e- discussion on consort 2010 statement

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Dear members, we

will continue our discussion with checklists on methods part of the trial. This part of checklist mainly covers

reporting on trial design, inclusion & exclusion criteria, interventions,

outcomes, sample size and statistical methods.

Methods

Trial

Design

Item 3a - Description of trial design (such as parallel, factorial) including

allocation ratio.

The word "design"

is often used to refer to all aspects of how a trial is set up, such as

multicenter, stratified, randomized, double-blind, placebo-controlled,

parallel-group study

The CONSORT

statement focuses mainly on trials with participants individually randomized to

one of two "parallel" groups. Although in this version other different types of

randomized trials are also included.

Changes

to trial design

Item 3b - Important changes to methods after trial commencement (such as

eligibility criteria), with reasons.

There may be

deviations from the original protocol, as it is impossible to predict every

possible change in circumstances during the course of a trial. Such changes

could be due to external information becoming available from other studies, or

internal financial difficulties, or could be due to a disappointing recruitment

rate.

Participants

Item 4a - Eligibility criteria for participants.

A comprehensive

description of the eligibility criteria used to select the trial participants

is needed.

Item

4b.

Settings and locations where the data were collected

Recruited from

primary, secondary, or tertiary health care or from the community?

Healthcare

institutions vary greatly in their organisation, experience, and resources and

the baseline risk for the condition under investigation.

Author should

report the location site, including the country, city if applicable, and

immediate environment (for example, community, office practice, hospital

clinic, or inpatient unit)

Interventions

Item

5 -

The interventions for each group with sufficient details to allow replication,

including how and when they were actually administered.

Authors should

describe how to administer the intervention that was evaluated in the trial.

Here information

should include:

·

Drug

name

·

Dose,

method of administration (such as oral, intravenous)

·

Timing

and duration of administration,

·

Conditions

under which interventions are withheld.

If the control

group is to receive, it is important to describe thoroughly what that

constitutes.

Outcomes

Item 6a - Completely defined pre-specified primary and secondary outcome

measures, including how and when they were assessed.

·

The primary outcome: Pre-specified outcome

considered to be of greatest importance.

·

The Secondary outcomes: Unanticipated or unintended

effects of the intervention.

Item

6b. Any

changes to trial outcomes after the trial commenced, with reasons:

There are many reasons for deviations from the initial

study protocol. Authors should report and explain all major changes to the

protocol, including unplanned changes to eligibility criteria, interventions,

examinations, data collection, methods of analysis, and outcomes.

Sample size

7. How sample size was determined?

·

Should be carefully

planned, with a balance between medical and statistical considerations.

·

A study should be

large enough to have a high probability (power) of detecting as statistically

significant difference

·

Large samples are

necessary to detect small differences.

Elements of the

sample size calculation are:

(1) The estimated outcomes in each group (which

implies the clinically important target difference between the intervention

groups

(2) The α (type I)

error level;

(3) The statistical power (or the β (type II) error

level); and

(4) For continuous outcomes, the standard deviation of

the measurements.

Interim

analyses and stopping guidelines

Item

7b -

When applicable, explanation of any interim analyses and stopping guidelines.

If an intervention is working particularly well

or badly, a long period study may need to be ended early for ethical reasons.

This concern can be addressed by examining results as the data accumulate,

preferably by an independent data monitoring committee. However, performing

multiple statistical examinations of accumulating data without appropriate

correction can lead to erroneous results and interpretations.

In such condition, sequential statistical

methods are used to compare the data at each interim analysis, and a P value

less than the critical value specified by the group sequential method indicates

statistical significance.

Randomization

Item 8a.

Method used to generate the random allocation sequence.

Participants should be assigned to comparison

groups in the trial on the basis of a chance (random) process characterized by

unpredictability. Authors should provide sufficient information that the reader

can assess the methods used to generate the random allocation sequence and the

likelihood of bias in group assignment.

Item 8b. Type of randomization; details of any

restriction (such as blocking and block size).

Which

type of randomization? : Simple,

Restricted, Blocked or Stratified.

Item 9. Mechanism used to implement the random

allocation sequence.

Author

should report the actual steps taken to ensure allocation concealment.

E.g." The doxycycline and placebo

were in capsule form and identical in appearance. They were prepacked in

bottles and consecutively numbered for each participant according to the

randomization schedule.

Item10. Who generated the

allocation sequence, who enrolled participants, and who assigned participants

to interventions?

In addition to knowing the

methods used, it is also important to understand how the persons were separately

deputed for different steps of randomization (sequence generation, allocation

concealment, and implementation) were implemented. Thus, if someone is involved

in the sequence generation or allocation concealment steps, ideally they should

not be involved in the implementation step.

Item 11a : If done, who was

blinded after assignment to interventions (for example, participants, care

providers, those assessing outcomes) and how?

Blinding is an important

safeguard against bias, particularly when assessing subjective outcomes. Author

has to report: which type of blinding and how it was done?

Item 11b: If relevant,

description of the similarity of interventions:

Authors should state the

similarity of the characteristics of the interventions (such as appearance,

taste, smell, and method of administration).There should not be any difference

in the experimental or control intervention.

Statistical methods

12a

- Statistical methods used to compare groups for primary and secondary outcomes.

Author should follow this principle for statistical analysis "Describe

statistical methods with enough detail to enable a knowledgeable reader with

access to the original data to verify the reported results".

Statistical methods should be provided for analysis of both primary as

well as secondary outcomes.

Authors should accompany statistical method with a confidence interval

(95%) for the estimated effect, which indicates a central range of uncertainty

for the true treatment effect.

The P value represents the probability that the observed data could have

arisen by chance when the interventions did not truly differ (p<0.05 is

usually considered as significant value).

Contd………….