Kephart 2005

Methods	Controlled ITS with monthly data points
Participants	Nova Scotia Seniors’ Pharmacare Program: ≥ 65 years N=21,864 received at least one prescription for inhaled repiratory drugs; n=5129 with one prescription for wet nebulization therapy, 108,160 beneficiaries from 1998–1999, 103,400 from 1999–2000, and 95,550 from 2000–2001
Interventions	PA policy requiring specific criteria to be met for utilization of wet nebulizer therapy
Outcomes	Drug use, health services utilization
Notes	Study period April 1998–February 2002, 6 month transition (policy intervention) period
Risk of bias
Bias	Authors' judgement	Support for judgement
Incomplete outcome data (attrition bias) All outcomes	Low risk	Rates were adjusted for loss to follow up due to death, migration, and dropping out of the program.
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	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