In this concluding article, we summarize the major ways that seven registries and data sets have been used for technology assessment in the published literature. The registries fell into three groups according to the original purpose of the registry. Within each group, we note the types of contributions that researchers using the registries made to technology assessment.

Respiratory movements are controlled by two pairs of neuronal groups in the brain stem: nucl. tractus solitarius and nucl. paraambigualis. These neuronal pools receive drive inputs from the forebrain and hypothalamus, and from central and peripheral chemoreceptors (9). Whether there is endogenous spontaneous respiratory rhythmic activity has been a matter of controversy, but this has recently been discovered in brainstem preparations of the neonatal rat in studies by Onimaru and Homma (27).

Few major, community-based antismoking programs have undergone specific evaluation in developed countries; the number is even lower in developing countries. Yet not all evaluation need be elaborate, expensive, or overly time-consuming. Data on tobacco trade, import and export, taxation, mortality, and morbidity may already exist within government departments and can be used for evaluation. Published information from the tobacco industry may be obtained easily in trade journals and annual reports. Universities and international and overseas national health agencies may offer information, assistance, and expertise. Indirect evaluation of the importance of any particular antismoking intervention can be measured by how strongly the tobacco industry opposes that measure.

In an attempt to establish the extent to which patients and doctors agree on the outcome of health care, the pre- and postoperative states of health of 388 men undergoing transurethral resection of the prostate for benign disease were studied. Generally, high levels of concordance (>70%) were obtained. The strongest agreement was for clearly defined events, such as episodes of acute retention (95%); the weakest agreement occurred over the most subjective symptoms, prognostic expectations, and ambiguous terms (around 60%). The level of agreement was not associated with any characteristics of the patient, surgeon, or treatment.

This article first examines data bases available to assess the risk of vaccine-preventable diseases (VPD). In the second part, immunization recommendations and practices are briefly evaluated in view of the risk of exposure to VPD and of the efficacy and safety of available vaccines.

Extracorporeal membrane oxygenation (ECMO) is a means of diverting a fraction or all of the circulation through a device that permits gas exchange across a permeable membrane. The site of removal and the site of return of blood are dictated primarily by practical considerations based on the volume of flow of blood to be diverted and whether a particular organ is to be bypassed. The prototype of extracorporeal oxygenation is heart-lung bypass, used for various types of cardiac surgery, in which the entire venous return is diverted through an oxygenator (bubble or membrane type) and returned to the aorta. Since the earliest reports of the use of ECMO in neonates, venoarterial bypass has been the preferred route, with blood drained from the right atrium and returned either to the carotid artery or to the femoral artery, although the former seems to have been used most often (2;4;11;12;14;18). In some reports, veno-venous bypass has also been accomplished with removal of blood from the right atrium and return into the umbilical or femoral vein (13;19). Gas exchange across the lung may also continue, although the ventilator rate, tidal volume, or peak inspiratory pressure are usually reduced markedly during the period of extracorporeal oxygenation. Anticoagulation is accomplished with few problems by infusion of heparin sulfate throughout the duration of the procedure. There now have been enough reports in the literature (individual cases or series of patients) to demonstrate that the procedure can be carried out with a minimum of technical difficulties in newborn infants (2;3;4;11;12;18), although the selection of “appropriate” patients reduces the morbidity and technical challenges of the procedure.

This study assesses the nature, use, and quality of large administrative data bases available in different countries for technology assessment in health care. Using postal questionnaires, data were collected describing 91 data bases from 15 countries. Current uses are promising, but more efforts are needed if the full potential of administrative data files is to be tapped.

The objective of the study was to ascertain the extent of utilization of medical technologies (defined as equipment) used in various health care institutions in Nigeria. The study also investigated the factors accounting for use of and under- and nonutilization of this equipment. Sixteen major and minor health care institutions were surveyed. The outcomes of the study indicate that not less than a third of the equipment was out of order at the time of the study. A number of factors are responsible for nonutilization of this equipment. They include lack of infrastructural facilities such as piped water, storage, and power supply; poor handling by badly trained staff; and the low priority that is accorded to maintenance. The study leads to the important conclusion that the local culture is unable to sustain the technologies that are procured.

The articles in this issue of the International Journal of Technology Assessment in Health Care (IJTAHC) have explored the assessment of preventive health technologies. When considered together, these technologies provide an interesting contrast with the health care technologies that are usually evaluated on these pages. Disease prevention and its twin, health promotion, are usually practiced on a well population. Thus, many persons have the technology applied to them but only a fraction of these would have acquired the condition being prevented. Often the intervention is applied to populations rather than to individuals. The unit cost for preventive technologies is usually far less than that of diagnostic or therapeutic technologies. However, when multiplied by the larger population to be involved in the prevention program, the total costs can be considerable. In concluding this section on prevention, we would like to examine some of the larger areas of difference between preventive and other health technologies illustrated by the papers assembled here.

