Journal watch: Recent studies of note

Recent studies about C. difficile colitis, elderly patients and sleeping pills, and other topics.


C. difficile colitis now more common and more severe in hospitalized patients

Clostridium difficile colitis has increased in prevalence and severity in hospitalized patients in the U.S., according to a study.

Researchers used data from the Nationwide Inpatient Sample to determine the epidemiologic changes in C. difficile colitis in the U.S. between 1993 and 2003. Main outcome measures were disease prevalence, case fatality and total mortality rates, and rate of colectomy. The results appeared in the July Archives of Surgery.

From 1993 to 2003, 299,453 patients were discharged from the hospital with a primary or secondary diagnosis of C. difficile colitis. In this time frame, the prevalence of C. difficile colitis increased by 109% (from 261 cases per 100,000 discharged patients to 546 cases per 100,000 discharged patients). The case fatality rate increased from 7.84% in 1993 to 9.26% in 2003, and the total mortality rate increased by 147% (from 20.3 deaths per 100,000 discharges to 50.2 deaths per 100,000 discharges). Finally, the colectomy rate increased from 1.2 per 1,000 cases in 1993 to 3.4 per 1,000 cases in 2003. Increasing calendar year was associated with higher risk for the disease as well as increased severity.

The study results offer proof that C. difficile colitis in the U.S. is changing, the authors wrote, but do not explain the change. The authors speculated that new bacteria strains, increased antibiotic resistance or increasing illness severity and susceptibility to infection may be responsible, and called for further research on the topic.

Elderly patients often continue sleeping pills after hospitalization, study finds

Elderly patients who are first prescribed benzodiazepines during or soon after a hospital stay are often still taking them months later, a study found.

Researchers at the Institute for Clinical Evaluative Sciences in Toronto examined retrospective data on 405,128 patients age 66 years or older who were hospitalized between April 1, 1992, and March 31, 2005. The objective of the study was to determine how often elderly adults who are prescribed benzodiazepines in association with a hospital stay continue taking them after discharge. The results appeared in the July Journal of General Internal Medicine.

Overall, 12,484 patients (3.1%) who had not taken benzodiazepines in the year before hospitalization received prescriptions for the drugs within a week of hospital discharge. Of this group, almost 50% (6,136 patients, or 1.5% of the cohort) were categorized as “new chronic benzodiazepine users,” meaning they were still taking the drug within eight days to six months of hospitalization.

New long-term benzodiazepine use was most common in women, patients who stayed in the hospital longer, those with ICU or nonsurgical stays, those with greater overall comorbidity, those with a previous diagnosis of alcoholism and those with prescriptions for more medications.

In a press release, the study's lead author pointed out the associated risks of the drugs, such as residual daytime sedation, fall-related injuries and possible dependence.

“Initiatives such as the development of electronic medical records and more formal medication lists, or models of care that facilitate communication and coordination between hospital and community-based physicians, may help to further reduce the risk of new, chronic benzodiazepine prescriptions, particularly when targeted to the higher-risk patients identified in our study,” he said.

Study shows link between inhaled corticosteroids, pneumonia in COPD

Inhaled corticosteroids can lead to hospitalization for pneumonia in patients with chronic obstructive pulmonary disease (COPD), a study found.

Researchers at McGill University in Montreal analyzed prescription and hospitalization records between 1988 and 2003 for a cohort of 175,906 elderly COPD patients and for 95,768 matched controls to determine whether inhaled corticosteroids and pneumonia were related. The results appeared in the July 15 American Journal of Respiratory and Critical Care Medicine.

During follow-up (1,241,741 patient-years), approximately 14% of the cohort (23,942 patients) was hospitalized for pneumonia. The adjusted rate ratio was 1.70 (95% CI, 1.63 to 1.77) for pneumonia hospitalization associated with current inhaled corticosteroid use and 1.53 (CI, 1.30 to 1.80) for pneumonia hospitalization and death within 30 days. The highest doses of inhaled corticosteroids were associated with the greatest hospitalization risk (rate ratio, 2.25 [CI, 2.07 to 2.44]).

An accompanying editorial noted that these findings confirm those of an earlier randomized, placebo-controlled trial and recommended that additional large prospective studies should be performed. “The finding of an association between pneumonia frequency and inhaled corticosteroid use in studies of a different design, in different populations, and with evidence of a dose-response relationship means that the findings may be real and that these observations cannot simply be dismissed,” the editorialist wrote.

Pulmonary artery catheter use declines in U.S. hospitals, study shows

Use of pulmonary artery catheters in hospitalized patients decreased sharply in the U.S. between 1993 and 2004, a study found.

Researchers at Dartmouth Medical School used data from the Nationwide Inpatient Sample, part of the Agency for Healthcare Research and Quality's Cost and Utilization Project, to conduct a time trend analysis of pulmonary catheter use in hospitalized patients 18 years of age and older. The primary outcome measure was pulmonary artery catheterizations per 1,000 medical admissions per year. The results appeared in the July 26 Journal of the American Medical Association.

The authors found that use of pulmonary artery catheters decreased by 65% from 1993 to 2004, from 5.66 per 1,000 medical admissions to 1.99 per 1,000 medical admissions. The authors detected a change in trend following the 1996 publication of a study suggesting that pulmonary artery catheterization was associated with increased mortality. Among diagnoses that are often associated with pulmonary artery catheterization, rates of use declined most for myocardial infarction (81%) and least for septicemia (54%). The authors concluded that rates of pulmonary artery catheterization had decreased over time because physicians were appropriately responding to evidence that this invasive procedure doesn't reduce mortality in critically ill patients.

Experimental drug fails to help stroke patients

An experimental treatment for acute ischemic stroke, called NXY-059, is safe but ineffective, according to a large study. The findings contradict a previous trial which had found that NXY-059 improved outcomes significantly more than placebo.

Researchers had undertaken the randomized, double-blind trial in the hope that NXY-059 would prove to be a safer alternative to tissue plasminogen activator (tPA) and that it could be offered to more stroke patients. In the study, 3,306 patients with acute ischemic stroke were given a 72-hour infusion of intravenous NXY-059 or placebo within six hours of the onset of stroke symptoms. Both groups had similar rates of mortality and adverse events, and there was no evidence of efficacy for any of the trial's end points. The study was published in the Aug. 9 New England Journal of Medicine.

The study authors did not find any explanation for the difference between this study and the first trial of NXY-059, which found that the drug reduced stroke-related disability. They considered that the discrepancy could have been due to chance and noted the need for additional study. However, the researchers concluded that the most reasonable interpretation of their work is that NXY-059 is ineffective.