Monthly Archives: June 2014

Urinalysis in asymptomatic patients before joint replacement is a waste

POEMs Research Summaries

Clinical Question

Should asymptomatic patients have a routine urinalysis before undergoing total joint replacement surgery?

Bottom Line

Asymptomatic patients undergoing total joint replacement have a low rate (5%) of symptomatic urinary tract infections (UTIs) during the 3 months following surgery. This low rate supports discontinuing routine preoperative urinalyses in asymptomatic patients. (LOE = 1b)

Reference

Bouvet C, Lübbeke A, Bandi C, et al. Is there any benefit in pre-operative urinary analysis before elective total joint replacement? Bone Joint J 2014;96-B(3):390-394.
Study Design: Cohort (prospective)
Funding: Self-funded or unfunded
Setting: Inpatient (any location) with outpatient follow-up
Allocation: Unknown

Synopsis

These authors evaluated patients undergoing elective total joint replacement (knees or hips) at a single Swiss university. The authors report that their practice is to perform a urinalysis before surgery, but they questioned whether this practice should continue. After excluding patients with symptoms of UTIs or chronic indwelling catheters, they identified 504 patients undergoing 510 surgeries. All patients received a single parenteral dose of cefuroxime or vancomycin perioperatively. The researchers evaluated the patients on day 3 and month 3 after surgery. Most of the patients (61%) were women; the mean age was 69 years (range = 16 to 97 years). Approximately 33% of the patients had a positive urine culture before surgery and 41% had a positive urine culture on the third day after surgery. However, only 5% of patients (n = 25) developed a symptomatic UTI after surgery or during the 3 months after. Additionally, most UTIs were secondary to pathogens unrelated to the initial cultures. This study, like many others, questions a routine preoperative test. The low rate of symptomatic UTIs and the lack of correlation with any surgical infectious complications in this study reinforces this literature base. One caveat: This is not a randomized trial, so we can’t really say that patients are truly better off with or without routine testing. The authors had hoped to do a randomized trial, but estimated it would take bazillions of patients to pull it off!

Henry C. Barry, MD, MS
Professor
Michigan State University
East Lansing, MI

 

 

 

 

 

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Detecting colorectal cancer: Accuracy of stool DNA and immunochemical tests

POEMs Research Summaries

Clinical Question:  How accurate are the new fecal DNA and fecal immunochemical tests as screening tests for colorectal cancer?

Bottom Line:

Fecal DNA is more sensitive but less specific than fecal immunochemical testing (FIT), and as a result has a higher false positive rate. The fecal DNA test is also more expensive than other noninvasive alternatives such as FIT. We do not know which test will be better at reducing mortality. (LOE = 2b)

Reference

Imperiale TF, Ransohoff DF, Itzkowitz SH, et al. Multitarget Stool DNA Testing for Colorectal-Cancer Screening. N Engl J Med 2014;370(14):1287-1297.

Study design:  diagnostic test evaluation

Funding: Industry

Setting: Outpatient

Allocation: unknown

Synopsis

Fecal DNA testing looks for abnormalities characteristic of the DNA in colorectal cancer (CRC), while fecal immunochemical testing (FIT) is an improved version of the older tests that detect fecal occult blood but only requires a single stool specimen. Adults aged 50 years to 85 years, at average risk for CRC, who were undergoing screening colonoscopy were invited to participate in the study. A total of 11,016 agreed, and underwent the required tests. Of that group, 689 were excluded because of an insufficient specimen for fecal DNA or a specimen that leaked in shipping (ick!), 304 others were excluded because of inadequate colonoscopy, and 34 had an insufficient sample for FIT. Of the final group of 9989 participants, 65 received a diagnosis of cancer. Fecal DNA testing was 92% sensitive and 87% specific, while FIT was 74% sensitive and 95% specific. Although this looks like a clear advantage for fecal DNA (60 of 65 cancers detected, compared with 48 of 65 for FIT), it is important to look a bit further. The lower specificity for fecal DNA meant that there were nearly 3 times as many false positive results that would have required a follow-up colonoscopy if fecal DNA was the sole screening test (1231, vs 472 for FIT). Using fecal DNA, there would have been 22 colonoscopies per cancer detected, compared with 11 using FIT. Also, fecal DNA testing requires the entire stool specimen, collected using a small bucket that hangs in the toilet, and costs approximately $400 to $800 (FIT costs approximately $3 to $40). Remember, because CRC takes several years to progress from adenoma to cancer, a FIT test could be performed annually at a much lower cost and likely detect many of the initially missed cancers in subsequent years.

Mark H. Ebell, MD, MS
Associate Professor
University of Georgia
Athens, GA

 

 

 

 

 

 

 

Meta-analysis of RCTs of “health checks” — limited data on effectiveness

Clinical Question

How effective are periodic comprehensive health assessments (“health checks”) in primary care?


Bottom Line:

The existing body of research on periodic comprehensive health assessments is not able to determine if these “health checks” are meaningful. (LOE = 1a-)

Reference

Si S, Moss JR, Sullivan TR, Newton SS, Stocks NP. Effectiveness of general practice-based health checks: a systematic review and meta-analysis. Br J Gen Pract 2014;64(618):e47-e53.

Study Design: Meta-analysis (other)

Funding: Government

Setting: Outpatient (primary care)

Allocation: Unknown

Synopsis

These authors searched several databases, as well as the Cochrane Central Register of Controlled Trials, to identify English-language randomized trials (randomized, cluster-randomized, pseudo-randomized) that compared the health outcomes of general practice-based health checks versus usual care in middle-aged participants. The authors don’t specify how they determined study inclusion, or if the data extraction and quality assessment of included studies was done in a masked and independent manner. Ultimately, they included 6 studies. The authors don’t report how many patients were included or the duration of follow-up in these studies. Virtually all the studies evaluated surrogate measures (eg, blood pressure, cholesterol, and so forth). The studies generally had significant sources of bias: lack of masking, high loss to follow-up, selection bias. Although the authors present a variety of improvements in surrogate markers, none are really clinically important. The authors reported no difference in overall mortality.

Henry C. Barry, MD, MS
Professor
Michigan State University
East Lansing, MI