This paper examines how the decision-making process and its consequences affect medical technology transfer in major Chinese medical schools. Data are from a 1987 survey of 13 key medical universities, directly supervised by the Ministry of Public Health in the People's Republic of China. This paper limits itself to four types of laboratory equipment — electron microscopes, UV/VIS spectrophotometers, high-performance liquid chromatographs, and polygraphs. Decisions on the transfer of medical technology have been more decentralized in China since the economic reform in 1978. The major reason for schools to import these four types of equipment is their dissatisfaction with the quality of domestic products. Chinese medical schools depend heavily on the information provided at medical equipment exhibits and their neighboring schools. Their decisions to acquire the equipment are based more on the quality and service available than on the prices. Chinese medical schools face serious infrastructure problems in acquiring and maintaining these pieces of equipment. A number of suggestions are made for improving the efficiency of medical technology transfer in China.

Respiratory distress in newborn and young infants often develops as a result of acute lung injury, in which disruption of the normal barrier function of the pulmonary endothelium and epithelium causes protein-rich interstitial and alveolar edema. Several conditions may initiate acute lung injury, including aspiration of meconium or gastric contents, bacterial or viral infection, overzealous resuscitation, and birth associated with incomplete lung development that requires ventilatory support with positivepressure mechanical ventilation and high concentrations of inspired oxygen. The latter condition usually occurs after premature birth, but it also may occur as a consequence of impaired fetal lung growth secondary to diaphragmatic hernia or chest compression from lack of liquid in the amniotic cavity. Acute lung injury sometimes progresses to a chronic form of lung disease, which is characterized by edema, fibrosis, airway distortion, and nonuniform inflation of the lungs.

An economic evaluation was undertaken concurrently with a randomized trial comparing a Caregiver Support Program (CSP) with existing conventional community nursing care for those caring for elderly relatives at home. The differences in resource consumption were compared with changes in caregiver quality of life, as measured by the Caregiver Quality of Life Instrument (CQLI). A 20% difference from baseline in the CQLI favored the experimental (CSP) group, although this did not reach conventional levels of statistical significance. A comparison of improvement in quality of life with costs implies an incremental cost per quality-adjusted life year gained of Canadian $20,000 for the CSP, which compares favorably with other health care interventions. Further, larger studies are required to confirm this result.

The majority of technologies in use in perinatal care were organized into 45 technological functions. Forty-six experts from 19 different regions of Brazil and other Latin American countries then selected a “basic package” (BP) of 15 technological functions. Considering the 12 main causes of perinatal mortality in Brazil, the experts estimated the number of preventable deaths, assuming universal coverage by the BP and the additional reductions that could be obtained by gradually adding other technological functions to the BP. A simulation was performed for the 26 states of Brazil to identify regional priorities for the diffusion of technological functions. For most regions, the BP appears to be the most effective intervention, with the potential of reducing perinatal mortality by 33%, followed by “coordination of services and referral of pregnant women” (14%), and “treatment of respiratory conditions” (11.8%).

Bronchopulmonary dysplasia (BPD) is a progressive disorder of the lungs of newborn infants initially involving distal airways, but followed in weeks by the development of abnormalities in all parts of the lung architecture. BPD develops primarily but not exclusively in premature infants. The incidence in the general population has never been assessed accurately in a prospective manner. One retrospectively calculated incidence figure is 1.2 infants per 1,000 total live births per year in the United States (17). With approximately 4 million births annually in North America, there are about 5,000 babies each year who develop BPD. The additional weeks, months, and, in some cases, years of hospitalization, the frequent rehospitalizations, and the mortality of 20–50% beyond 1 month of age (17) underscore the disproportionate financial and emotional toll of BPD not only on patients and families but caregivers as well. The glacial rates of improvement in the illness, the frequent setbacks, and the profound disruption to family life all support the contention that BPD is a major public health problem.

Controlled clinical trials are recognized as the best source of data on the efficacy of health care interventions and technologies. Because economic evaluation is dependent on the quality of the underlying medical evidence, clinical trials have increasingly been viewed as a natural vehicle for economic analysis. However, the closer integration of economic and clinical research raises many methodological issues. This paper discusses these issues in trial design, collection of resource use data, collection of outcome data, and interpretation and extrapolation of results. Some guidelines are suggested for economic analysts wishing to undertake evaluations alongside clinical trials.

The present study compares the cost of antitumor therapy and adverse cardiovascular effects during the first year of treatment with oral estrogens, nonoral estrogens, or surgical castration in patients with prostatic cancer. We found a much higher cost for patients treated with orchidectomy and oral estrogens than for patients treated with nonoral estrogens. Twenty-five percent of the patients treated with oral estrogen suffered cardiovascular complications, compared to none of the patients treated by orchidectomy or nonoral estrogens. The initial cost of orchidectomy as compared to nonoral estrogen treatment was shown not to be balanced within the expected survival time of patients with advanced prostatic cancer. Furthermore, surgical castration causes psychological trauma to the patient. We recommend parenteral estrogen therapy as a low-cost therapeutic regimen in patients with prostatic cancer.