[++Scintimammography: a new imaging technique for diagnosis and follow-up of breast cancer]. / Apport de la mammoscintigraphie 99m Tc MiBi dans le diagnostic et le suivi des cancers du sein.

99m Tc MiBi has emerged as a new imaging technique for primary breast carcinomas. The aim of this study was to analyze the diagnostic performance and the additional information provided by scintimammography (SMN). Two hundred and forty consecutive women referred to surgery for abnormalities breast or suspicious breast cancer were scanned before surgery. Sensitivity and specificity were respectively 92% and 53%. PPV: 77.5% and PVN: 79.3%. All false negative scans occurred in cancers 1 cm. SMN detected multiple foci of uptake in the same breast in 13%, that were all confirmed to be multifocal disease and histology. Controlateral focal uptake was also detected; at this time 5/27 are confirmed to be bilateral breast neoplasms; 22 patients are in follow-up. SMN is reliable in the diagnosis of breast cancer and also with difficult cases of mammography. Moreover, SMN provides additional qualitative information in 19.6% of breast carcinomas, such as chest wall infiltration, multifocal or bilateral breast cancer.

Cost-minimization analysis of treatment options for T1N0 glottic squamous cell carcinoma: comparison between external radiotherapy, laser microsurgery and partial laryngectomy.

BACKGROUND AND PURPOSE: A cost minimization analysis of radiotherapy (RT), laser microsurgery (L) or partial laryngectomy (PL), which are equally effective options for T1N0 glottic SCC was carried out from the perspective of the National Health Care System. METHODS: For each modality, the various events associated with the diagnostic procedure, the primary treatment, the complications, and the salvage treatment were individualized. The charges of each of these events weighted for the frequency of occurrence were then determined using the 'fee for service' policy established by the National Health Insurance of Belgium. RESULTS: A total cost of 5172, 5847 and 11563 EURO were calculated for RT, L and PL, respectively. For L, cost included post-operative RT applied in case of positive margins (30%). For PL, the cost of the primary treatment accounted for 68% of the total cost whereas it only accounted for 50 and 43% for L and RT, respectively. For RT, L or PL, complications accounted for less than 10% of the total cost. The cost of salvage treatment reached 19, 14 and 8% of the total cost for RT, L and PL, respectively. A sensitivity analysis indicated that reduction of the duration of hospitalization decreases the costs without affecting the ranking between the three options. Also, the cost of L could be reduced even slightly below the cost of RT by decreasing the need for post-operative RT. CONCLUSIONS: RT and L have almost the same expected average cost for the treatment of T1N0 glottic SCC, whereas PL is twice as expensive.

[Economic analysis of diagnostic and therapeutic methods in cases of cold thyroid nodules]. / Analyse économique des approaches diagnostiques et thérapeutiques du nodule froid de la thyroïde.

This article studies how two diagnostic tests (cytological puncture and 201thallium scanning) can be combined to obtain a more efficient approach of cold thyroid nodules. Diagnostic and therapeutic approaches are compared on the basis of four criteria: financial cost (immediate and delayed), number of labelled cancers, pre- and postoperative death rates and number of complications.

[Determination of cost-effective strategies in colorectal cancer screening]. / Détermination de stratégies coût-efficaces dans le dépistage du cancer colorectal.

The object of the article is to implement particular methodologies in order to determine which strategies are cost-effective in the mass screening of colorectal cancer after a positive Hemoccult test. The first approach to be presented consists in proposing a method which enables all the admissible diagnostic strategies to be determined. The second approach enables a minimal cost function to be estimated using an adaptation of "Data Envelopment Analysis". This method proves to be particularly successful in cost-efficiency analysis, when the performance indicators are numerous and hard to aggregate. The results show that there are two cost-effective strategies after a positive Hemoccult test: coloscopy and sigmoidoscopy; they put into question the relevance of double contrast barium enema in the diagnosis of colo-rectal lesions.

