The generalized propensity score (GPS) is an extension of the propensity score for use withquantitative or continuous exposures (e.g., dose of medication or years of education). Current GPS methods allow estimation of the dose-response relationship between a single continuous exposure and an outcome. However, in many real-world settings, there are multiple exposures occurring simultaneously that could be causally related to the outcome. We propose a multivariate GPS method (mvGPS) that allows estimation of a dose-response surface that relates the joint distribution of multiple continuous exposure variables to an outcome. The method involves generating weights under a multivariate normality assumption on the exposure variables. Focusing on scenarios with two exposure variables, we show via simulation that the mvGPS method can achieve balance across sets of confounders that may dier for dierent exposure variables and reduces bias of the treatment-eect estimates under a variety of data generating scenarios. We apply the mvGPS method to an analysis of the joint eect of two types of intervention strategies to reduce childhood obesity rates. The methods can be implemented using the mvGPS R package available on CRAN.

Objectives: To determine if a sensitive D-dimer assay can exclude progression to organ dysfunction, death, and intensive care unit (ICU) admission in patients presenting to the emergency department (ED) with suspected infection, and if increasing levels of D-dimer are predictive of those end points.

Methods: The study took place at two academic EDs, both located in tertiary care hospitals. This was a prospective convenience sample of adult patients presenting with an infective process and at least two of four criteria for the Systemic Inflammatory Response Syndrome. We measured D-dimer levels in the participants and abstracted their records for the end points. Sensitivity and specificity were calculated and receiver operating characteristic analysis was performed to determine if a higher cutoff would have a greater specificity for our end points.

Results: We enrolled 134 patients. Twelve were excluded from analysis (10 for lack of a D-dimer, one for recent surgery, and one for complete loss to follow up). Using the cutoff of 0.4 established by our laboratories as positive, the D-dimer had a sensitivity of 94% (CI95; 76-99) for organ dysfunction in the ED, 93% (72-99) for organ dysfunction at 48 hours, 93% (81-98) for ICU admission, and 100% (63-100) for 30-day mortality. However, at this cutoff, specificity was not statistically significant. Significantly raising the cutoff for a positive resulted in a decrease in sensitivity but improved specificity.

Conclusion: This study was limited by its nonconsecutive patient recruitment and sample size. A normal D-dimer may exclude progression to organ dysfunction, ICU admission, and death and, at higher cutoff levels, could help risk stratify patients presenting to the ED with signs of sepsis.

[West J Emerg Med. 2010;11(2):173-179.]

Objectives: Cutaneous abscesses are commonly treated in the emergency department (ED). Although incision and drainage (I&D) remains the standard treatment, there is little high quality evidence to support additional interventions such as pain control, type of incision, and use of irrigation, wound cultures, and packing. Although guidelines exist to support clinician management of abscesses, they do not clearly specify these additional interventions. This study sought to describe the ED treatments administered to adults with uncomplicated superficial cutaneous abscesses, defined as purulent lesions requiring incision and drainage, that could be managed in an ED or outpatient setting.

Methods: Four hundred and seventy four surveys were distributed to 15 EDs across the United States. Participants were queried about their level of training and practice environment as well as specific questions regarding their management of cutaneous abscesses in the ED.

Results: In total, 350 providers responded to the survey (74%). One hundred eighty nine respondents (54%) were attending physicians, 135 (39%) were residents and 26 (7%) were mid-level providers. Most providers (76%) used narcotics for pain management, 71% used local anesthetic over the roof of the abscess, and 60% used local anesthetic in a field block for pain control. Only 48% of responders routinely used irrigation after I&D. Eighty-five percent of responders used a linear incision to drain the abscess and 91% used packing in the wound cavity. Thirty two percent routinely sent wound cultures and 17% of providers routinely prescribed antibiotics. Most providers (73%) only prescribed antibiotics if certain historical factors or physical findings were present on exam. Antibiotic treatment, if used, favored a combination of 2 or more drugs to cover both Streptococcus and methicillin-resistant Staphylococcal aureus (47%). Follow up visits were most frequently recommended at 48 hours unless wound was concerning and required closer evaluation.

Conclusion: Variability exists in the treatment strategies for abscess care. The majority of providers used narcotic analgesics in addition to local anesthetic, linear incisions, and packing. Most providers did not irrigate, order wound cultures, or routinely prescribe oral antibiotics unless specific risk factors or physical signs were present. Limited evidence is available at this time to guide these treatment strategies. [West J Emerg Med. 2013;14(1):23–28.]