This book is based on the proceedings of the fourth Medical Microcomputer Workshop held at the Middlesex Hospital Medical School on 3-5 September 1986. The workshop was attended by clinicians and computer scientists with an interest in applying computer technology to current medical practice. The problems ranged from audit and patient management through to the more complex applications of data analysis obtained from current diagnos tic techniques. The choice of microcomputers has never been greater with low cost making them readily available. A single microcomputer has limita tions in clinical practice and the use of networks for multi-user tasks has expanded its capability but increased the complexity both in terms of hardware and the software needed to run it. Although comprehensive commercial packages are available, none of these are entirely suitable for medical applications without modification. Many of the chapters presented in this book describe the problems encountered and the solutions achieved by configuring and modifying applications software.