Inappropriate testing for diarrheal diseases in the hospital

Although bacterial stool pathogens and parasitic organisms such as Salmonella, Shigella, or Campylobacter do not usually cause hospital-acquired diarrhea, it remains common practice in many institutions to order routine stool cultures and ova and parasite (O & P) examinations on all patients with symptoms. The degree to which these tests are inappropriately ordered was studied by examining the relation between test results from stool cultures, O & P examinations, and Clostridium difficile toxin assays and the time at which these tests were ordered after hospital admission. During a three-year period, only one of 191 positive stool cultures and none of the positive O & P examinations were obtained from patients whose stool specimens were obtained at least three days after admission. As expected, most positive results were not related to hospital-acquired diarrhea. However, analysis of laboratory workload for a one-year period showed that half of more than 3,000 stool specimens received each year are from patients hospitalized for three days or more. Twenty-five percent of the stool samples were positive for C. difficile, regardless of the patients' admission status, indicating that testing for C. difficile toxin is warranted. The results demonstrate that eliminating routine stool culture and O & P examinations on hospitalized patients would reduce hospital and patient costs without affecting patient care and possibly would result in a nationwide cost savings of $20 to $30 million per year. (Consumer Summary produced by Reliance Medical Information, Inc.)