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At least 73 records · Page 4Linked to original sources
PubMed2003

Lifetime costs for medical services: a methodological review.

OBJECTIVES: Guidelines for economic evaluation studies recommend that modeling be undertaken to estimate long-term, downstream costs. In this study, we conduct a review of a sample of studies that estimated the lifetime medical care costs for a variety of conditions. METHODS: We developed a categorization of the elements for a lifetime-costing study and based on these elements, we abstracted information from a sample of 33 papers in the following areas: study subject, purpose, scope, methods (including time profile, utilization, and cost), and results. RESULTS: We analyzed papers that were observational, models or that combined the two approaches. The time profiles were estimated from registry and published data. Utilization data were obtained from administrative data, chart reviews, and professional opinion. Costs were obtained from administrative and financial records and were estimated using all charges, allocated costs, and provider payments. We noted wide variations in methods and reporting practices. CONCLUSIONS: Following current guidelines (CCOHTA), lifetime models can be more easily interpreted and applied if investigators are more clear in their study aims, if they incorporate assumptions that are based on current data, if they follow current methodological practices (such as deflation, discounting, and sensitivity analyses), and if reporting is more transparent.

Canada↗
PubMed2000

Considering clustering: a methodological review of clinical decision support system studies.

Computer-based clinical decision support systems (CDSSs) are often implemented at a cluster level, but standard statistical methods for sample estimation and analysis may not be appropriate for such studies. This review aims to determine whether the design and analysis methods of cluster-based studies were adequately addressed in reports of CDSS studies. We retrieved 61 reports of the CDSS controlled trials and identified 24 studies meeting our inclusion criteria. Of these, none included sample size calculations that allowed for clustering, while 14 (58%) took account of clustering in the analysis. Although there is increasing recognition of the methodological issues associated with cluster design in health care, many medical informaticians are still not aware of these issues. Investigators should publish estimates of the intracluster correlation coefficients and variance components in their reports to guide the planning of the future studies.

Cluster Analysis↗
PubMed1995

Efficacy of vitamin B6 and magnesium in the treatment of autism: a methodology review and summary of outcomes.

Pauling's orthomolecular hypothesis appeared in 1968, stating that some forms of mental illness and disease are related to biochemical errors in the body. Vitamin therapy is believed to be a means of compensating for such errors. There have been few empirical studies on vitamin therapy in individuals with autism. This article presents a critical analysis of the 12 published studies located through an extensive computerized search. Studies were systematically evaluated to provide an objective assessment of empirical evidence supporting the efficacy of vitamin treatment. The majority of studies report a favorable response to vitamin treatment. However, interpretation of these positive findings needs to be tempered because of methodological shortcomings inherent in many of the studies. For example, a number of studies employed imprecise outcome measures, were based on small samples and possible repeat use of the same subjects in more than one study, did not adjust for regression effects in measuring improvement, and omitted collecting long-term follow-up data. Recommendations are offered to assist researchers in designing future investigations.

Autistic Disorder↗
PubMed1992

Monitoring chemical exposure using breast milk: a methodological review.

Retrospective exposure assessments are often a major weakness in environmental epidemiologic studies. Many environmentally important chemicals are persistent lipophilic compounds which partition into fat and breast milk. The analysis of these chemicals in breast milk provides a noninvasive means of collecting large volumes of a biologic fluid that correlates well with body burden. This may provide an integrated measure of cumulative absorption over several years which can be used to assess exposure in several different epidemiologic study designs. However, consideration of toxicokinetic principles in the study design is important in order to allow for maternal and other factors unrelated to exposure which may influence breast milk concentrations. These factors include maternal age, parity, maternal body weight, time of sampling during the lactation period, and fat content of the breast milk. Failure to use standardized entrance criteria and to allow for the above factors in the analysis and interpretation of the study results may lead to invalid conclusions regarding past exposures. Allowance must also be made for the restrictions on the sampling frame available in any epidemiologic study using breast milk analysis. Published studies to date often have had several methodological deficiencies. With the introduction of biologic specimen banks, breast milk collection and analysis should play an important role in future epidemiologic studies, especially those investigating health outcomes in infants.

