Two questionnaires were filled in for every patient in the study. The first was completed during the patient's hospital stay by the doctor immediately concerned and detailed, for every test requested, the following information: date of request, name of test, category of request (see below), and expected result. Tests were graded as non-discretionary (that is, depending upon known policy rather than doctor's clinical judgement), diagnostic, monitoring, or checking (when a test result was thought to be mistaken).The second questionnaire was filled in by a research worker and the clinician together a fortnight after admission, or upon discharge, whichever was sooner. For every test the result and the action taken were recorded. SUMMARY The use oflaboratory tests in the management of 174 randomly selected patients admitted as acute medical emergencies was monitored in detail. The occasions when a test result changed patient management, and the nature of that change, were noted. Tests were classified according to information yielded and the importance of any action taken. For biochemistry alone every test result was costed. A ranking for all tests was produced, in terms of expected actions per test, and for biochemistry a 'value for money' table giving actions per pound spent. Every test request was classified as either discretionary or non-discretionary. The discretionary category was further subdivided into diagnostic and monitoring. The values, in terms of action-producing results, of non-discretionary, diagnostic, and monitoring tests were compared, and this comparison showed that the cost per item of helpful information was about £10 for diagnostic, £23 for monitoring, and £20 for non-discretionary tests. In total, £1790 was spent, and 28 items of unique information were yielded, enabling clinicians to discharge five patients, take seven courses of action which would have had serious consequences if omitted, and 16 actions the omission of which would have led to very serious consequences.
Ann Clin Biochem
