Smeele P, et al. - Given that Primary Care Plus (PC+) facilities have been founded in the city of Maastricht, the Netherlands, with a goal to achieve substitution of hospital care with primary care and thus attenuate costs, researchers assessed referral patterns per specialty, specialist and diagnosis group, as input for deliberations to optimise substitution. For eight participating specialties, they analyzed prospectively gathered referral data post-PC+ consultations between November 2014 and March 2016. Of 4536 patients seen in PC+, those referred back to the general practitioner were 3132 (69.0%), whereas those referred to secondary care were 1275 (28.1%). Following PC+ consultation, there existed wide variations in referral numbers to secondary care between specialties (from 8.6% (gynaecology) to 43.8% (orthopaedic surgery)), specialists (14.5 to 65.2%) and diagnosis groups (11.1 to 93.4%). To optimize substitution initiatives like PC+, deliberation and further research is required.