The guidelines manual

J1: Example of an evidence table for intervention studies

This table is also suitable for diagnostic studies that compare the effectiveness of two or more tests. This only applies if the test is included as part of a test-and-treat strategy – otherwise the evidence table for studies of diagnostic test accuracy (J2) should be used.

Title: (review question)

[1] Bibliographic reference: author(s), year, article title, journal, volume, pages.

[2] Study type: for example, randomised controlled trial, cohort or case-control studies.

[3] Number of patients: total number of patients included in the study, including number of patients in each arm, with inclusion and exclusion criteria. Also record the numbers of patients who started and completed the study.

[4] Patient characteristics: characteristics relevant to the area of interest: age, sex, ethnic origin, comorbidity, disease status, community- or hospital-based.

[5] Intervention: treatment, procedure or test studied. If important for the study, specify duration of treatment. For diagnostic studies the intervention is the diagnostic test plus associated treatment studied.

[6] Comparison: placebo or alternative treatment. For diagnostic studies, comparison of the test is with another test and treatment strategy.

[7] Length of follow-up: the length of time that patients take part in the study for, from first staging treatment until either a pre-specified end-point (for example, death, specified length of disease-free remission) or the end of the data-gathering phase is reached. If the study is stopped earlier than originally planned for any reason, this should be noted here.

[8] Outcome measures: list all outcome measures defined in the review protocol, including associated harms. For studies with a diagnostic component there will be two interventions to consider – the diagnostic test used and the associated treatment. Use a separate line for each outcome.

Effect size: for example, raw data from the study that allow analyses such as absolute risk reduction and relative risk (reduction), number needed to treat, number needed to harm, odds ratios, as required. Give confidence intervals whenever possible.

[9] Source of funding: government funding (for example, NHS), voluntary/charity (for example, Wellcome Trust), pharmaceutical company; and the role of funding organisations.

[10] Additional comments: additional characteristics and/or interpretations of the studies that the reviewer wishes to record. These might include important flaws in the study not identifiable from other data in the table, and additional questions or issues that will need to be considered but do not figure in the results tables in the study.

J2: Example of an evidence table for studies of diagnostic test accuracy

Title: (review question)

[1] Bibliographic reference: author(s), year, article title, journal, volume, pages.

[2] Study type: for example, cross-sectional, cohort or case–control studies.

[3] Study quality: note particular strengths and weaknesses.

[4] Number of patients: total number of patients included in the study, with inclusion and exclusion criteria.

[5] Prevalence: proportion of people with the disease in the population at risk.

[6] Patient characteristics: characteristics relevant to the area of interest: age, sex, ethnic origin, comorbidity, disease status, community- or hospital-based.

[7] Type of test: description of the diagnostic test used in the study. Specify the test threshold where applicable.

[8] Reference standard: used as a measure of outcome. Specify if it is a 'gold standard' or 'current best practice'.

[9] Sensitivity: proportion of individuals classified as positive by the gold (or reference) standard who are correctly identified by the study test.
Specificity: proportion of individuals classified as negative by the gold (or reference) standard who are correctly identified by the study test.

Raw data for 2 x 2 table: study data collected from tests to calculate sensitivity, specificity, and positive and negative predictive values (see example table below)

[10] Positive predictive value: proportion of individuals with a positive test result who actually have the disease.
Negative predictive value: proportion of individuals with a negative test result who do not have the disease.

[11] Source of funding: government funding (for example, NHS), voluntary/charity (for example, Wellcome Trust), pharmaceutical company; and the role of funding organisations.

[12] Additional comments: additional characteristics and/or interpretations of the studies that the reviewer wishes to record. These might include important flaws in the study not identifiable from other data in the table, and additional questions or issues that will need to be considered but do not figure in the results tables in the study (for example, if a test is one of a sequence of tests; if its utility was determined).

J3: Example of an evidence table for prognostic studies

Title: (review question)

[1] Bibliographic reference: author(s), year, article title, journal, volume, pages.

[2] Study type: for example, cohort, nested cohort, case series.

[3] Study quality: note particular strengths and weaknesses.

[4] Number of patients: total number of patients included in the study, including number and proportion of patients with prognostic factor(s), with inclusion and exclusion criteria. Also record numbers of patients who started and completed the study.

[5] Patient characteristics: characteristics relevant to the area of interest: age, sex, ethnic origin, comorbidity, disease status, community- or hospital-based. Include method used to select participants.

[6] Prognostic factor(s): include details of method of measurement.

[7] Length of follow-up: the length of time that patients take part in the study for, from entry until either a pre-specified end-point (for example, death, specified length of disease-free remission) or the end of the data-gathering phase is reached. If the study is stopped earlier than originally planned for any reason, this should be noted here.

[8] Outcome measures: all outcome measures should be listed, with each on a separate line.

[9] Results: relative risk or hazard associated with the prognostic factor of interest; absolute risk of event in baseline group; time-to-event analysis.

[10] Source of funding: government funding (for example, NHS), voluntary/charity (for example, Wellcome Trust), pharmaceutical company; and the role of funding organisations.

[11] Additional comments: additional characteristics and/or interpretations of the studies that the reviewer wishes to record. These might include important flaws in the study not identifiable from other data in the table, and additional questions or issues that will need to be considered but do not figure in the results tables in the study.

J4: Example of an evidence table for qualitative studies

Title: (review question)

[1] Bibliographic reference: author(s), year, article title, journal, volume, pages.

[2] Research question: what was/were the research question(s)?

[3] Theoretical approach: what theoretical approach (for example, grounded theory, interpretive phenomenological analysis) does the study take (if specified)?

[4] Data collection: how were the data collected? Give details of:

[5] Method and process of analysis: what methods were used to analyse the data (for example, constant comparative method)?

[6] Population and sample collection: what population was the sample recruited from? Include the following information:

[7] Key themes: list all relevant to this review (with illustrative quotes if available).

[8] Source of funding: government funding (for example, NHS), voluntary/charity (for example, Wellcome Trust), pharmaceutical company; and the role of funding organisations.

[9] Limitations: both those identified by the author(s) and those identified by the reviewer.

[10] Evidence gap and/or recommendations for future research.