Cost-effectiveness and clinical utility of universal pre-admission MRSA screening in total joint arthroplasty patients.

BACKGROUND: For patients undergoing total joint arthroplasty (TJA), pre-admission meticillin-resistant Staphylococcus aureus (MRSA) nasal screening has been widely adopted to prevent postoperative joint infection. However, screening cost-effectiveness and clinical utility have not been adequately evaluated. AIM: To assess the MRSA infection rate, associated costs, and costs of screening at our institution, before and after screening implementation. METHODS: This was a retrospective cohort study examining patients who underwent TJA at a health system in New York State, between 2005 and 2016. Patients were divided into the 'no-screening' group if the operation occurred prior to adoption of the MRSA screening protocol in 2011 and the 'screening' group if afterwards. The number of MRSA joint infections, cost of each infection, and costs associated with preoperative screening were recorded. Fisher's exact test and cost comparison analysis were performed. FINDINGS: The no-screening group had four MRSA infections in 6088 patients over a seven-year period, whereas the screening group had two in 5177 patients over five years. Fisher's exact test showed no significant association between screening and MRSA infection rate (P = 0.694). The cost of postoperative MRSA joint infection treatment was US$40,919.13 per patient, whereas annual nasal screening was US$103,999.97. CONCLUSION: At our institution, MRSA screening had little impact on infection rates and led to increased costs, with 2.5 MRSA infections required annually to meet the costs of screening. Therefore, the screening protocol may be best suited for high-risk populations, rather than the average TJA patient. The authors recommend a similar clinical utility and cost-effectiveness analysis at other institutions implementing MRSA screening programmes.

Comparison of QCA systems.

AIMS: Excellent agreement between different 'second generation' systems for quantitative coronary arteriography (QCA) has been found in in vitro measurements. To verify the quality and stability of QCA when used in clinical practice, three QCA systems (AWOS, Cardio, and CMS) were used in a representative set of coronary artery lesions. METHODS AND RESULTS: This set consisted of angiographic stenosis images of 57 patients which varied in stenosis severity and morphology. The process of image acquisition, calibration, and measurement was strictly standardized to eliminate procedural sources of error. Three observers performed QCA five times in each lesion with each QCA system. Interobserver variability was low (Dnorm 0.01-0.05 mm, Dmin 0.01-0.02 mm, %stenosis 0.3-0.7%). Values of system precision were excellent (Dnorm 0.11-0.13 mm, Dmin 0.04-0.06 mm, %stenosis 2.1-2.6%). Comparison of measurements between three QCA systems revealed good agreement (range of mean differences for Dnorm 0.03-0.12 mm, Dmin 0.04-0.11 mm, and %stenosis 0.5-3.6%) and high correlation (corr 0.902-0.977). There was a tendency to measure smaller values for Dmin and consequently to identify more severe stenoses with the AWOS system than with the Cardio and CMS systems. All QCA results were compared to measurements done with the Brown Dodge method to reveal failure of the QCA measurements. These results showed excellent agreement without any systematic deviation (mean differences for Dnorm 0.01-0.08 mm, Dmin 0.02-0.06 mm, and %stenosis 1.3-1.8%). None of the differences were statistically significant. CONCLUSION: We therefore conclude that using the defined version of the AWOS, Cardio, and CMS systems, there is no difference in precision or accuracy when used for QCA of coronary artery lesions.

[Effect of qualitative stenosis characteristics on the quality of measurements of various QCA systems]. / Einfluss von qualitativen Stenosecharakteristika auf die Messqualität verschiedener QCA-Systeme.

Reproducibility and accuracy of in vitro measurements are very high using recently developed QCA systems. We analyzed the impact of lesion characteristics ad the image quality on the quality of measurements under clinical conditions. For the study we selected 57 coronary artery lesions which had a clinically relevant distribution for stenosis severity, lesion characteristics, and image quality. Every effort was made to eliminate procedural sources of error. Three investigators measured each lesion five times with each of three QCA systems (AWOS, Cardio and CMS). Only the measurements of the minimal stenosis diameter were analyzed. The precision of all the measurements was high with the AWOS (0.04 mm), the Cardio (0.05 mm), and the CMS systems (0.06 mm). Variability of measurements increased for the following criteria: Ambrose-III morphology (CMS 0.082 mm), surface irregularities (Cardio 0.069 mm, CMS 0.073 mm), TIMI I (Cardio 0.084 mm, CMS 0.0121 mm), and moderate image quality (CMS 0.07 mm). There were no differences in the precision of the measurements in the other groups of lesion characteristics. There were no relevant differences in any of the measurements between the systems (AWOS-Cardio -0.07 mm, AWOS-CMS-0.11 mm, Cardio-CMS-0.04 mm). Smaller diameters were measured with the AWOS system than with the CMS and the Cardio systems when the lesion was calcified (AWOS-Cardio-0.109 mm, AWOS-CMS-0.161 mm). This was only a trend, however, and did not reach statistical significance, which was also true for the other differences found between the systems according to various lesion characteristics. In summary, we found that the measurement quality of the QCA systems used in this study is not altered by the underlying lesion characteristics or the image quality.

Clinical significance of neutropenia in patients with human immunodeficiency virus infection.

OBJECTIVE: To determine the incidence of infection in human immunodeficiency virus (HIV)-infected patients during periods of neutropenia and non-neutropenia. To compare the infection rates in patients with HIV disease to those in a group hospitalized with neutropenia and hematologic malignancy. DESIGN: Prospective observational study conducted between December 1985 and December 1987 at a university teaching hospital. Thirty patients with documented acquired immunodeficiency syndrome (AIDS) and absolute T-helper cells less than 200 mm/mm3. All patients had a period of non-neutropenia following a neutropenic period (neutrophils less than 1000 cells/mm3). RESULTS: The rate of first infection during neutropenic and non-neutropenic periods for opportunistic infection and nonopportunistic infections were compared. There were no differences between infection rates for the two time periods for both types of infections. A subgroup of patient care days in which non-neutropenic days followed neutropenic days also was studied to eliminate selection bias. In this group, a comparison of infection rates also revealed no difference between neutropenic and non-neutropenic periods. An alternate analysis of the time until first infection during periods of neutropenia or non-neutropenia was done using the Kaplan-Meier product limit method. There was a longer infection-free period for the neutropenic group for opportunistic infections, but it was not statistically significant (p less than .1). In addition, we compared HIV-infected patients with a group of 37 patients with neutropenia from hematologic malignancy. There was a significantly higher rate of all infections, particularly bacteremias (p less than .001), in the group of patients with hematologic malignancies when compared with all subsets of patients with HIV disease. CONCLUSION: We conclude that patients with HIV disease and modest neutropenia do not have an increased risk of bacterial infection. The incidence of all infections is significantly greater in patients with neutropenia secondary to hematologic malignancy.