Motheral 2004

Methods	Controlled ITS with monthly data points
Participants	Intervention: n=20,000 enrollees in Midwest employer plan, Control: random sample of members from commercial plans n=1.9 million member in 1021 different plans
Interventions	Effects of step therapy programs for PPI, NSAIDS, and SSRIs
Outcomes	Drug costs per member per month
Notes	Analyzed claims from Sep 1, 2001 to June 30, 003. A mailed survey component of the study did not meet the selection criteria of this review and therefore was not included or ROB for this component evaluated.
Risk of bias
Bias	Authors' judgement	Support for judgement
Incomplete outcome data (attrition bias) All outcomes	Low risk	Re:Drug cost data only; 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)	High risk	All 3 therapy class trends for control group not shown (just aggregated data)
Other bias	High risk	No baseline characteristics of patient population provided. Small sample sizes at drug class level.
Knowledge of allocated interventions adequately prevented during the study	Low risk	Drug cost data only: Outcomes are objective measures of health care utilization
Intervention independent of other changes	Low risk	Drug cost data only: Known and unknown changes in the environment are unlikely to be responsible for magnitude of effect size demonstrated.
The shape of intervention pre‐specified?	Low risk	Drug cost data only: 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	Drug use data only: Automated pharmacy claims pre and post intervention