Dormuth 2009.

Methods	ITS
Participants	Canada, British Columbia (BC) PharmaCare Programme
Interventions	Ceiling + Fixed Ceiling + Co‐insurance
Outcomes	Cost
Notes	2 consecutive interventions are addressed Older patients with asthma or chronic obstructive pulmonary disease are addressed in the paper Same study as Dormuth 2006, Dormuth 2008 and Wang 2008b
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not applicable (ITS)
Allocation concealment (selection bias)	Unclear risk	Not applicable (ITS)
Baseline outcome measurement similarity	Unclear risk	Not applicable (ITS)
Baseline characteristics similarity	Unclear risk	Not applicable (ITS)
Protection against contamination	Unclear risk	Not applicable (ITS)
Intervention independent of other changes	High risk	The Ministry of Health increased its physician and hospital spending in response to the impact of policy changes
Shape of the intervention effect pre‐specified	Low risk	Point analysis is the point of intervention
Intervention unlikely to affect data collection	Low risk	Sources and methods were the same before and after the intervention
Incomplete outcome data (attrition bias) All outcomes	Low risk	No outcome data are missing
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcomes are objective
Selective reporting (reporting bias)	Low risk	All relevant outcomes in the Methods section are reported in the Results section
Other bias	Low risk	No other important bias is detected in the study