Evaluating isolation measures for controlling MRSA in hospital settings

¶ … Best Practice to Isolate MRSA Patients in the Hospital Environment

Methicillin-Resistant Staphylococcus Aureus (MRSA) is an anti-microbial organism of concern in the healthcare field; therefore, preventing and controlling its spread within the healthcare environment is a significance function of the infection control experts. One of the preventive measures is isolation of MRSA patients. However, not all are in agreement with such a practice and this makes our topic of discussion raise the question, "Is isolation of MRSA patients in a hospital environment the best practice?"

This reviews aims to evaluate the evidence for the efficiency of isolation measures in managing the prevalence of Methicilin Resistant Staphylococcus Aureus (MRSA) and infection in the hospital environments.

Review Methods: This review relied on scholarly reviewed journals, and selected articles reporting on MRSA related outcomes and illustrating an isolation practice or policy. The paper did not impose quality restrictions on studies employing separation wards or nurse cohorting. In addition, this review utilizes studies, if they showed prospective comparisons of retrospective information.

Results/Discussion: This review accepted 46 studies; 18 using isolation wards, 9 employing nurse cohorting, and 19 had evidence of isolation policies. However, these studies lacked measures to prevent bias, and statistical analysis. In addition, four of the studies provided substantial evidence that intensive control measures including isolation showed efficiency in controlling MRSA.

Conclusion: This review recognizes that major methodological limitations and inadequate reporting in published research showing that the paper includes alternative explanations for reductions in MRSA acquisition linked with interventions.

Introduction

The prevalence of hospital acquired methicillin resistant Staphylococcus auerus (MRSA) continues to rise in the globe hence qualifying as an international health problem (French et al., 2004). The effort to manage the spread of MRSA relies primarily on three measures including hand hygiene among health practitioners (Larson, Quiros and Lin, 2007), restriction of antibiotics, and detection and isolation of infected or colonized patients (Cooper et.al, 2003; Gbanguide-Haore et al., 2008). Perception is that most transmission of MRSA within the hospital environments (French et al., 2004), between patients happens through transiently colonized health workers (Gbanguide-Haore et al., 2008); moreover, airborne transmission through contact with infected or contaminated patients is important for consideration.

The most of the rigorous forms of patient isolation included isolation wards (designed to handle the treatment of known or suspected carriers of MRSA disease) and nurse cohorting, (Talon et al., 2003) (a physical separation of MRSA patients in a part of the ward, with nurses specifically designated to care exclusively for these patients). Into the bargain, other isolation precautions include the use of single bedded patient wards, cohorts of patients on common patient rooms (Talon et al., 2003), which lacked designated staff, and barrier caution (using aprons, gowns, gloves, and masks by healthcare professionals, (Manian and Ponzillo, 2007) as the only physical measure to avoid transmission of MSRA).

However, these control precautions may place significant burden on the hospital resources and the importance of their continued use is in question (Weeber, 2005). Although there are several narrative reviews, the efficiency of isolation measures in reducing transmission and managing MSRA, lacks a systematic evaluation (Hulten et al., 2006). Nevertheless, much of the investigation carried out is quasi-experimental in nature; therefore, there is a need to consider associated threats to valid inferences. This is the primary objective of this paper, to review for evidence on the effectiveness of isolation measures in the management of MRSA within a hospital setting (French et al., 2004).

Method

Search strategy

This review utilizes a search strategy that covers the primary subject areas of the literature review (MRSA, screening, isolation of patients, and control of MRSA infection). The following databases were of significance in this review: Cochrane, TRIP, CINAHL, Medline, National Guidelines Clearing House (NGC), PubMed Clinical Queries, Johanna Briggs and EBSCO. In addition, the review utilized studies published over the year 2000.

Study selection

These review appraised abstracts and it obtained articled if the abstracts mentioned MRSA and an attempt to control it in a hospital environment. Owing to the great number of studies, which it had not anticipated, this review revised the studies that did not impose quality restrictions (Fleming et al., 2006). Therefore, the review imposed the minimum requirement, whereby the accepted studies should include a component of prospective data collection. In addition, if the studies were retrospective, comparisons should show planned and not prompted by part of the data outcome. For the studies incorporating the most rigorous forms of separation (isolation wards and nurse cohorting), lacked such restrictions. This is because such forms of isolation had the greatest influence on hospital resources and organization of services.

