The current medical environment makes information retrieval a matter of practical importance for clinicians. Many avenues present themselves to the clinician, but here we focus on MEDLINE by summarizing the current state of the art and providing an innovative approach for skill enhancement. Because new search engines appear rapidly, we focus on generic principles that can be easily adapted to various systems, even those not yet available. We propose an idealized classification system for the results of a MEDLINE search. Type A searches produce a few articles of high quality that are directly focused on the immediate question. Type B searches yield a large number of articles, some more relevant than others. Type C searches produce few or no articles, and those that are located are not germane. Providing that relevant, high-quality articles do exist, type B and C searches may often be improved with attention to search technique. Problems stem from poor recall and poor precision. The most daunting task lies in achieving the balance between too few and too many articles. By providing a theoretical framework and several practical examples, we prepare the searcher to overcome the following barriers: a) failure to begin with a well-built question; b) failure to use the Medical Subject Headings; c) failure to leverage the relationship between recall and precision; and d) failure to apply proper limits to the search. Thought and practice will increase the utility and enjoyment of searching MEDLINE.

Biomedical databases are an important source of information for health technology assessment. However, there is considerable variation in the costs of accessing commercial databases. We sought to measure the quality, amount of overlap, and costs of information retrieved from two of the main database sources — MEDLINE and EMBASE. Librarians at two health technology assessment agencies ran a total of eight literature searches on various medical technologies, using both databases. All search results were independently reviewed by two researchers. The researchers were asked to identify relevant references and to rank each of these according to a level of evidence scale. The results were tabulated to show the number of references identified by each database, the number of relevant references ranked by level of evidence, and the number of these references that were unique to one or the other database. The cost of retrieving references from each source was also calculated. Each database contained relevant references not available in the other. Because of the longer time lag for indexing in MEDLINE, many of the references that originally appeared to be unique to EMBASE were subsequently available in MEDLINE as well. Since our study was conducted, MEDLINE has been made available worldwide, free of charge, via the Internet. Hence, the cost difference between the databases is now even greater. However, notwithstanding the costs, it appears that literature searches that rely on only one or the other database will inevitably miss pertinent information.

Meta-analysis is commonly used in reviews of the effectiveness of medical technologies, but this approach has not been used in direct support of guidelines development groups. This paper describes the approach of the North of England Guidelines Development Project in describing the evidence using meta-analyses that were conducted explicitly to address questions on the choice of therapy raised by the guidelines development groups. Particular emphasis is placed on the context within which the contributing trials were conducted and the extent to which systematic differences between trials (heterogeneity) was observed, described, and explained. There is a trade-off between internal and external validity for different metrics when presenting the results of trials. More interpretable metrics, such as risk differences or weighted mean differences, are confounded by study design issues and strong assumptions. More robust measures such as odds ratios or standardized weighted mean differences are difficult to interpret physically. Individual patient data may prove particularly helpful in addressing pivotal questions on the magnitude of effects of interventions, though accessing and reanalyzing these data requires a substantial investment in time and other resources.

After 25 years of debate about privacy of automated personal health data, the U.S. Congress has set a deadline of August 1999 for enacting health information privacy legislation. The urgency to establish national policy in the United States re-emerges with implementation of a 1996 law mandating a unique identifier for each participant in the U.S. medical care system and the use of a uniform electronic data set for all health information transmitted in financial and administrative transactions. The impact of electronic data storage and transmittal on privacy, health outcomes, and medical care is unclear. A three-step analytic scheme can clarify the issues in the policy debate and for future assessment. The first step is intended to elicit, for the first time, a precise, accurate, and reproducible description of personal health data transactions and chains of transactions, independent of the policy preferences of any interested party. The second step allows the reader to analyze these transactions according to who benefits first and foremost from each. This scrutiny clarifies the reasons why parties to the debate tend to disagree. The third step characterizes how Congress is likely to perceive the policy process and consider its options before enacting any particular set of compromises. Understanding the policy deliberations and potential effects of evolving information technologies and new national privacy rules should aid assessment of results.

