Walley outlines some of the problems encountered in evaluating laboratory diagnostic tests.1 One of the great difficulties faced by organisations such as the National Institute for Health and Clinical Excellence (NICE) is to find a means to prioritise diagnostic technologies for rapid evaluation. I have recently developed the following prioritisation criteria for use by organisations.
The disease
Can the disease be clearly defined?
Is the condition an important problem in terms of prevalence and incidence or morbidity and mortality?
Is it a policy priority?
Does the condition present a diagnostic problem (inaccuracy or inefficiency), and would it be useful to have better diagnostic tools?
Is there evidence of current variation in diagnostic practice (or inappropriate variations in treatment, morbidity, or mortality resulting from diagnostic variability)?
Could the diagnostic processing pathway for the disease be improved by obtaining information in a less risky fashion or in a manner more acceptable to patients?
The diagnostic technology (history and examination, physiological measurement, imaging, endoscopy, pathology)
Is there clarity about the purposes and the costs of this technology in the context of a diagnostic processing pathway?
Has the safety and analytical validity been established, and is it CE marked?
Is there evidence of clinical validity in the appropriate setting?
Are there opportunities for enhanced efficiency or cost savings in relation to the current diagnostic processing pathway if this technology were more widely employed?
In the absence of an appraisal, is there any likelihood of “drift” with overuse or inappropriate use of this technology?
Is it feasible to change current practice to incorporate this technology (for example, by considering additional requirements for training, infrastructure, and quality control)?
The impact of the diagnostic technology
Is there an effective treatment for the target condition, and could greater diagnostic precision using the technology lead to better targeted treatment delivery?
Is there an effective treatment for the target condition, and could more rapid diagnosis using the technology lead to shorter treatment delays?
Would better diagnosis result in lowered morbidity and mortality both from the disease and from the diagnostic process?
Competing interests: NS is currently undertaking a review for NICE on the institute’s approach to diagnostic technology evaluation.
References
- 1.Whalley T. Evaluating laboratory diagnostic tests. BMJ 2008;336:569 [DOI] [PMC free article] [PubMed] [Google Scholar]