [n = 1040]), and a 24% increase (95% CI: 4% to 48%) in the proportion with a serum ferritin level <45 ng/mL (8.1% [n = 256] vs. 6.5% [n = 217]). The proportion of anemic patients who underwent endoscopic evaluation within 4 months of measurement of low serum ferritin level in the intervention period (3.3% [n = 106]) was 67% higher (95% CI: 23% to 125%) than in the control period (2.0% [n = 67]), and the proportion with serious gastrointestinal lesions found as a result of endoscopy was 62% (95% CI: 8% to 145%) higher (1.8% [n = 57] vs. 1.1% [n = 37]).
Conclusions: Introduction of a guideline describing appropriate evaluation of iron deficiency anemia led to an increase in the proportions of patients evaluated for iron deficiency anemia and found to have serious gastrointestinal lesions.