METHODS: An MS Excel model was developed to assess the annual cost impact of OSA treatment with three stages: diagnostic, therapy initiation and follow-up. TM vs no TM use was compared from the NHS perspective. In the TM arm, 90% use was assumed as not all patients would be eligible. 650 new and 4.000 existing OSAH patients were included to be representative of a mid-size sleep clinic with 4 healthcare professionals (HCP). Costs were obtained as follows: PAP device, consumables and TM platform used NICE breakdown prices; HCP wages used PSSR book; and healthcare resource utilisation (HCRU) used NHS reference prices. TM use pathway assumptions: 1) diagnostic collection, return and PAP machine delivery were done by post; 2) higher adherence to PAP therapy and lower HCRU was assumed per the literature; 3) 40% of existing patients were on patient initiated follow-up protocol (PIFUP); 4) follow-up method was video or phone consultation with TM data; 5) for new patients, 1 visit was factored for adherent patients and 2 for non-adherent patients. No TM pathway assumptions: 1) 3 visits/annum was assumed; 2) 60% of existing patients on (PIFUP).