2.8.2 Statistical analyses
SECONDARY, INTERACTION
Intervention effects were estimated from the model using methods described by Hussey and Hughes [Demographic variables were assessed cross-sectionally between arms only at baseline, while primary and secondary outcomes were assessed between arms cross-sectionally at baseline, at the 3-month follow-up and at the 8 month follow-up separately (i.e. no longitudinal analysis within clusters was performed), as described by Hemming As pre-specified in the protocol, we also analyzed model extensions: 1) random cluster by period effect, 2) random cluster by treatment effect, and 3) Interaction between intervention and time period. Details are described in the supplementary material. The model extensions were used for secondary analyses purpose. Each model extension makes implicit modifications to the assumptions about the correlation structure.STATA version 14 was used for all statistical analyses (StataCorp; College Station, TX). All results are reported as per the CONSORT extension for stepped wedge cluster randomized trial guidelines [