Table 1 Variables included in the stochastic actor-oriented models, their definitions, and corresponding hypotheses

Actor effects

Seeker-highly engaged: The tendency of highly engaged staff to make or maintain ties with others.

Source-highly engaged: The tendency of staff to make or maintain ties with highly engaged staff. Positive changes support hypothesis H1.

Seeker x source-highly engaged: The tendency of highly engaged staff to make or maintain ties with each other. Positive changes support hypothesis H3.

Seeker x source-highly engaged reciprocity: The tendency of highly engaged staff to reciprocate each other’s ties. Positive changes support hypothesis H4.

Seeker-baseline EBP score: The tendency of the staff with higher EBP implementation score to make or maintain ties with others

Source-baseline EBP score: The tendency of staff to make or maintain ties with others with higher baseline EBP implementation score. Positive changes support hypothesis H2.

Seeker-EBP score change: The tendency of the staff with larger improvement in EBP implementation score to make or maintain ties with others.

Source-EBP score change: The tendency of staff to make or maintain ties with others with larger improvement in EBP implementation score. Positive changes support hypothesis H2.

Dyadic effects

Inter-divisional: The tendency of staff to seek information form staff from other divisions. Positive changes supported hypothesis H5.

Structural effects

Reciprocity: The number of reciprocated ties for each actor.

Transitive triplets: The number of transitive patterns in actor A’s connections, which is the number of B,C pairs which actor A is connected to both and also B is connected to C.

3-cycles: A generalized measure of reciprocity. The number of 3-cycles in actor A’s connections, which is the number of B,C pairs which A connects to B, B connects to C, and C connects to A. A negative value for 3-cycle effect along with a positive transitivity effect is an indicator of tendency towards forming local hierarchy.

Preferential in-degree centrality: sum of the in-degrees to actors to whom actor A is connected (the centrality of alter effect), which shows the tendency of network towards centralization.