Dataset Information

Categorisation of continuous risk factors in epidemiological publications: a survey of current practice.

ABSTRACT:

Background

Reports of observational epidemiological studies often categorise (group) continuous risk factor (exposure) variables. However, there has been little systematic assessment of how categorisation is practiced or reported in the literature and no extended guidelines for the practice have been identified. Thus, we assessed the nature of such practice in the epidemiological literature. Two months (December 2007 and January 2008) of five epidemiological and five general medical journals were reviewed. All articles that examined the relationship between continuous risk factors and health outcomes were surveyed using a standard proforma, with the focus on the primary risk factor. Using the survey results we provide illustrative examples and, combined with ideas from the broader literature and from experience, we offer guidelines for good practice.

Results

Of the 254 articles reviewed, 58 were included in our survey. Categorisation occurred in 50 (86%) of them. Of those, 42% also analysed the variable continuously and 24% considered alternative groupings. Most (78%) used 3 to 5 groups. No articles relied solely on dichotomisation, although it did feature prominently in 3 articles. The choice of group boundaries varied: 34% used quantiles, 18% equally spaced categories, 12% external criteria, 34% other approaches and 2% did not describe the approach used. Categorical risk estimates were most commonly (66%) presented as pairwise comparisons to a reference group, usually the highest or lowest (79%). Reporting of categorical analysis was mostly in tables; only 20% in figures.

Conclusions

Categorical analyses of continuous risk factors are common. Accordingly, we provide recommendations for good practice. Key issues include pre-defining appropriate choice of groupings and analysis strategies, clear presentation of grouped findings in tables and figures, and drawing valid conclusions from categorical analyses, avoiding injudicious use of multiple alternative analyses.

SUBMITTER: Turner EL

PROVIDER: S-EPMC2972292 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Categorisation of continuous risk factors in epidemiological publications: a survey of current practice.

Turner Elizabeth L EL Dobson Joanna E JE Pocock Stuart J SJ

Epidemiologic perspectives & innovations : EP+I 20101015

<h4>Background</h4>Reports of observational epidemiological studies often categorise (group) continuous risk factor (exposure) variables. However, there has been little systematic assessment of how categorisation is practiced or reported in the literature and no extended guidelines for the practice have been identified. Thus, we assessed the nature of such practice in the epidemiological literature. Two months (December 2007 and January 2008) of five epidemiological and five general medical jour ...[more]

PMID: 20950423

Similar Datasets

Project description:BackgroundThe number of blood tests ordered in primary care continues to increase and the timely and appropriate communication of results remains essential. However, the testing and result communication process includes a number of participants in a variety of settings and is both complicated to manage and vulnerable to human error. In the UK, guidelines for the process are absent and research in this area is surprisingly scarce; so before we can begin to address potential areas of weakness there is a need to more precisely understand the strengths and weaknesses of current systems used by general practices and testing facilities.MethodsWe conducted a telephone survey of practices across England to determine the methods of managing the testing and result communication process. In order to gain insight into the perspectives from staff at a large hospital laboratory we conducted paired interviews with senior managers, which we used to inform a service blueprint demonstrating the interaction between practices and laboratories and identifying potential sources of delay and failure.ResultsStaff at 80% of practices reported that the default method for communicating normal results required patients to telephone the practice and 40% of practices required that patients also call for abnormal results. Over 80% had no fail-safe system for ensuring that results had been returned to the practice from laboratories; practices would otherwise only be aware that results were missing or delayed when patients requested results. Persistent sources of missing results were identified by laboratory staff and included sample handling, misidentification of samples and the inefficient system for collating and resending misdirected results.ConclusionsThe success of the current system relies on patients both to retrieve results and in so doing alert staff to missing and delayed results. Practices appear slow to adopt available technological solutions despite their potential for reducing the impact of recurring errors in the handling of samples and the reporting of results. Our findings will inform our continuing work with patients and staff to develop, implement and evaluate improvements to existing systems of managing the testing and result communication process.

Project description:ObjectivesTo evaluate the extent and quality of patient involvement reporting in examples of current practice in health research.DesignMixed-methods study. We used a targeted search strategy across three cohorts to identify health research publications that reported patient involvement: original research articles published in 2019 in the British Medical Journal (BMJ), articles listed in the Patient-Centered Outcomes Research Institute (PCORI) database (2019), and articles citing the GRIPP2 (Guidance for Reporting Involvement of Patients and Public) reporting checklist for patient involvement or a critical appraisal guideline for user involvement. Publications were coded according to three coding schemes: 'phase of involvement', the GRIPP2-Short Form (GRIPP2-SF) reporting checklist and the critical appraisal guideline.Outcome measuresThe phase of the study in which patients were actively involved. For the BMJ sample, the proportion of publications that reported patient involvement. The quality of reporting based on the GRIPP2-SF reporting guideline. The quality of patient involvement based on the critical appraisal guideline. Quantitative and qualitative results are reported.ResultsWe included 86 publications that reported patient involvement. Patients were most frequently involved in study design (90% of publications, n=77), followed by study conduct (71%, n=61) and dissemination (42%, n=36). Reporting of patient involvement was often incomplete, for example, only 40% of publications (n=34) reported the aim of patient involvement. While the methods (57%, n=49) and results (59%, n=51) of involvement were reported more frequently, reporting was often unspecific and the influence of patients' input remained vague. Therefore, a systematic assessment of the quality and impact of patient involvement according to the critical appraisal guideline was not feasible across samples.ConclusionsAs patient involvement is increasingly seen as an integral part of the research process and requested by funding bodies, it is essential that researchers receive specific guidance on how to report patient involvement activities. Complete reporting builds the foundation for assessing the quality of patient involvement and its impact on research.

Dataset Information

Categorisation of continuous risk factors in epidemiological publications: a survey of current practice.

Background

Results

Conclusions

Publications

Categorisation of continuous risk factors in epidemiological publications: a survey of current practice.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets