Rationing out-patients: a defence of the waiting list.

New psychiatric out-patients were offered immediate or delayed appointments (average delay 12 weeks) in random order. The two groups thus formed, comprising 234 patients, were shown to be comparable in some important respects. Immediate appointments were taken up significantly more frequently than delayed appointments, and 12 per cent of immediate and 22 per cent of delayed patients did not receive any psychiatric service. No evidence was found that delay increased other medical services supplied. Non-attenders were presumed to suffer from "neurosis" and "personality problem". Initial attenders used more services than those who failed to keep their first appointment but came later. A waiting list is proposed as a screening device to limit out-patient referrals.