Table 13.2.a: List of study design features (studies with allocation to interventions at the individual level)

 

RCT

Q-RCT

NRCT

CBA

PCS

RCS

HCT

NCC

CC

XS

BA

CR/CS

Was there a comparison:

 

 

 

 

 

 

 

 

 

 

 

 

 Between two or more groups of participants receiving different interventions?

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

N

N

 Within the same group of participants over time?

P

P

N

Y

N

N

N

N

N

N

Y

N

Were participants allocated to groups by:

 

 

 

 

 

 

 

 

 

 

 

 

 Concealed randomization?

Y

N

N

N

N

N

N

N

N

N

na

na

 Quasi-randomization?

N

Y

N

N

N

N

N

N

N

N

na

na

 By other action of researchers?

N

N

Y

P

N

N

N

N

N

N

na

na

 Time differences?

N

N

N

N

N

N

Y

N

N

N

na

na

 Location differences?

N

N

P

P

P

P

P

na

na

na

na

na

 Treatment decisions?

N

N

N

P

P

P

N

N

N

P

na

na

 Participants' preferences?

N

N

N

P

P

P

N

N

N

P

na

na

 On the basis of outcome?

N

N

N

N

N

N

N

Y

Y

P

na

na

 Some other process? (specify)

 

 

 

 

 

 

 

 

 

 

 

 

Which parts of the study were prospective:

 

 

 

 

 

 

 

 

 

 

 

 

 Identification of participants?

Y

Y

Y

P

Y

N

P*

Y

N

N

P

P

 Assessment of baseline and allocation to intervention?

Y

Y

Y

P

Y

N

P*

Y

N

N

na

na

 Assessment of outcomes?

Y

Y

Y

P

Y

P

P

Y

N

N

P

P

 Generation of hypotheses?

Y

Y

Y

Y

Y

Y

Y

Y

P

P

P

na

On what variables was comparability between groups assessed:

 

 

 

 

 

 

 

 

 

 

 

 

  Potential confounders?

P

P

P

P

P

P

P

P

P

P

N

na

  Baseline assessment of outcome variables?

P

P

P

Y

P

P

P

N

N

N

N

na

 

Y=Yes; P=Possibly; P*=Possible for one group only; N=No; na=not applicable. NB:. Note that ‘possibly’ is used in the table to indicate cells where either ‘Y’ or ‘N’ may be the case. It should not be used as a response option when applying the checklist; if uncertain, the response should be ‘can’t tell’ (see Box 13.4.a). 

RCT=Randomized controlled trial; Q-RCT=Quasi-randomized controlled trial; NRCT=Non-randomized controlled trial; CBA=Controlled before-and-after study; PCS=Prospective cohort study; RCS=Retrospective cohort study; HCT=Historically controlled trial; NCC=Nested case-control study; CC=Case-control study; XS=Cross-sectional study; BA=Before-and-after comparison; CR/CS=Case report/Case series.