Can patient characteristics predict the outcome of endoscopic evaluation of iron deficiency anemia: a multiple logistic regression analysis.
BACKGROUND
The purpose of this study was to identify clinical and biochemical variables that predict the outcome of upper/lower endoscopy in outpatients with iron deficiency anemia and to determine which endoscopic procedure should be performed first.


METHODS
Ninety-eight patients (74 women, 24 men; mean age 55 years) with iron deficiency anemia referred from the hematology department were interviewed and responded to a questionnaire that included clinical and biochemical variables, and underwent EGD (with biopsies) and colonoscopy. The endoscopic findings were recorded as presence/absence of GI cancer, upper/lower GI tract lesions and bleeding/non-bleeding-associated GI lesions. A multiple logistic regression analysis was applied to identify variables significantly related with the outcome of the investigations. Multiple analyses were performed so that a Bonferroni correction for multiple testing removed significance except where p<0.01.


RESULTS
A likely cause of iron deficiency anemia was found in 86.7% of patients. The risk factors for GI malignancies were: male gender (OR 7.5: 95% CI[1.7, 31.9]; p<0.01), advanced age (OR 1.1/y: 95% CI[1, 1.2]; p<0.01), and lower mean corpuscular volume (OR 1.1/unit: 95% CI[1, 1.2]; p<0.002). The risk factors for bleeding-related diseases were the following: greater age (OR 1.1/y: 95% CI[1.1, 1.2]; p<0.001), absence of lower-GI tract symptoms (OR 4.7: 95% CI[1.3, 16.6]; p<0.05), and a positive fecal occult blood test (OR 4.1: 95% CI[1.2, 14.3]; p<0.05). The risk factors for non-bleeding-related GI tract diseases were the following: negative fecal occult blood test (OR 4.5: 95% CI[1.16, 20]; p<0.05) and higher Hb level (OR 1.4/unit: 95% CI[1.1, 1.8]; p<0.05).


CONCLUSIONS
For non-hospitalized patients with iron deficiency anemia, colonoscopy should be the initial investigation in those greater than 50 years of age, particularly men, and those without upper-GI tract symptoms and with lower values for mean corpuscular volume and Hb. EGD should be performed first in younger patients, particularly those with a mild decrease in Hb and a negative fecal occult blood test.
Capurso
Gabriele
G
Digestive and Liver Disease Unit, 2nd School of Medicine, Department of Public Health Science University La Sapienza, Rome, Italy.
Baccini
Flavia
F
Osborn
John
J
Panzuto
Francesco
F
Di Giulio
Emilio
E
Delle Fave
Gianfranco
G
Annibale
Bruno
B
D000367:Age Factors; D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000209:etiology*; D001706:Biopsy; D003113:Colonoscopy; D004386:Duodenum / Q000473:pathology; D016099:Endoscopy, Gastrointestinal; D004909:Erythrocyte Indices; D005260:Female; D005767:Gastrointestinal Diseases / Q000150:complications / Q000175:diagnosis; D006471:Gastrointestinal Hemorrhage / Q000175:diagnosis* / Q000209:etiology; D005770:Gastrointestinal Neoplasms / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009780:Occult Blood; D016017:Odds Ratio; D012044:Regression Analysis; D012307:Risk Factors; D013270:Stomach / Q000473:pathology