From azucchi@asl.bergamo.it Tue May 4 03:33:31 1999 Received: from mxu4.u.washington.edu (mxu4.u.washington.edu [140.142.33.8]) by lists.u.washington.edu (8.9.3+UW99.02/8.9.3+UW99.01) with ESMTP id DAA47614 for ; Tue, 4 May 1999 03:33:30 -0700 Received: from enterprise.asl.bergamo.it ([194.179.159.10]) by mxu4.u.washington.edu (8.9.3+UW99.02/8.9.3+UW99.01) with SMTP id DAA07036 for ; Tue, 4 May 1999 03:33:27 -0700 Received: by enterprise.asl.bergamo.it(Lotus SMTP MTA SMTP v4.6 (462.2 9-3-1997)) id C1256767.0039F9DE ; Tue, 4 May 1999 12:33:15 +0200 X-Lotus-FromDomain: AZIENDA USSL 12 BERGAMO From: "Alberto Zucchi" To: waphgis@u.washington.edu Message-ID: Date: Tue, 4 May 1999 12:32:43 +0200 Subject: Hospitals catchment area Mime-Version: 1.0 Content-type: text/plain; charset=us-ascii Dear Listers, I'd like to receive some suggestion on the following problem. I have a data-set containing all paediatric admissions (say, 200,000) in all the hospitals in a region (say, 30). I have two tables. The first contains hospitals' localization (with related coordinates). The second contains each admissions these hospitals did in one year, with each patient's city of residence (say approx. 200,000 patients for 2,000 cities/villages). I'd like to create a "catchment area" for each hospital, in relation to their patients' residence. I thought to build a "distance matrix" in kilometres, and the calculate the mean or median distance for each city/hospital, and finally superimpose a "buffer" (or maybe drawing a simple circle...to simplify reality). Does anyone have some suggestion/trick on the way to perform this? Thank you in advance. Alberto Zucchi, MD Epidemiology Office ASL Bergamo .