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NTIMICROBIAL RESISTANCE IS A serious public threat that is exacerbated by the gradual withdrawal of the pharmaceutical industry from new antimicrobial agent development. 1 Overuse of antimicrobial agents fosters the spread of antimicrobial-resistant organisms. 2,3 Despite recent trends that demonstrate reduced outpatient use of antimicrobial agents, prescribing continues to significantly exceed prudent levels. 4-8 Approximately 50% of courses of ambulatory antimicrobial drugs are prescribed for patients with viral respiratory infections and therefore are not clinically indicated. 9-12 Behavioral facilitators of antimicrobial overuse and barriers to prudent use operate on both clinicians and patients. 13-16 Patient demand, perceived or actual, creates chal-See also pp 2315 and 2354.

IMPORTANCE Metronidazole hydrochloride has historically been considered first-line therapy for patients with mild to moderate Clostridium difficile infection (CDI) but is inferior to vancomycin hydrochloride for clinical cure. The choice of therapy may likewise have substantial consequences on other downstream outcomes, such as recurrence and mortality, although these secondary outcomes have been less studied.OBJECTIVE To evaluate the risk of recurrence and all-cause 30-day mortality among patients receiving metronidazole or vancomycin for the treatment of mild to moderate and severe CDI. DESIGN, SETTING, AND PARTICIPANTSThis retrospective, propensity-matched cohort study evaluated patients treated for CDI, defined as a positive laboratory test result for the presence of C difficile toxins or toxin genes in a stool sample, in the US Department of

This report reviews the clinical uses of surface electromyography (SEMG) as a diagnostic tool for neurologic disorders. SEMG is assessed with regard to the evaluation of patients with neuromuscular diseases, low back pain, and disorders of motor control. This broadens the scope of a previous assessment of SEMG in neurologic practice by the American Association of Electrodiagnostic Medicine 1 in which its utility was examined with regard to neuromuscular diseases only.Needle electromyographic evaluation (NEMG), in combination with nerve conduction studies, is the gold standard methodology for assessing the neurophysiologic characteristics of neuromuscular diseases. Moreover, fine-wire EMG (FWEMG) often has been used in the evaluation of gait disorders, kinesiologic studies, and research and is also considered a standard. Nevertheless, NEMG and FWEMG are both invasive and painful, and this limits their use when activity from several muscles needs to be monitored simultaneously.SEMG is a technique to measure muscle activity noninvasively using surface electrodes placed on the skin overlying the muscle. SEMG differs from NEMG and FWEMG with respect to technical requirements and electrical properties. Unlike NEMG, SEMG electrodes record from a wide area of muscle territory, have a relatively narrow frequency band (range, 20 to 500 Hz), have low-signal resolution, and are highly susceptible to movement artifact. SEMG electrodes typically are approximately 10 mm in diameter and usually are passive (i.e., they are simple conductive surfaces requiring low skin resistance). They can, however, be active, incorporating preamplifier electronics that lessen the need for low skin resistance and improve the signal-to-noise ratio. SEMG can record both voluntary and involuntary muscle activity in addition to externally stimulated muscle action potentials such as motor evoked potentials after central or peripheral nerve stimulation.2 SEMG has also been used in several non-neurologic settings such as obstetric monitoring and animal research, but these potential applications are beyond the scope of this review.More than 2500 original articles, reviews, and books were examined to determine the scope of SEMG utility, its benefits and risks, and the extent to which SEMG techniques vary, and to assess SEMG's strengths and weaknesses for specific clinical applications. Manual and computerized literature searches from the National Library of Medicine were used to obtain the articles. Key words used included SEMG, spontaneous activity, fasciculation, myopathy, muscle fiber conduction, motor unit estimation, fatigue, low-back pain, tremor, movement disorders, reaction time, and psychophysics. Representative articles are cited and listed at the end of this article. Other key words relating to neuromuscular diseases (other than when cross-referenced with SEMG) were not searched for specifically because this topic was the focus of the earlier AAEM assessment 1 and was not the main focus of the current paper. Neuromuscular diseases.No original ...