Body Weight↗
PubMed1993

HIV prevalence among IDUs in Australia: a methodological review.

A review was carried out of Australian studies which have measured the prevalence of HIV infection among injecting drug users (IDUs). The review considered published studies which had reported on serologically-determined HIV prevalence. There were five studies reported from specialized sexually-transmissible disease of HIV clinics, five studies reported from health services aimed at IDUs, three studies reported from other health services and one multi-centre behavioural study. The main findings from the studies were that HIV prevalence in IDUs has been low in Australia, apart from in male IDUs who also had homosexual contact. HIV prevalence ranged from 20 to 24% in male IDUs reporting homosexual contact and from 0 to 5% in other IDUs.The studies, while reflecting a range of research methodologies, are subject to a number of limitations. Most of the studies did not provide detailed analyses of HIV prevalence by age and sex or behavioural factors, and several studies used sampling frames which were not clearly defined. There is little available information on temporal trends in seroprevalence and geographical comparisons are rendered difficult by differences in the study methodology. Adoption of standardized, continuing seroprevalence surveys on IDUs would provide a better means of monitoring the occurrence of HIV infection in this group, which has been a key determinant of the course of the HIV epidemic in a number of Western countries.

Journal Article↗
PubMed2006

Assessing cross-cultural validity of scales: a methodological review and illustrative example.

In this article, we assessed the cross-cultural validity of the Women's Role Strain Inventory (WRSI), a multi-item instrument that assesses the degree of strain experienced by women who juggle the roles of working professional, student, wife and mother. Cross-cultural validity is evinced by demonstrating the measurement invariance of the WRSI. Measurement invariance is the extent to which items of multi-item scales function in the same way across different samples of respondents. We assessed measurement invariance by comparing a sample of working women in Taiwan with a similar sample from the United States. Structural equation models (SEMs) were employed to determine the invariance of the WRSI and to estimate the unique validity variance of its items. This article also provides nurse-researchers with the necessary underlying measurement theory and illustrates how SEMs may be applied to assess cross-cultural validity of instruments used in nursing research. Overall performance of the WRSI was acceptable but our analysis showed that some items did not display invariance properties across samples. Item analysis is presented and recommendations for improving the instrument are discussed.

Analysis of Variance↗
PubMed1998

Treatment of Medicaid patients with asthma: comparison with treatment guidelines using disease-based drug utilization review methodology.

OBJECTIVE: To compare asthma drug therapy in the Iowa Medicaid population with international treatment guideline recommendations and relate differences to patient outcomes. METHODS: Data on asthma drug therapy and respiratory-related medical services (clinic visits, emergency visits, hospital admissions) were abstracted from prescription claims and diagnostic codes of adult Iowa Medicaid patients with asthma (n = 1029). RESULTS: About two-thirds of the population received a prescription for a short-acting beta 2-agonist during the study period. Patients with greater daily use of short-acting beta 2-agonists had more clinic visits (p = 0.004), likely related to illness severity. Almost one-third (29.3%) of 58 patients receiving a prescription of salmeterol did not receive the recommended prescription of a short-acting beta 2-agonist inhaler in the 6-month period. About one-half of patients who should have been prescribed inhaled corticosteroids according to the international guidelines did not receive such a prescription in the 6-month study period. Increased use of inhaled corticosteroids was associated with fewer (p = 0.04) emergency visits. CONCLUSIONS: Suboptimal asthma treatment in the Iowa Medicaid population, especially in regard to the use of inhaled corticosteroids as preventive therapy, was evident after comparison with treatment guidelines. Increased daily use of inhaled corticosteroids was associated with positive patient outcomes in accordance with guideline recommendations. Educational efforts to improve closer adherence to international guidelines both in prescribing practices and patient compliance with medication for asthma management should be undertaken.

Administration, Inhalation↗
PubMed1996

Economic evaluation of prenatal diagnosis: a methodological review.

