Common Statistical Abbreviations that are always in italics Abbreviation Definition b, bi In regression and multiple regression analyses, estimated values of raw (unstandardized) regression coefficients In item response theory, the difficulty-severity parameter CI is usually found in the results section of a paper and provide the reader with an opportunity to draw conclusions about the importance of the size or strength of the results. CIs are expressed as X (A–B), where X is the observed statistic for example, a mean, A is the lower limit of the CI… For example, HR = 2 means that the experimental group has twice as big a risk of an event (often death, but could also be recurrence, remission, discharge or whatever) within a short period of time. Confidence interval, an interval estimate of a population parameter used in statistics; 101 (number) (in Roman numerals) Compound interest; Cosine integral (standard mathematical symbols "Ci" and "ci") Physics. Commonly used EBM and statistical abbreviations. For example, adjusted HR, 1.08; 95% CI, 0.85–1.36; P =.526 What are HR, CI and P, and what are they referring to? More formally, the CI around your sample statistic is calculated in such a way that it has a specified chance of surrounding (or “containing”) the value of the corresponding population parameter. I have a vague idea that they refer to Common Statistical Abbreviations and Symbols in APA (In italics) B. BMJ Best Practice » Evidence based medicine (EBM) toolkit » EBM Tools » Commonly used EBM and statistical abbreviations. Member States of the European Union (EU) and other countries have been assigned a two-letter country code, always written in capital letters, and often used as an abbreviation in statistical analyses, tables, figures or maps.. In texts, the term may also be abbreviated by ‘UE’. HR = Hazard Ratio. In German, the abbreviation is the same as in English and stands for ‘Europäische Union’. B. Common Statistical Abbreviations that are always in italics Abbreviation Definition b ... (as of a confidence interval, CI) wk Fixed effects weight wk* Random effects weight W Kendall’s coefficient of concordance and its estimate .