Varicose vein clinics: modelling the effects of seasonal variation in referrals

Data have been collected prospectively on patients referred to a specialist varicose vein clinic between January 1991 and December 1994. A seasonal variation in referral pattern of patients is demonstrated, with more patients being referred in the summer months. Similar fluctuations are seen in the number of patients waiting for first appointment, and the average waiting time for first appointment. Such fluctuations in referral patterns can lead to difficulties in planning. A computer model has been constructed and used to predict future referrals and the effects of seasonal variations upon waiting times for appointments and on efficiency of clinic usage. The computer model accurately predicts numbers of future referrals. The average waiting time for first appointment could be kept constant by arranging more varicose vein clinics in summer than in winter but keeping the overall number of clinics during the year constant. The computer model could be important in planning of specialist clinics, and may play a role when negotiating future contracts. If flexibility can be achieved by exchanging clinics with different seasonal patterns, it may be possible to reduce waiting times within existing resources.