Table 1 CENT 2015 checklist: CONSORT 2010 checklist items with modifications or additions for individual or series of N-of-1 trials [15]

1a

Identification as a randomized trial in the title

1a

Identification as an “N-of-1 trial” in the title

For series: identification as “a series of N-of-1 trials” in the title

1b

Structured summary of trial design, methods, results, and conclusions (for specific guidance see CONSORT for abstracts)

1b

Background and objectives

2a

Scientific background and explanation of rationale

2b

Specific objectives or hypotheses

2c

Rationale for using N-of-1 approach

Trial design

3a

Description of trial design (such as parallel, factorial) including allocation ratio

3a

Describe trial design, planned number of periods, and duration of each period (including run-in and wash out, if applicable)

In addition for series: whether and how the design was individualized to each participant and explanation of the series design

3b

Important changes to methods after trial commencement (such as eligibility criteria), with reasons

Participant(s)

4a

Eligibility criteria for participants

4a

Diagnosis/disorder, diagnostic criteria, comorbid conditions, and concurrent therapies.

For series: same as CONSORT item 4a

4b

Settings and locations where the data were collected

4c

Whether the trial(s) represents a research study and if so, whether institutional ethics approval was sought

Interventions

5

The interventions for each group with sufficient details to allow replication, including how and when they were actually administered

5

The interventions for each period with sufficient details to allow replication, including how and when they were actually administered

Outcomes

6a

Completely defined pre-specified primary and secondary outcome measures, including how and when they were assessed

6a.1

Description and measurement properties (validity and reliability) of outcome assessment tools

6b

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

Sample size

7a

How sample size was determined

7b

When applicable, explanation of any interim analyses and stopping guidelines

Randomization

Sequence generation

8a

Method used to generate the random allocation sequence

8a

Whether the order of treatment periods was randomized, with rationale, and method used to generate allocation sequence

8b

Type of randomization; details of any restriction (such as blocking and block size)

8b

When applicable, type of randomization; details of any restrictions (e.g., pairs, blocking)

8c

Full, intended sequence of periods

Allocation concealment mechanism

9

Mechanism used to implement the random allocation sequence (such as sequentially numbered containers), describing any steps taken to conceal the sequence until interventions were assigned

Implementation

10

Who generated the random allocation sequence, who enrolled participants, and who assigned participants to interventions

Blinding

11a

If done, who was blinded after assignment to interventions (for example, participants, care providers, those assessing outcomes) and how

11b

If relevant, description of the similarity of interventions

Statistical methods

12a

Statistical methods used to compare groups for primary and secondary outcomes

12a

Methods used to summarize data and compare interventions for primary and secondary outcomes

12b

Methods for additional analyses, such as subgroup analyses and adjusted analyses

12b

For series: if done, methods of quantitative synthesis of individual trial data, including subgroup analyses, adjusted analyses, and how heterogeneity between participants was assessed, (for specific guidance on reporting syntheses of multiple trials, please consult the PRISMA Statement)

12c

Statistical methods used to account for carry-over effect, period effects, and intra-subject correlation

Participant flow (a diagram is strongly recommended)

13a

For each group, the numbers of participants who were randomly assigned, received intended treatment, and were analyzed for the primary outcome

13a.1

Number and sequence of periods completed and any changes from original plan with reasons

13a.2

For series: the number of participants who were enrolled, assigned to interventions, and analyzed for the primary outcome

13b

For each group, losses and exclusions after randomization, together with reasons

13c

For series: losses or exclusion of participants after treatment assignment, with reasons, and period in which this occurred, if applicable

Recruitment

14a

Dates defining the periods of recruitment and follow-up

14b

Why the trial ended or was stopped

14b

Whether any periods were stopped early and/or whether trial was stopped early, with reason(s)

Baseline data

15

A table showing baseline demographic and clinical characteristics for each group

Numbers analyzed

16

For each group, number of participants (denominator) included in each analysis and whether the analysis was by original assigned groups

16

For each intervention, number of periods analyzed

In addition for series: if quantitative synthesis was performed, number of trials for which data were synthesized

Outcomes and estimation

17a

For each primary and secondary outcome, results for each group, and the estimated effect size and its precision (such as 95 % confidence interval)

17a.1

For each primary and secondary outcome, results for each period; an accompanying figure displaying the trial data is recommended

17a.2

For each primary and secondary outcome, the estimated effect size and its precision (e.g., 95 % confidence interval)

In addition for series: if quantitative synthesis was performed, group estimates of effect and precision for each primary and secondary outcome

17b

For binary outcomes, presentation of both absolute and relative effect sizes is recommended

Ancillary analyses

18

Results of any other analyses performed, including subgroup analyses and adjusted analyses, distinguishing pre-specified from exploratory

18

Results of any other analyses performed, including assessment of carry-over effects, period effects, intra-subject correlation

In addition for series: if done, results of subgroup or sensitivity analyses

Harms

19

All important harms or unintended effects in each group (for specific guidance see CONSORT for harms)

19

All harms or unintended effects for each intervention (for specific guidance see CONSORT for harms)

Limitations

20

Trial limitations, addressing sources of potential bias, imprecision, and if relevant, multiplicity of analyses

Generalizability

21

Generalizability (external validity, applicability) of the trial findings

Interpretation

22

Interpretation consistent with results, balancing benefits and harms, and considering other relevant evidence

Registration

23

Registration number and name of trial registry

Protocol

24

Where the full trial protocol can be accessed, if available

Funding

25

Sources of funding and other support (such as supply of drugs), role of funders