Comparison of dispensing rates in subgroup analyses
REGRESSION
Some pre-defined subgroup analyses did interact with the treatment effect, with evidence of increased dispensing rates in the intervention arm among practices located in areas with a higher level of deprivation (P=0.004), practices with more than one site (P<0.001), and practices with a higher proportion of prescribing nursing staff (P<0.001) (Subgroup analyses for dispensing outcomeCCG=clinical commissioning group; CI=confidence interval.All subgroup analyses were pre-specified in statistical analysis plan,Dichotomised on basis of median for continuous subgroups.Rates taken from random effects Poisson regression, incorporating CCG as random effect.Random effects Poisson regression, adjusting for baseline dispensing rate and incorporating CCG as random effect.Taken from likelihood ratio test comparing random effects Poisson models with/without interaction term included, treating subgroup of interest as continuous variable where possible.Taken from practice follow-up questionnaire.Index of deprivation ranks every neighbourhood in England from 1 (most deprived area) to 32 844 (least deprived area).