File Name: inclusion and exclusion criteria in research .zip
A cross-sectional multicenter study evaluated self-reported adherence to inhaled therapies among patients with COPD in Latin America. The authors concluded that suboptimal adherence to inhaled therapies among COPD patients was common and that interventions to improve adherence are warranted. Establishing inclusion and exclusion criteria for study participants is a standard, required practice when designing high-quality research protocols.
Department of Onco-anaesthesiology and Palliative Medicine, Dr. The conduct of research requires a systematic approach involving diligent planning and its execution as planned. These need to be objective, reliable and in a repeatable format. Hence, the understanding of the basic aspects of methodology is essential for any researcher.
Metrics details. Low back pain is a common health complaint resulting in substantial economic burden. Each year, upwards of 20 randomised controlled trials RCTs evaluating interventions for non-specific low back pain are published. Use of the term non-specific low back pain has been criticised on the grounds of encouraging heterogeneity and hampering interpretation of findings due to possible heterogeneous causes, challenging meta-analyses. We explored selection criteria used in trials of treatments for nsLBP.
Study inclusion and exclusion criteria were extracted, thematically categorised, and then descriptive statistics were used to summarise the prevalence by emerging category. We included studies. Two inclusion themes anatomical area, and symptoms and signs were identified. Exclusion criteria comprised 21 themes. RCTs of interventions for non-specific low back pain have incorporated diverse inclusion and exclusion criteria. Guidance on standardisation of inclusion and exclusion criteria for nsLBP trials will increase clinical homogeneity, facilitating greater interpretation of between-trial comparisons and meta-analyses.
We propose a template for reporting inclusion and exclusion criteria. Peer Review reports. Low back pain LBP is a common and costly problem resulting in a substantial personal, social and economic burden globally [ 1 , 2 ]. Low back and neck pain are ranked fourth in terms of disability-adjusted life years, and the leading cause of activity limitation and work absence globally [ 2 , 3 , 4 ]. Most episodes of LBP are self-limiting and not related to serious disease [ 5 , 7 ].
The term has no agreed definition despite being used by organisations such as the World Health Organization, International Association for the Study of Pain, Backpain Europe, and the UK National Institute for Health and Care Excellence [ 7 , 9 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. The annual rate of publication for randomised controlled trials RCTs that test interventions for people with nsLBP has increased from an average of 5.
Interpretation of the results of these numerous RCTs, requires a good understanding of the study populations that have been included. Similarly, to synthesise the results of RCTs in meta-analyses requires study populations to be reasonably homogeneous across trials. Study populations are determined by the selection or eligibility inclusion and exclusion criteria that form the framework for sampling [ 24 ]. Little research has examined inclusion and exclusion criteria used in RCTs of LBP populations [ 24 , 25 , 26 ]; studies that did, found ambiguous identification of neurological involvement in the selection criteria, and inconsistencies across clinical decision guidelines for LBP.
The extent to which trialists have used a consistent approach to identifying people with nsLBP is currently unclear. As part of a larger study systematically reviewing RCTs of treatment for non-specific LBP, the aims relevant to this paper were to systematically describe the inclusion and exclusion criteria reported in RCTs that test interventions for nsLBP, the frequency of reporting criteria and to classify criteria by theme [ 23 ].
Research methods in low back pain research have developed over recent decades. Two of three reviewers PB, DR or TB , working independently, identified all candidate RCT reports by combining all database hits in an Endnote Version 14; Thomson Reuters, Philadelphia library, removing duplicates, and short-listing by title and abstract.
Additionally, the inclusion criteria might be different because the aims may be different [ 27 ]. Further, the inherent problem with low power due to the small sample sizes used, may not be able to be overcome using meta-analytical techniques due to the assumptions about underlying distributions being unrealistic [ 28 ].
Two of three reviewers PB, DR or TB independently extracted data on inclusion and exclusion criteria reported in the methods section of each included trial. One reviewer PA entered these data into a database. To identify the categories of reported inclusion and exclusion criteria, we developed a coding framework with themes and subthemes.
PA, RF and DR first familiarised themselves with the extracted data and coded each inclusion and exclusion criterion with labels that described their focus, and then grouped these coded data into clusters of similar interrelated ideas or concepts to form general categories. We retained the terminology used within RCT reports, aiming to describe the verbatim terms used. However, decisions needed to be made during the process regarding criteria that could be conflated e.
