Guidance for reporting a description of active and placebo/sham interventions
This advice extends item 5 of the CONSORT advice for reporting interventions in trials, and is based on the TIDieR-placebo reporting guideline Read more
The following information was originally published here.
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1. Brief name
Provide a name or a phrase that describes both the active and the placebo/sham intervention.
Brand-name, expensive interventions have been shown in some studies to have greater effects. The name also enables easy identification of the placebo or sham intervention in the report. Abbreviations or acronyms should be explained in full or short descriptive statements provided.
Example/s:
0.9% normal saline.
…the enhanced group’s active treatment was referred to as Singulair.
2. Why
Describe any rationale, theory, or goal of the elements essential to both the active and placebo/sham intervention.
The rationale for the placebo or sham chosen will usually (but not always) be to control for certain components of the active intervention. These components should be specified so that readers can appraise the extent to which this aim was achieved.
Example/s:
Because brand names are associated with increased perceived potency.
To control for therapist contact and support, expectations, homework tasks, etc, RT [Relaxation Techniques] participants were taught a series of relaxation techniques….
3. What (materials)
Describe any physical or informational materials used in the intervention, including those provided to participants or used in intervention delivery or in training of intervention providers.
Provide information on where the materials can be accessed (for example, online appendix, URL).
Example/s:
We used transcutaneous electrical nerve stimulation (TENS) equipment…For sham, instead of DD [Dense Disperse], a 40Hz adjustable (ADJ) wave was used.
…placebo (consisting of calcium phosphate, starch, cellulose, and magnesium stearate)…the placebo tablets were the same size and shape as the penicillin tablets, the tablets were not identical owing to the cost implications of overencapsulation (the placebo tablets were unmarked, and the penicillin tablets were marked).
4. What (procedures)
Describe each of the procedures, activities, and/or processes used in the active and placebo/sham interventions, including any enabling or support activities.
Beyond describing standard procedures, reporting of more subtle procedures (such as nonverbal cues) and context can influence outcomes.
Example/s:
Participants were encouraged to discuss their health anxiety and helpful ways of coping with it and to provide support to others randomised to the control group. The discussion forum was monitored by a clinical psychologist on a daily basis to ensure that discussions were conducted in a respectful manner
The placebo group received a sham Kinesio Tape application, consisting of a single I-strip of the same tape applied transversely immediately above the point of maximum lumbar pain.
5. Who provided
For each category of active and placebo/sham intervention provider (such as psychologist, nursing assistant), describe their expertise, background, and any specific training given.
Example/s:
Four physical therapists, all with a minimum of five years of clinical experience in outpatient orthopaedic settings.
Six acupuncturists trained in traditional Chinese medicine, licensed by the Texas State Board of Medical Examiners, were recruited through the American College of Acupuncture & Oriental Medicine (ACAOM). To ensure uniformity, all were Chinese, male, and had at least two years of clinical experience.
6. How
Describe the modes of delivery (such as face to face or by some other mechanism, such as internet or telephone) of the placebo/sham intervention and whether it was provided individually or in a group.
Example/s:
Three of the sessions were face-to-face, where the patient came into the hospital to meet with the therapist. The other five sessions were completed by telephone to increase the likelihood of attendance and reduce the stress of travel for participants.
Intervention was delivered over the phone.
7. Where
Describe the type(s) of locations(s) and settings where the active and placebo/sham intervention occurred, including any necessary infrastructure or relevant features.
Both geographic location and features of the location (setting) can be important.
Example/s:
...32 hospital sites in the UK
Cadet Physical Therapy Clinic at the United States Military Academy or Keller Army Community Hospital at West Point, NY.
8. When and how much
Describe the number of times the active and placebo/sham intervention was delivered and over what period of time, including the number of sessions, their schedule, and their duration, intensity, or dose.
