Glossary ======== **Axial coding**1: second level of coding in a grounded theory study that involves categorising, recategorising, and condensing first level codes by connecting categories and subcategories. **Blinding (masking)**: in an experimental study, refers to whether patients, clinicians providing an intervention, people assessing outcomes, and/or statisticians were aware or unaware of the group to which patients were assigned. In the design section of *Evidence-Based Nursing* abstracts of treatment studies, the study will be identified as *blinded*, with specification of who was blinded; *unblinded*, if all parties were aware of patients' group assignments; or *blinded (unclear)* if the authors did not report or provide us with an indication of who was aware or unaware of patients' group assignments. **Concealment of randomisation**: concealment of randomisation is specified in the design section of *Evidence-Based Nursing* abstracts of treatment studies as follows: *allocation concealed* (deemed to have taken adequate measures to conceal allocation to study group assignments from those responsible for assessing patients for entry in the trial [ie, central randomisation; numbered, opaque, sealed envelopes; sealed envelopes from a closed bag; numbered or coded bottles or containers; drugs prepared by the pharmacy; or other descriptions that contain elements convincing of concealment]); *allocation not concealed* (deemed to have not taken adequate measures to conceal allocation to study group assignments from those responsible for assessing patients for entry in the trial [ie, no concealment procedure was undertaken, sealed envelopes that were not opaque, or other descriptions that contained elements not convincing of concealment]); *unclear allocation concealment* (the authors did not report or provide a description of an allocation concealment approach that allowed for the classification as concealed or not concealed). **Concept map (schematic model)1**: representation of concepts in a figure, using boxes, arrows, and other symbols. **Confidence interval (CI)**: quantifies the uncertainty in measurement; usually reported as 95% CI, which is the range of values within which we can be 95% sure that the true value for the whole population lies. **Diagnostic (gold or criterion) standard**: the current best available measure of an outcome; used for assessing properties of a new diagnostic or screening test. The results from a new test are compared with the results from the diagnostic standard to assess the usefulness of the new test (ie, its sensitivity, specificity, and likelihood ratios). **Giorgi's method**2: an approach to the analysis of phenomenological data that involves 4 steps: (1) reading the text to get a sense of the whole; (2) dividing the text into meaning units; (3) transforming the language of the participants into disciplinary language (eg, nursing); and (4) synthesising the structure to describe its essence. **Grounded theory**1: an approach to collecting and analysing qualitative data with the aim of developing theories grounded in real world observations. **Intention to treat analysis (ITT)**: all patients are analysed in the groups to which they were randomised, even if they failed to complete the intervention or received the wrong intervention. **Likelihood ratio (for positive and negative results)**3: a way of summarising the findings of a study of a diagnostic test for use in clinical situations where there may be differences in the prevalence of the disease. The likelihood ratio for a positive test is the likelihood that a positive test result comes from a person that really does have the disorder rather than one that does not have the disorder (sensitivity/1-specificity). The likelihood ratio for a negative test is the likelihood that a negative test result comes from a person with the disorder rather than one without the disorder (1-sensitivity/specificity). **Linear analysis (regression)**: a statistical technique for determining the relation (prediction equation) between 2 continuous variables. **Multivariate analysis**4: analysis involving multiple independent or dependent variables. **Number needed to treat (NNT)**: number of patients who need to be treated to prevent 1 additional negative event (or to promote 1 additional positive event); this is calculated as 1/absolute risk reduction (rounded to the next whole number), accompanied by the 95% confidence interval. **Odds ratio (OR)**: describes the odds of a patient in the experimental group having an event divided by the odds of a patient in the control group having the event *or* the odds that a patient was exposed to a given risk factor divided by the odds that a control patient was exposed to the risk factor. **Open coding**1: first level of coding in a grounded theory study, consisting of basic descriptive coding of narrative content. **Phenomenology**1: an approach to inquiry that emphasises the complexity of human experience and the need to understand that experience holistically as it is actually lived. **Quasi-randomised study**: participants are not randomly allocated to groups, but some other form of allocation is used (eg, day of the week, month of birth). **Relative benefit increase (RBI)**: the proportional increase in the rates of good events between experimental and control participants; reported as a percentage (%). **Relative risk (RR)**: risk of adverse effects with a treatment relative to risk for those who do not receive treatment. **Relative risk reduction (RRR)**: the proportional reduction in outcome rates of bad events between experimental and control participants; it is reported as a percentage (%). **Sensitivity**5: a measure of a diagnostic test's ability to correctly detect a disorder when it is present in a sample of people. **Specificity**5: a measure of a diagnostic test's ability to correctly identify the absence of a disorder in a sample of people who do not have the disorder. **Stratified randomisation**6: used in trials to ensure that equal numbers of participants with a particular characteristic (eg, age) are allocated to each comparison group. **Weighted**: statistical analysis accounts for differences in certain important variables. ## References 1. Polit DF, Hungler BP. *Essentials of nursing research: methods, appraisal, and utilization*. Fourth edition. 2. Webb C. Information point: Colaizzi's framework for analysing qualitative data. J Clin Nurs 1999;8:576. [PubMed](http://ebn.bmj.com/lookup/external-ref?access_num=10786530&link_type=MED&atom=%2Febnurs%2F3%2F3%2F96.2.atom) [Web of Science](http://ebn.bmj.com/lookup/external-ref?access_num=000082883500013&link_type=ISI) 3. Streiner D, Geddes J. Some useful concepts and terms used in articles about diagnosis [editorial]. *Evidence-Based Mental Health* 1998 Feb;1:6–7. [FREE Full Text](http://ebn.bmj.com/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiRlVMTCI7czoxMToiam91cm5hbENvZGUiO3M6ODoiZWJtZW50YWwiO3M6NToicmVzaWQiO3M6NToiMS8xLzYiO3M6NDoiYXRvbSI7czoyMToiL2VibnVycy8zLzMvOTYuMi5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30=) 4. Dawson-Saunders B, Trapp RG. *Basic and clinical biostatistics*. Norwalk: Appleton and Lange, 1994. 5. Sackett DL, Haynes RB, Guyatt CH, et al. *Clinical epidemiology: basic science for clinical medicine*. Second edition. Boston: Little, Brown and Company, 1991. 6. Mulrow CD, Oxman AD, editors. *Cochrane Collaboration handbook* (updated September 1997). In: Cochrane Library, 4, 1997. Oxford: Update Software.