These decisions were made through team discussion and the framework was revised and refined until all the coded data could be modelled within the structure of the framework. We populated each theme and subtheme of our framework with frequencies of reporting. Frequency distributions were used to summarise the prevalence of reported criterion. Our initial search identified studies; we examined full-texts of of these. At full-text level, articles were excluded [50—], and met the inclusion criteria [—] Fig.
While most studies reported the age, gender and symptom duration of their study population, these demographics were variably included as inclusion criteria. While some trial reports were specific when describing pain symptoms e. Themes one to 12 i. Specific conditions were the most commonly described exclusion criteria.
Symptoms and signs included as exclusion criteria were mostly neurological or inferred neurological conditions. Trial reports provided relatively fewer details for inclusion criteria than they did for exclusion criteria. However, exclusion of malignancy in the remaining trials may have been assumed to be implied by the definition of nsLBP. While most trials reported specific pathologies as exclusion criteria, many of the terms used to describe these were ambiguous or vague, making it difficult to ascertain how these were operationalised.
Psychological conditions were reported as exclusion criteria in one-third of trials, which is a surprising finding when the literature proposes that psychological disorders may be a predictor of chronicity in LBP as well as comorbid with pain [ 31 , 32 , 33 ]. Use of umbrella or over-arching terms, without specific descriptions of what these were, was frequently seen across all categories of symptoms, signs, and conditions.
Our findings demonstrate the heterogeneity of the selection criteria of RCTs purporting to be studying similar populations. The application of these criteria is typically poorly described, creating difficulty for making judgements on the comparability of study populations. Explicit reporting of clearly defined inclusion and exclusion criteria, using consistent terminology, would increase our confidence in the clinical homogeneity of nsLBP trial populations, increase the validity of meta-analyses, and improve our ability to interpret and compare the results of individual RCTs and systematic reviews.
RCTs that include or exclude people without clear diagnostic criteria or procedure, could lead to including individuals with different prognoses.
Without clear, unambiguous descriptions, the utility of reporting exclusion criteria is limited. For example, intervertebral disc herniation is evident in many asymptomatic individuals, and it may often be the case that participants with asymptomatic herniations are admitted into a trial [ 35 , 36 ]. Of the subthemes of selection criteria that we judged as particularly relevant to back pain, there was inconsistent application between RCTs.
Psychosocial conditions were often reported; however, yellow flags were only reported within the selection criteria of one trial [ 37 ]. Selection criteria depend on the intervention being tested; there may be good reason for disproportionate focus on biological, psychological or sociological factors.
Notwithstanding, over recent decades psychosocial aspects of low back pain have gained much attention [ 38 ]. Studies have highlighted the importance of psychosocial factors in the transition from acute to chronic pain; however, we note that few trials used questionnaires designed to assess psychological aspects of pain in relation to the selection of suitable participants for nsLBP trials [ 38 , 39 , 40 , 41 ].
Research on criteria for participating in trials has investigated case definitions and duration of LBP, and specific inclusion and exclusion criteria e. These studies show ambiguous presentation of case definitions, duration, and a variation in reported criteria and diagnostic criteria specifically for exclusion of neurological conditions [ 18 , 25 , 42 ]. These results are consistent with our findings.
Similar ambiguities have also been described by systematic reviews of trials of interventions for treatment of conditions of the shoulder [ 43 , 44 ] and neck [ 45 ]. We hope that this work will be useful in starting and informing discussion surrounding consensus on appropriate entry criteria and what constitutes sufficient detail to adequately describe cLBP study populations. This review utilised a systematic multi-reviewer approach and methods developed a priori to review and categorise the selection criteria in nsLBP RCTs.
The review has several limitations, which must be acknowledged. The trials investigated were published between and ; thus, more recently published reports are not represented. Our view is that there is no reason to expect that any large recent change in entry criteria would materially change our findings. The Task Force Report on Research Standards for Chronic Low-Back Pain was published in and emphasised the variation in inclusion and exclusion criteria, which may have influenced nsLBP trial investigators to become increasingly aware of describing criteria more homogenously [ 24 ].
To identify the selection criteria of included trials, we only searched the methods sections. Therefore, it is possible that additional information about selection criteria could have been reported elsewhere in the paper.
