Fischer 2007

Methods	Controlled ITS with quarterly data points
Participants	Intervention: n=19 state Medicaid programs with PA for ARBs before 3rd quarter of 2004, Control: n=18 states without PA
Interventions	PA policies on the use of ARBS
Outcomes	Drug use, drug costs
Notes	States very as to how strictly the policy was implemented. As well some states have rebate arrangements. These differences explain some of the variability.
Risk of bias
Bias	Authors' judgement	Support for judgement
Incomplete outcome data (attrition bias) All outcomes	Low risk	Any undocumented difference in the proportion of missing data in the administrative datasets pre‐ and post‐intervention is unlikely to overturn study results.
Selective reporting (reporting bias)	Low risk	All outcomes listed in the methods section are reported in the results section
Other bias	Low risk	No evidence of other risk of bias including seasonality.
Knowledge of allocated interventions adequately prevented during the study	Low risk	Outcomes are objective measures of healthcare utilization
Intervention independent of other changes	Unclear risk	Total prescribing for hypertension in Medicaid more than doubled from 1996 to 2005, from about eight million prescriptions per quarter to more than 17 million.
The shape of intervention pre‐specified?	Low risk	The point of analysis is the point of intervention; ie, the date the policy intervention was implemented was used to delineate pre and post policy time periods with adequate data points to capture the shape of the pattern of intervention effect over time
Intervention unlikely to affect data collection?	Low risk	Sources and methods of data collection were the same before and after the intervention.