The need to choose among alternatives instead of allowing the market to make choices has led health care professionals to rely on scientific information as an aid in decision making. Mathematical modeling is one of the increasingly common tools used over the past three decades to produce new information. But we have used almost exclusively noncomplex models to help analyze complex systems problems. The need to integrate the complexity of the interactions of clinical, quality of life, and economic attributes into such models can no longer be ignored. The opportunity is available to use existing complex systems modeling techniques for health care questions to improve the quality of study outputs, which can, in turn, help produce more rational decisions.

The economic technique of conjoint analysis was used to assess the relative importance of health outcome versus several process attributes (e.g., waiting time, continuity of contact with the same medical staff) in determining patients' preferences for liver transplantation services. The attributes were established by reference to the literature and through initial qualitative interviews with liver transplant recipients (n = 12). Following a pilot study of 40 patients, a sample of patients (n = 213) who have received a liver transplant at the Queen Elizabeth Hospital in Birmingham were surveyed. The technique of conjoint analysis was used to ascertain the relative importance of the attributes included in the exercise and to estimate the marginal rates of substitution (MRS) between different attributes. A useable response rate of 89% was achieved. Although a small proportion of respondents (15%) exhibited dominant preferences for the chance of success attribute, the majority of respondents indicated that they would be prepared to exchange a reduction in health outcome for an improvement in the process characteristics of the liver transplantation service. The results of this study have potentially important implications for the assessment of the benefits of medical technologies since they suggest that, even in the extreme case of life-saving interventions, the preferences of respondents may not be dependent solely upon health outcomes but may also be determined by attributes associated with the process of care.

This paper gives a detailed presentation of a computer model for evaluating the cost-effectiveness (CE) of hormone replacement therapy (HRT), describing the model's design, structure, and data requirements. The model needs data specified for costs, quality of life, risks, and mortality rates. As an illustration, the CE of HRT in Sweden is calculated. Two treatment strategies are evaluated for asymptomatic women: estrogen-only therapy and estrogen combined with a progestin. The model produces similar results compared with earlier studies. The CE ratios improve with the size of the risk reduction and generally with age. Further, estrogen-only therapy is associated with a lower cost per gained effectiveness unit compared with combined therapy. Uncertainty surrounding the long-term effects of HRT means that the CE estimates should be interpreted carefully. The model permits the inclusion of indirect costs and costs in added life-years, allowing the analysis to be made from a societal perspective, which is an improvement relative to previous studies.

This paper describes a method to construct a standardized health care resource use database. Billing and clinical data were analyzed for 916 patients who received liver transplantations at three medical centers over a 4-year period. Data were checked for completeness by assessing whether each patient's bill included charges covering specified dates and for specific services, and for accuracy by comparing a sample of bills to medical records. Detailed services were matched to a standardized service list from one of the centers, and a single price list was applied. For certain services, clinical data were used to estimate service use or, if a match was not possible, adjusted charges for the services were used. Twenty-three patients were eliminated from the database because of incomplete resource use data. There was very good correspondence between bills and medical records, except for blood products. Direct matches to the standardized service list accounted for 69.3% of services overall; 9.4% of services could not be matched to the standardized service list and were thus adjusted for center and/or time period. Clinical data were used to estimate resource use for blood products, operating room time, and medications; these estimations accounted for 21.3% of services overall.

A database can be constructed that allows comparison of standardized resource use and avoids biases due to accounting, geographic, or temporal factors. Clinical data are essential for the creation of such a database. The methods described are particularly useful in studies of the cost-effectiveness of medical technologies.

The authors performed a meta-analysis to determine whether open or laparoscopic appendectomy would reduce wound infection incidence in adult patients with acute appendicitis. The meta-analysis included nine of seven patients from eight randomized controlled trials. Data were analyzed using the fixed effect-model method of Mantel-Haenszel. Wound infection incidence was lower in the laparoscopic group.