Data extraction

This review divided studies into phases appropriately, defining them with major changes in isolation or other elements of infection control policy and extracted data on study design, patient population, isolation facts, screening, other management measures and MRSA related results for patients. In addition, this review documented potential threats to the internal validity of the accepted studies. Therefore, there was consideration of vulnerability on each study selection, performance, and detection and attrition bias (Cooper et al., 2003). Documentation of the measures aimed to prevent bias, noted potential confounders and attempts to record, and adjusts for the measures. In addition, the primary cause of documentation was because of underlying trends, seasonal effects, regression to the average impacts, defined as "the tendency for extreme measurements to be followed by less extreme measurements for imperfectly inked variables that mostly bring about outcomes in wrong conclusions about the impact of interventions." In addition, the review evaluated the appropriateness of any statistical analysis undertaken. This review excludes studies with unclear timing of interventions and main isolation policies.

Type of bias

Cause

Studies vulnerable

Measures to prevent bias

Selection bias

Variation in intervention groups on study entry

Random studies

4-35 interrupted times. Isolation altered presented data allowing for comparison

Performance bias

Variation in care patients apart from interventions under research

Studies with specified element of care was not investigated

One study showed alteration of confounders

Varied length of days

29 interrupted times

Four studies details antibiotic use

Variation in bed occupancy

31 interrupted times

Comparisons in bed occupancy between four

Detection bias

Varied outcome evaluations between intervention groups

All studies

Three studies reported blinding elements of assessors

Variation in diagnosing infections

26 studies

16 of the studies specified diagnostic criteria

Variations in screening measures

10 studies presented colonization data

This suggested that screening efforts could not explain the alterations

Attrition bias

Variations in losses to follow up between the treatment groups

26 studies outcomes with infections

No studies followed up patients after discharge to identify the hospital acquired infections

Data synthesis

This review independently evaluates the strength of evidence in each of the studies by exploring the study design, quality of data, and evidence of plausible alternative explanations of results. In addition, the review characterizes the evidence systematically by basis of "none," "weak," "of intermediate strength," and "stronger." In addition, it considers a formal meta-analysis inadequate due to heterogeneity based on outcome of measures and patient populations.

Results

The electronic search yielded 4,382 abstracts; hand searching did not generate additional papers, the appraisal of abstracts chose 254 papers, including 20 in foreign languages other than English. However, the final review involved 46 studies (Cooper et al., 2003).

Characteristics of the accepted studies

Highest level of separation

Isolation ward

Nurse cohorting

Other isolation precautions

No of studies

18

9

19

Range of study time

3 months-15 years

3.5months-4 years

1 monht-9 years

Entire hospital setting

16

3

7

Unit setting in each hospital

2

6

12

Other Control Measures

Screening

18

9

14

Topical eradication therapy

12

5

8

Hand hygiene

8

2

6

Antibiotic restriction

3

0

2

Study Design

Prospective interrupted time series

1

2

8

Retrospective interrupted time series

15

3

2

Hybrid retrospective and prospective time series

0

2

1

Retrospective cohort study

0

0

1

Non-comparative studies

2

2

3

Study Design

These review doses not find randomized trials and only four retrospective planned comparisons with predefined phases of the study (Mody et al., 2003). In most of the studies, designs faced interruptions time series, meaning time series of results measures recorded before one or more interventions. Moreover, eight of the 38 interrupted time series studies presented only collapsed information, analyzing the time series from both segment in a distinct data top. In addition, one retrospective cohort research used survey data from Dutch healthcare facilities (Talon et. al., 2003). Some ten studies did not weigh against isolation or screening measures with regard to separation or screening. A review of the 36 studies that allowed for comparisons between isolation policies showed that in 27 of the comparison, they had independence on knowledge of the data results. However, short retrospective studies with successful results were vulnerable to this challenge.

