Hartung 2004

Methods	Controlled ITS with monthly data points
Participants	Intervention group Medicaid managed care organization (MCO): 1999: n=74,866 patients, 200: n=91,816; control group (fee for service): 1999:n=110,076, 2000: n=153,784. Control group: members of the same MCO with past NSAID or COX2 use and continuous enrollment
Interventions	PA policy for celecoxib
Outcomes	Drug use, health servics utilization, drug costs
Notes	No notification to physicians and payments as to when the policy implemented.
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)	Unclear risk	All outcomes listed in the methods section are reported in the results sections
Other bias	Unclear risk	Control population consisted of patients who were generally older and likely to be more severely ill which would tend to increase drug use
Knowledge of allocated interventions adequately prevented during the study	Low risk	Data objective: All Medicaid claims for patients in CareOregon and in a Medicaid fee‐for‐service program were reviewed.
Intervention independent of other changes	Low risk	Known and unknown changes in the environment are unlikely to be responsible for sudden change and magnitude of effect size
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