1. Introduction: without a heading, provide a context and brief background for the study, giving only pertinent references in the literature review. State the nature of the research problem and its significance, major hypothesis or rationale, objectives or purpose of the study or observation.

2. Methods: should only include information available at the time the study plan or protocol was written; all information obtained during the course of the study belongs in the Results section. Provide sufficient detail to permit replication by others. Generally, it should contain the following:

a. Study Design: use phrases such as randomized or nonrandomized clinical trial, case-control or cross-sectional study, cohort study, case series or report, systematic review, meta-analysis, review, experimental study, historical manuscript. Additional modifiers may be used (e.g. retrospective, prospective, double-blinded). Reporting guidelines may be accessed as follows:


Type of Study



randomized controlled trials



systematic reviews and meta-analyses



observational studies in epidemiology



studies of diagnostic accuracy



case reports 


b. Setting: Multicenter, Primary, Secondary, Tertiary, Public or Private, Hospital, University Hospital or Clinical Practice

c. Subjects or Participants: Number of patients, selection procedures, eligibility and exclusion criteria, randomization procedure, masking. Do not use patients’ names, initials, or hospital numbers

For studies involving human subjects, indicate whether procedures were in accord with the Helsinki Declaration of 1975, and/or approved by the institutional review board (IRB) / Ethics Committee, and whether informed consent was secured. For animal subjects, indicate whether the institution’s or National Research Council’s guide for the care and use of laboratory animals were followed

d. Intervention or observation procedure(s) should be identified in sufficient detail to allow reproducibility of results. Identify methods, instruments and equipment with the manufacturers name and address in parenthesis, e.g. (Zeiss Corporation,San Leandro, CA, USA). Identify all drugs and chemicals including generic name(s), dosage(s) and route(s) of administration. Use milligram per kilogram dosages for pediatric patients. For metaanalyses or systematic reviews, cite methods used for locating, selecting, extracting and synthesizing data.

e. Main and secondary outcome measure(s)

f. Data and Statistical analysis: Describe statistical methods with enough detail to enable a knowledgeable reader with access to the original data to verify reported results. When possible, quantify findings and present them with appropriate indicators of measurement error or uncertainty (such as confidence intervals). Avoid relying solely on statistical hypothesis testing, such as the use of P values, which fail to convey important information about effect size. References for the study design and statistical methods should be to standard works when possible (with pages stated). Define statistical terms, abbreviations, and most symbols. Specify computer software and statistical packages used, eg MS Excel (Microsoft Corporation, Redmond, WA, USA) or Statistical Analysis System (SAS) version 6.12 (SAS Institute, Cary, NC, USA).

3. Results: Provide demographic data of the study population. Describe outcomes and measurements in a logical sequence with minimum discussion. Do not repeat in the text what can be summarized in tables and figures. When data are summarized in the Results section, give numeric results not only as derivatives (for example, percentages) but also as the absolute numbers (for example, fractions) from which the derivatives were calculated, and specify the statistical methods used to analyze them. Restrict tables and figures to those needed to explain the argument of the paper and to assess its support. Use graphs as an alternative to tables with many entries; do not duplicate data in graphs and tables. Avoid nontechnical uses of technical terms in statistics, such as “random” (which implies a randomizing device), “normal,”“significant,” “correlations,”and“sample.”Where scientifically appropriate, analyses of the data by variables such as age and sex should be included.

4. Discussion: Restrict to significant findings presented, emphasizing new and important aspects of the study. Avoid excessive generalization, undue speculation, digressions and theorizing. Elucidate but do not repeat data in the results section, discuss implications and limitations and relate these to other and contradictory literature. Incorporate conclusions supported by the data into the end of the discussion, without a separate heading. State new hypothesis when warranted, but clearly label them as such. Avoid making statements on economic benefits and costs unless the study includes economic data and analysis. Avoid claiming priority of content unless you provide the literature search protocol used. Include recommendations when appropriate.