If relevant, include the duration of the pre- and postrandomisation consultations. Reporting the pre- and postintervention consultation details is especially important in cases in which practitioners are not blinded after randomisation (as is often the case in sham surgery trials). In the prerandomisation consultation, equal time and the same ‘quality of care’ might be spent describing the placebo compared with the experimental active intervention. One of our surgical trial experts (JLR) highlighted his experience of the ease with which postsurgical consultations or clinical contact with other treating health professionals can advertently or inadvertently unblind the patient and subsequently affect some clinical outcomes. For example, a recovery nurse might read an operation note (and learn which group the patient was in) and, not knowing the patient was in a trial, reveal to the patient which intervention they received.
Example/s:
…a loading dose of 1 g of tranexamic acid infused over 10 min, followed by intravenous infusion of …matching placebo (0·9% saline)…over 8 h.
For sham, instead of dense disperse wave, a 40Hz adjustable wave was used. Voltage was increased until the patient could feel it and then immediately turned off. Patients rested for 20’ with the needles retained, but without TENS stimulation.
9. Tailoring
If the active and placebo/sham intervention was planned to be personalised, titrated, or adapted, then describe what, why, when, and how.
Example/s:
Participants were asked if the tape was limiting lumbar movement and, if so, the tape was reapplied so that they had unrestricted range of motion
Patients were allowed to receive placebo beyond radiographic progression as long as they continued to have clinical benefit.
10. Modifications
If the active and placebo/sham intervention was modified during the course of the study, describe the changes (what, why, when, and how).
Example/s:
In some cases, the face-to-face were replaced with phone sessions if needed.
…the protocol was amended to require a time-out before the beginning of surgery [sham neurosurgery] on each side of the brain, with the coordinates confirmed by the surgeon and documented in writing by a study coordinator or other surgical team member before penetration of the brain.
11. How well (planned)
If active and placebo/sham intervention adherence or fidelity was assessed, describe how and by whom, and if any strategies were used to maintain or improve fidelity, describe them.
Planning to measure adherence to active as well as placebo/sham intervention could help detect whether an adverse event or unblinding may have contributed to change in adherence.
Example/s:
We also requested that patients complete a diary card on which the number of pills [placebo and active intervention] taken every day was recorded
[Sham exercise] Sessions were recorded in a logbook to ensure compliance.
12. How well (actual)
If the active and placebo/sham intervention adherence or fidelity was assessed, describe the extent to which they were delivered as planned.
Example/s:
Four patients did not receive the allocated injection (1 in the placebo group and 3 in the corticosteroid group) due to nonattendance (n = 2; 1%) or alternative medical advice (n = 2; 1%)
…the proportion of patients who reported taking at least 75% of the tablets was similar in the two groups (79% in the penicillin group and 78% in the placebo group).
13. Measuring the success of blinding
Was blinding measured, and if so, how, and what were the results of such measurement?
Failure to demonstrate the success of blinding does not imply that the trial is invalid or lower quality. However, it can be useful to know whether blinding was successful in cases where it was measured.
Example/s:
As the James’ blinding indices were >0.5 and Bang’s blinding indices did not approach 1 or −1, participants were considered to have been blinded successfully on average.
Treatment allocation was correctly guessed by the outcome assessor in 53% (20/38) of cases receiving the placebo injection only, 39% (16/41) of cases receiving the placebo injection plus physiotherapy, 44% (18/41) of cases receiving the corticosteroid injection only, and 39% (15/38) of cases receiving the corticosteroid injection plus physiotherapy.
To acknowledge this checklist in your methods, please state "We used the TIDieR checklist when writing our report [citation]". Then cite this checklist as Howick J, Webster RK, Rees J, Turner R, Macdonald H, 1. Price A, Evers WMA, Bishop FL, Collins GS, Bokelmann K, Hopewell S, Knottnerus A, Lamb S, Madigan C, Napadow V, Papanikitas A, Hoffmann T. TIDieR-Placebo: a guide and checklist for reporting placebo and sham controls. PLoS Med. 2020;17(9):e1003294..
The TIDIER-Placebo checklist is distributed under the terms of the Creative Commons Attribution License CC-BY