Inadequate barium enemas in hospitalized elderly patients. Incidence and risk factors.

The likelihood of obtaining interpretable results is as important as sensitivity and specificity in selecting diagnostic tests. We reviewed medical and radiologic records of 140 consecutive inpatients over the age of 65 years who underwent a nonemergent barium enema. In 43 (31%) of these patients, the examination was incomplete or the results were uninterpretable. Thirteen patients could not retain the barium, and 27 patients had too much stool. Characteristics associated with an inadequate barium enema included confusion (adjusted odds ratio, 3.5), fever (adjusted odds ratio, 4.1), and cachexia (adjusted odds ratio, 2.7). Characteristics more common among subjects unable to retain barium than among subjects with too much stool were diarrhea (38% vs 18%) and fecal incontinence (31% vs 0%). The high frequency of inadequate results suggests that clinicians should consider whether a barium enema is the appropriate test in elderly patients with these characteristics, and, if so, what interventions may increase the chance for success.