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

 

ClRCT

ClQ-RCT

ClNRT

CITS

CChBA

ITS

ChBA

EcoXS

Was there a comparison:

 

 

 

 

 

 

 

 

 Between two or more groups of clusters receiving different interventions?

Y

Y

Y

Y

Y

N

N

Y

 Within the same group of clusters over time?

P

P

N

Y

N

Y

Y

N

Were clusters allocated to groups by:

 

 

 

 

 

 

 

 

 Concealed randomization?

Y

N

N

N

N

N

N

N

 Quasi-randomization?

N

Y

N

N

N

N

N

N

 By other action of researchers?

N

N

Y

P

P

N

N

N

 Time differences?

N

N

N

Y

Y

Y

Y

N

 Location differences?

N

N

P

P

P

N

N

P

 Policy/public health decisions?

Na

na

P

P

P

P

na

na

 Cluster preferences?

Na

na

P

P

P

P

na

na

 Some other process? (specify)

 

 

 

 

 

 

 

 

Which parts of the study were prospective:

 

 

 

 

 

 

 

 

 Identification of participating clusters?

Y

Y

Y

P

P

P

P

N

 Assessment of baseline and allocation to intervention?

Y

Y

Y

P

P

P

P

N

 Assessment of outcomes?

Y

Y

Y

P

P

P

P

N

 Generation of hypotheses?

Y

Y

Y

Y

Y

Y

Y

P

On what variables was comparability between groups assessed:

 

 

 

 

 

 

 

 

  Potential confounders?

P

P

P

P

P

P

P

P

  Baseline assessment of outcome variables?

P

P

P

Y

Y

Y

Y

N

Note that ‘cluster’ refers to an entity (e.g. an organization), not necessarily to a group of participants; ‘group’ refers to one or more clusters; see Box 13.4.a.

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, ‘can’t tell’ should be used (see Box 13.4.a).

Y=Yes; P=Possibly; P*=Possible for one group only; N=No; NR=Not required. ClRCT=Cluster randomized controlled trial; ClQ-RCT=Cluster quasi-randomized controlled trial; ClNRT=Cluster non-randomized controlled trial; CITS=Controlled interrupted time series (Shadish 2002); CChBA=Controlled cohort before-and-after study (Shadish 2002); ITS=Interrupted time series; ChBA=Cohort before and after study (Shadish 2002); EcoXS=Ecological cross-sectional study.