The ORION statement: guidelines for transparent reporting of outbreak reports and intervention studies of nosocomial infection

Summary

The quality of research in hospital epidemiology (infection control) must be improved to be robust enough to influence policy and practice. In order to raise the standards of research and publication, a CONSORT equivalent for these largely quasi-experimental studies has been prepared by the authors of two relevant systematic reviews, following consultation with learned societies, editors of journals, and researchers. The ORION (Outbreak Reports and Intervention Studies Of Nosocomial infection) statement consists of a 22 item checklist, and a summary table. The emphasis is on transparency to improve the quality of reporting and on the use of appropriate statistical techniques. The statement has been endorsed by a number of professional special interest groups and societies. Like CONSORT, ORION should be considered a “work in progress”, which requires ongoing dialogue for successful promotion and dissemination. The statement is therefore offered for further public discussion. Journals and research councils are strongly recommended to incorporate it into their submission and reviewing processes. Feedback to the authors is encouraged and the statement will be revised in 2 years.

Introduction

The move towards evidence-based medicine has gained momentum this past decade. The publication of the CONSORT (Consolidated Standards of Reporting Trials) statement in 1996,¹ its revision in 2001,² and extension in 2004,³ which sought to improve the quality of reports of randomised controlled trials (RCTs), has contributed to this. Through its insistence on complete transparency of reporting, the statement has enabled editors and readers to understand exactly why and how an individual RCT was designed, conducted, and analysed, and to assess the threats to the validity of its results.

The recent publication of the TREND statement (Transparent Reporting of Evaluations of Nonrandomised Designs) sought to do for public-health interventions—most of which are described in non-randomised studies—what CONSORT has achieved for the RCT.⁴ The TREND statement adapted the CONSORT statement, its checklist of descriptors, and its flow diagram, but with revisions relevant to non-randomised designs and some important enhancements relevant to RCTs evaluating public-health interventions. Transparency was key to improving the quality of reporting so that information critical to synthesis of research was not missing.⁵ The current STROBE initiative (Strengthening the Reporting of Observational studies in Epidemiology) seeks to do the same for epidemiological research, especially for cohort, case control, and cross-sectional studies (http://www.strobe-statement.org).

Hospital interventions to control the rising levels of antimicrobial resistance and healthcare-associated (nosocomial) infections form a large body of non-randomised studies. Systematic reviews of isolation policies in the hospital management of meticillin-resistant Staphylococcus aureus (MRSA)6, 7 and of interventions to improve antibiotic prescribing to hospital inpatients8, 9 revealed major methodological weaknesses and inadequate reporting in published research. These included lack of details on study design, as others have noted,¹⁰ the timing and nature of interventions, failure to consider threats to validity of inference in the form of potential confounders and biases, and inappropriate statistical analyses. Studies were largely quasi-experimental and often basic information such as the number of isolation beds, criteria to diagnose infection, culture and typing of organisms, or the timing of interventions were missing. Guidelines for the publication of future outbreak reports and intervention studies were produced,⁶ informed by theoretical considerations,¹¹ but although available on-line (http://www.hta.nhsweb.nhs.uk), these refer primarily to MRSA and are not as user-friendly as the revised CONSORT statement with its 22 item checklist and flow diagram. Moreover, the CONSORT, TREND, and STROBE statements do not provide items or descriptors easily translatable into the wide variety of interventions, settings, designs, and statistical issues relating to infectious diseases.

The authors of the two systematic reviews of isolation⁶ and antibiotic prescribing⁸ therefore modified previous guidelines⁶ for the publication of MRSA outbreak reports and intervention studies to make them relevant to nosocomial organisms in general and to take account of issues pertinent to evaluation of interventions to change hospital antibiotic prescribing.8, 9 The resultant ORION (Outbreak Reports and Intervention Studies Of Nosocomial infection) statement is written in the spirit of the CONSORT and TREND statements, taking into account the variety of interventions, settings, designs, and statistical issues pertinent to health-care associated infections, with team members reaching consensus agreement through repeated email correspondence and telephone conversations. The statement was then put out to consultation with learned societies, editors of journals, and many researchers, acknowledged below, whose responses have been taken into account in the revised statement. The statement is designed especially for quasi-experimental (ie, non-randomised) study designs commonly used in hospital epidemiology: interrupted time series with and without control groups, and outbreak reports.

The interrupted time series is the predominant study design for infectious disease epidemiology, especially in the hospital setting. Outcome measures are not independent, which introduces specific threats to the validity of inferences, which have had to be addressed. Much research into nosocomial infections blurs the distinction between formal studies and outbreak reports, planned and unplanned comparisons. The guidelines attempt to address this problem by emphasising precision and thoroughness in reporting: as well as the usual what was done and when it was done for such quasi-experimental research, it is also important to know why interventions and particular comparisons were made. As in the TREND statement, “transparency is key” and the ORION items and descriptors “type of paper”, “design”, and “dates” have been added to ensure this, since even such basic details are often lacking in the hospital infection literature.6, 7, 8, 9

Our aims in producing these guidelines are to raise the standards of research and publication in hospital epidemiology, to facilitate synthesis of evidence and promote transparency of reporting, to enable readers to relate studies to their own experience, and to assess the degree to which results can be generalised to other settings. The guidelines are aimed at researchers, editors, reviewers, and grant assessment panels. It is intended that the guidelines facilitate well-designed interventional studies to help choose which methods are effective in reducing antimicrobial resistance or health-care associated infections.