ObjectivesTo compare the quality of communication in out-of-hours (OOH) telephone triage conducted by general practitioners (GPs), nurses using a computerised decision support system and physicians with different medical specialities, and to explore the association between communication quality and efficiency, length of call and the accuracy of telephone triage.DesignNatural quasi-experimental cross-sectional study.SettingTwo Danish OOH services using different telephone triage models: a GP cooperative and the medical helpline 1813.Participants1294 audio-recorded randomly selected OOH telephone triage calls from 2016 conducted by GPs (n=423), nurses using CDSS (n=430) and physicians with different medical specialities (n=441).Main outcome measuresTwenty-four physicians assessed the calls. The panel used a validated assessment tool (Assessment of Quality in Telephone Triage, AQTT) to measure nine aspects of communication, overall perceived communication quality, efficiency and length of call.ResultsThe risk ofpoorquality was significantly higher in calls triaged by GPs compared with calls triaged by nurses regarding ‘allowing the caller to describe the situation’ (GP: 13.5% nurse: 9.8%), ‘mastering questioning techniques’ (GP: 27.4% nurse: 21.1%), ‘summarising’ (GP: 33.0% nurse: 21.0%) and ‘paying attention to caller’s experience’ (GP: 25.7% nurse: 17.0%). The risk ofpoorquality was significantly higher in calls triaged by physicians compared with calls triaged by GPs in five out of nine items. GP calls were significantly shorter (2 min 57 s) than nurse calls (4 min 44 s) and physician calls (4 min 1 s). Undertriaged calls were rated lower than optimally triaged calls for overall quality of communication (p<0.001) and all specific items.ConclusionsCompared with telephone triage by GPs, the communication quality was higher in calls triaged by nurses and lower in calls triaged by physicians with different medical specialities. However, calls triaged by nurses and physicians were longer and perceived less efficient. Quality of communication was associated with accurate triage.