We also only included English language papers and it is possible although unlikely that our findings may not be generalisable to non-English-language reports. We used an iterative method to describe the selection criteria of included trials and merged some categories together for ease of presentation.
We offer these suggestions in the spirit of starting and informing discussion surrounding the development of consensus on both clinically relevant domains of entry criteria for LBP trials, and the level of detail required for clarity in the description of how the criterion was operationalised.
This approach has worked well previously, where consensus processes have begun with some initial suggestions that are then assessed, scrutinised, and then refined [ 47 , 48 ]. We confined ourselves here to making suggestions for only commonly reported domains; although empirical research on what has happened in the past may or may not be the most desirable for informing consensus on what should be done in the future.
While consistency with what has gone before has value insofar as it facilitates between-trial comparisons, the questions surrounding domain choice and the level of detail that should be provided are principally clinical and in our view, would benefit from separate independent consideration within a Delphi process.
Our paper provides a useful basis for making comparisons with evaluations of nsLBP trials published after and after the publication of the NIH report [ 24 ].
It will also be important to determine whether there is any improvement in the reporting of selection criteria in future nsLBP trials based upon this paper and our suggested template. Inclusion and exclusion criteria in RCTs of nsLBP are diverse, and terms and descriptions used are inconsistent and often described ambiguously using over-arching terms.
The use of more consistent selection criteria and unambiguous reporting of these should improve population homogeneity between trials, facilitating comparisons and meta-analyses. We offer a template of criteria as a starting point that may be adapted, if required, depending on the intervention under investigation. Disability-adjusted life years DALYs for diseases and injuries in 21 regions, a systematic analysis for the global burden of disease study The global burden of low back pain: estimates from the global burden of disease study.
Ann Rheum Dis. Global, regional, and national disability-adjusted life years DALYs for diseases and injuries and healthy life expectancy HALE for countries, quantifying the epidemiological transition. Lidgren L. The bone and joint decade Bull World Health Organ. Chapter 4. European guidelines for the management of chronic nonspecific low back pain. Eur Spine J. Non-specific low back pain.
Woolf AD, Pfleger B. Burden of major musculoskeletal conditions. Chapter 3. European guidelines for the management of acute nonspecific low back pain in primary care. The individual and societal burden of chronic pain in Europe: the case for strategic prioritisation and action to improve knowledge and availability of appropriate care.
It is a common practice in clinical studies to clearly identify the inclusion and exclusion criteria for the research participants. The researcher uses a criteria that defines what participants should participate in the clinical trial. The researcher also specify a criteria to explain why other participants cannot participate in the research. The inclusion of the respondents is dependent on the factors that help meet the goals of the study. Respondent whose demographic, geographic or medical characteristics meet the requirement of the study are included in the study. Exclusion criteria of the study is dependent on any external characteristics of the respondents that can impact the study and make it incorrect or biased. For example the researcher is studying the prevalence of the major coronary diseases in adult males in the rural areas of the North Carolina.
Metrics details. Low back pain is a common health complaint resulting in substantial economic burden. Each year, upwards of 20 randomised controlled trials RCTs evaluating interventions for non-specific low back pain are published. Use of the term non-specific low back pain has been criticised on the grounds of encouraging heterogeneity and hampering interpretation of findings due to possible heterogeneous causes, challenging meta-analyses. We explored selection criteria used in trials of treatments for nsLBP. Study inclusion and exclusion criteria were extracted, thematically categorised, and then descriptive statistics were used to summarise the prevalence by emerging category. We included studies.
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Jump to navigation. Chapter 3: Defining the criteria for including studies and how they will be grouped for the synthesis. Cochrane Handbook for Systematic Reviews of Interventions version 6. Cochrane, Available from www.
Systematic reviews often exclude studies if they do not conform to specific study designs, are not written in English or within a certain time frame. As a researcher, you should be cautious of any bias you might introduce into the review by adding certain inclusion or exclusion criteria. For example: limiting to studies in English may miss important studies published in other languages. At this stage, the decisions are usually made using the titles and abstracts of the articles; those that are clearly irrelevant can be excluded.
Library Services. These are the boundaries that decide exactly what information you want to find in your literature search and allow you to decide which studies should be included or excluded in your results. Establishing your inclusion criteria should help you to turn your topic into a viable question.