Summary of evidence

Most of the evidences offered in each study were descriptive rather than quantitative. In additional, formal meta-analysis of outcomes was inappropriate owing to the diverse settings and outcome precautions. Therefore, this review does not evaluate data using appropriate statistical techniques. In most studies, there was a report of insufficient data allowing for further evaluations. Although some studies illustrated time series, these time series are only appropriate from continuous results, and count data only when the numbers are large to justify a continuation. This calls for a formal time evaluation to varied approaches in analyzing the time series because count data typically arise from epidemics within the hospital setting.

Constraints of this review

Some of the process limitations included restricting number of the searched databases and ignoring an investigation for grey literature. In addition, the time may have led to missing of some evidences. Review of this paper involves an individual; therefore, it needs some evaluation in order to ensure accuracy of quality evaluations on all data extracted. In addition, in the search, some foreign papers came up, but it was not possible to evaluate for quality (Cooper et al., 2003). Another challenge is that, it was not possible to contact authors in order to identify or verify missing information.

Study Quality

Some recent studies focusing on the utilization of patient isolation for the control of nosocomical MRSA and an additional review that focused on the infection management of MRSA within a hospital setting conclude that the current measures in this field is weak. The additional studies identified by the present review in the field of isolation of MRSA patients, were predominantly observational researches incorporating illustrative designs that assessed multiple interventions. In addition, most of the studies were inadequate because of methodological flaws. For instance, only two studies reported several phases of data collection, more than one methods of data collection. Currently, there is inadequate good quality empirical evidence in using tropical or systematic antimicrobial therapy for eradicating nasal or extra nasal MRSA. Overall, some current studies all along provide substantial support that the isolation or cohorting of MRSA patients or colonization (Graham, Lin and Larson, 2006) may play a significant role in reducing its transmission.

Future Research

Future research should concentrate on collecting adequate data and approximation of key elements in this field. In addition, such data should allow evaluation of existing models to enhance comparison with models making varied assumptions (Cooper et al., 2003). In so doing, the resulting calibrated models should serve as adequate tools for predicting, examining other measures, performing economic analysis and construct cost effective precautions.

Implications for healthcare

The literature review found evidence that intensive isolation can significantly reduce MRSA, even in environments with high levels of endemic MRSA. In addition, it is significant to note that little evidence was found to comment that current isolation precautions are inefficient and they should be used unless further research establishes otherwise. The general isolation method applied is the single-room isolation with cohorting in bays when necessary, because resources might lack. In addition, the current MRSA management guidelines describe control options dependent on the patient's group, MRSA endemic, plus availability of isolation structures. Research, however, suggests that a major constraint in all these options reflect unreliable data for individual patient groups. Therefore, the whole hospital population should prioritize modeling the whole hospital population.

Modeling outcomes commented that control of MRSA by detection and isolation is feasible over varied environments. Moreover, modeling results demonstrate that some isolation policies may fail if inadequately managed and resource; therefore, there is a need to review MRSA management strategies by hospitals. Some few studies provided brief information on significant modifiers such as occupancy, staffing levels, antibiotic usage hand hygiene and patients on colonization (Larson, Quiros and Lin, 2007; Graham, Lin and Larson, 2006). Hospitals should consider incorporating audit resources to information technology for systematic collection and evaluation of information. In addition, this could help in organizing interventions and interpreting their impacts. In addition, such an audit system will need a careful design, piloting and validation.

Conclusion

This literature review has several merits over previous literature reviews on this topic. Therefore, since it has aspects of systematic, it should not be prone to prejudices or biases in a study selection. For instance, the search strategy and data extraction is highly comprehensive. In addition, this review also provides implications and allows future research by offering substantial considerations. In addition, it is essential to note that an efficient hand hygiene program (Larson, Quiros and Lin, 2007), in combination with single-room isolation, screening and eradication (Dupeyron et al., 2002), could work well in reducing MRSA levels and infection even though it had an initial high level. Although some studies provided inadequate evidence that did not offer substantial support on isolation measures, other studies provide detailed information that support isolation as a best practice.