Table 3.

Content of 2-week phone call measures

Concept	Measurement method	Details
Treatment compliance	- number of times visited trial physiotherapist so far - extent of compliance with prescribed exercises	5 point Likert scale
Change in knee symptoms	- any change - specific change	yes, no 5 point Likert scale
Knee pain intensity		11 point numerical rating scale (NRS)
Credibility of interventions	- confidence in received treatment - logic of received treatment Adapted from [60]	5 point Likert scale
Experiences and expectations	- treatment met expectations - expected improvement with treatment	5 point Likert scale 11 point NRS
Treatment preference	- want to change treatment receiving	yes, no, not sure