Clinical and economic evaluation of health care technologies: a joint and sequential approach.

Promising new technologies have to be carefully analyzed before their integration into clinical practice. Moreover, the existing technologies need to be confronted with the new ones in terms of effectiveness and efficiency. Logical guidelines for both clinical and economic evaluation are described in the present review paper which mainly deals with diagnostic technology. All the proposed steps are not instrumental for each technology assessment but they provide a more rational approach to the acceptance and diffusion of technology.

[Diagnostic value of thallium 201 scintigraphy in the determination of malignancy of cold thyroid nodules]. / La valeur diagnostique de la scintigraphie au thallium 201 dans la détermination de la malignité du nodule froid thyroïdien.

In this paper we discuss and quantify the respective values of Thallium 201 scintigraphy and cytologic punction in determining malignancy of the cold thyroid nodule. These two diagnostic tests are evaluated on the basis of their sensitivity and specificity while taking into consideration various therapeutic attitudes in the presence of a cold thyroid nodule.

To test or not to test--to treat or not to treat: the decision-threshold approach to patient management.

The inability to consider explicitly factors that should enter into clinical judgment compromises physician efforts to make cost-effective decisions regarding diagnostic testing and treatment. The authors describe the decision-threshold approach, a decision-analysis strategy that helps physicians identify an optimal test-treatment decision based upon the prior probability of disease, the characteristics of the test (sensitivity, specificity, risk), and the benefits/costs of treatment. They also present a microcomputer graphics program that makes the decision-threshold approach readily available to physicians.

Risk-aversion and physicians' medical decision-making.

In this paper, we examine a physician's optimal therapeutic decisions in a risky environment as well as his response to exogenous changes such as increased risk-aversion or improvements in medical technology. We also analyze the value of diagnostic information and its relationship with risk-aversion.

The determinants of biological prescription in French hospitals.

We present in this paper the first stage of a broader work, the aim of which is to better understand the volume, modalities, determinants and cost-benefit ratio of the medical prescription in hospitals. Through a sample of 1800 patients observed in 1978 and 1979, in 18 medical or surgical services of 6 French hospitals of different size, statute and location, we have pursued a double objective: first, to establish the basic elements of an 'observatory' of the biological prescription in order to quantify this prescription; secondly, to shed some light on the factors which might explain the differences observed between hospitals, services and diseases. Linear and non-linear econometric models have been used to perform the analysis of the 252,000 data that had been collected. This research has given rise to an evaluation of the informative content of the diagnostic tests ordered by the physicians. This analysis is discussed further in the present volume.

The medical and economic consequences of automation in bacteriology: a case study in a French university hospital.

In a bacteriology laboratory where automated and non-automated procedures co-existed during the study period (1 year), patients were randomly assigned to each type of procedure and we observed the physicians behaviour as well as patients well-being in a surgical service using the results from the laboratory. Contrary to our expectations, the reduction in the time delay necessary to obtain information did not alter either the prescribing behaviour of physicians nor the welfare of patients. Besides, the gain in time was significantly lower than expected. We also discuss in detail the meaning and relevance of the results.

The informative content of radiography and scintigraphy in the diagnosis of bone metastases after breast cancer.

In this paper we apply decision theory to evaluate the efficiency of diagnostic procedures. In the case we discuss, we compute the value of scintigraphy and radiography used separately or in combination in the diagnosis and treatment of bony metastases after breast cancer.

The informative content of diagnostic tests: an economic analysis.

In medical literature the value of diagnostic tests is most of the time appreciated from their statistical properties (sensitivity and specificity) and from the prevalence of a given disease. In this paper we also take into account economic parameters such as the benefits and costs of the potential treatment under consideration and we present a simple and flexible algebraic expression of the informative value of a test. In this way the informative content of a test can be easily evaluated and the quality of an existing test can be compared to that of a theoretically 'perfect' one. Two examples taken from the medical literature illustrate our approach.