Magnetic resonance imaging (MRI) has excellent specificity and sensitivity for the diagnosis of internal derangement of the knee (IDK). The use of MRI to screen patients with suspected IDK could avoid unnecessary arthroscopies with a reduction in costs. The purpose of this study was to evaluate the use of arthroscopy among patients with IDK, and to estimate the potential cost-effectiveness of MRI in these patients to avoid unnecessary arthroscopies. The study was based on a retrospective cohort of all patients attending three orthopedic clinics between April and September 1993 with a new diagnosis of IDK. Charts were reviewed in 1994 to allow for a follow-up of more than 6 months. An economic evaluation was performed based on cost-effectiveness ratios (per averted arthroscopy), including direct and indirect costs. There were 241 patients with a new diagnosis of IDK (67% males, mean age 35 ± 12 years), and 110 (46%) underwent arthroscopy. The remaining patients received conservative therapy and were not scheduled for arthroscopy within the period of observation. Using a priori established criteria, 10% of the arthroscopies could be considered diagnostic only (e.g., normal knee) and 27% were of doubtful efficacy from a therapeutic perspective (e.g., debridement alone). Many of these arthroscopies could have been avoided by performing a prior MRI. Using these findings, we conducted decision tree analyses of the use of MRI among patients requiring arthroscopy of the knee. A sensitivity analysis was performed to evaluate the various model assumptions. In general, MRI appeared to be a cost-effective diagnostic procedure for patients with IDK requiring arthroscopy of the knee, and there were cost savings associated with it in some of the models tested.

While reversible cases of dementia are rare once detected, the patient may benefit from treatment. This paper examines the cost-effectiveness of computerized tomography (CT) scanning as a screening test for potentially reversible dementia. A systematic review was carried out to identify the proportion of patients with dementia above and below the age of 65 years with a theoretically treatable condition and the proportion of these patients who would benefit from neurosurgery. Information was combined with epidemiological and financial data relating to Scotland to model the costs and benefits of implementing a national screening program. Subdural hematoma, normal pressure hydrocephalus, and brain tumours are rare conditions treatable by neurosurgery. A scanning and treatment program for Scotland would cost £4.6 million per annum. Of 531 reversible cases detected, 136 would benefit from neurosurgery, 369 would not benefit, and 26 would die as a result of surgery. Treating normal pressure hydrocephalus reduces overall quality-adjusted survival. The most cost effective screening strategy is to scan all patients but treat only subdural hematomas, gaining 178 quality-adjusted life-years (QALYs) at a cost of £14,171 per QALY for patients aged 65 at the time of the scan. The corresponding figures for patients above and below 65 years are £9,000 and £23,000, respectively. CT scanning appears cost-effective in dementia patients under 65 years. It should be undertaken selectively in more elderly patients. Surgical treatment of normal pressure hydrocephalus may reduce quality adjusted survival and should only be undertaken within clinical trials.

Recombinant human erythropoietin (Epo) use represents a substantial pharmaceutical expense for UHC hospital members. In 1997 it ranked second to filgrastim (G-CSF), with UHC member annual purchases totaling more than $23 million.

This qualitative review describes the current molecular basis of breast and prostate cancer, assesses the clinical relevance of genetic susceptibility, addresses nondirective counseling, and explores the ethical, psychosocial, and policy implications associated with genetic testing.

Ultrasound examination in conjunction with pregnancy was introduced nearly 25 years ago. At the outset, this technology was used mainly in cases of suspected morbidity or fetal malformation. As ultrasound technology has advanced, the indications for this type of examination have also expanded, and all pregnant women in Sweden are now offered an ultrasound examination at least once during their pregnancy. In Sweden an average of slightly more than two ultrasound examinations are performed per pregnant woman, including examinations performed for medical indications. More than 95% of women who deliver have undergone routine ultrasound examination.