Study design

Description

Specific inclusion criteria

Controlled clinical trial

A trial in which participants were:

a) definitely assigned prospectively to 1 or 2 (or more) alternative forms of health care using a quasi‐random allocation method; or

b) possibly assigned prospectively to 1 or 2 (or more) alternative forms of health care using a process of random or quasi‐random allocation

Controlled before‐and‐after study

A study involving the inclusion of experimental and control groups by a non‐random process and inclusion of baseline period of assessment of main outcomes

1) Contemporaneous data collection for pre‐ and post‐intervention groups for intervention and control sites

2) Appropriate control site. Control site is comparable in terms of reimbursement system, level of care, setting of care, and academic status.

3) Minimum of 2 sites for each of the intervention and control groups

Interrupted time series study

A study demonstrating a change in trend for an outcome that is attributable to a particular intervention

1) Clearly defined point in time when the intervention occurred

2) Minimum of 3 data points both before and after the intervention occurred