This paper discusses the role of economic evaluation in prenatal diagnosis. As the availability of new and improved techniques of prenatal diagnosis increases, so does the relevance of economic evaluation. The various methods of economic evaluation are discussed in the context of amniocentesis and chorionic villus sampling. It is argued that in view of the potentially wide range of benefits from prenatal diagnosis, more sophisticated measures of benefit should be incorporated into economic evaluations. Further development of utility-based measures and monetary valuation is suggested.

Adult↗
PubMed2005

QALY maximisation and people's preferences: a methodological review of the literature.

In cost-utility analysis, the numbers of quality-adjusted life years (QALYs) gained are aggregated according to the sum-ranking (or QALY maximisation) rule. This requires that the social value from health improvements is a simple product of gains in quality of life, length of life and the number of persons treated. The results from a systematic review of the literature suggest that QALY maximisation is descriptively flawed. Rather than being linear in quality and length of life, it would seem that social value diminishes in marginal increments of both. And rather than being neutral to the characteristics of people other than their propensity to generate QALYs, the social value of a health improvement seems to be higher if the person has worse lifetime health prospects and higher if that person has dependents. In addition, there is a desire to reduce inequalities in health. However, there are some uncertainties surrounding the results, particularly in relation to what might be affecting the responses, and there is the need for more studies of the general public that attempt to highlight the relative importance of various key factors.

Age Factors↗
PubMed1996

Placental abruption and its association with hypertension and prolonged rupture of membranes: a methodologic review and meta-analysis.

OBJECTIVE: To conduct a meta-analysis of published studies on placental abruption to examine its incidence, recurrence, and association with hypertensive disorders (chronic hypertension and preeclampsia) and prolonged rupture of membranes (PROM) in pregnancy. DATA SOURCES: We reviewed studies on placental abruption published since 1950, based on a comprehensive literature search using MEDLINE, and by identifying studies cited in the references of published reports. METHODS OF STUDY SELECTION: We identified 54 studies, excluding case reports on placental abruption and studies relating to placenta previa and vaginal bleeding of unknown origin. We also restricted the search to articles published in English. TABULATION, INTEGRATION, AND RESULTS: Studies chosen for the meta-analysis were categorized based on their study design (case-control or cohort), where they were conducted (United States or other countries), source of the data (vital records versus other sources), and magnitude of risk (risk of abruption greater or less than 1.0%). We used both fixed- and random-effects analysis to identify sources of heterogeneity in results among studies. There were striking differences in the incidence of placental abruption between cohort (0.69%) and case-control (0.35%) studies. United States-based studies found a somewhat higher incidence both for cohort (0.81%) and case-control (0.37%) studies compared with studies conducted outside the U.S. (0.60% and 0.26%, respectively). Abruption was more than ten times more common in pregnancies preceded by a pregnancy with abruption. Chronically hypertensive patients were more than three times as likely to develop placental abruption (odds ratio [OR] 3.13, 95% confidence interval [CI] 2.04-4.80) as normotensive patients. The OR for placental abruption was 1.73 (95% CI 1.47-2.04) for patients with preeclampsia. Similarly, women with pregnancies complicated by PROM were more than three times as likely to develop placental abruption (OR 3.05, 95% CI 2.16-4.32). United States-based studies, case-control studies, and studies with an incidence of abruption greater than 1% demonstrated stronger associations between abruption and hypertension and PROM. CONCLUSION: Risk of abruption is strongly associated with chronic hypertension, PROM, and especially abruption in a prior pregnancy, and somewhat more modestly with preeclampsia. The criteria for the diagnosis of placental abruption, hypertensive disorders, and PROM may have introduced variability among the results of these studies. More standardized definitions of these pregnancy complications would improve the comparability of the study results.

Abruptio Placentae↗
PubMed1986

The metric analysis of three-dimensional dendritic tree patterns: a methodological review.

Metric analysis methods used to study neuronal arborizations are reviewed and discussed. The analysis methods considered are those examining the spatial orientation and density of the whole dendritic field of a neuron, the metrics of dendritic segments and the bifurcation angles. General variables indicating the size of the soma and the dendritic field are indicated. In addition, the instrumentation used for providing 3-dimensional data for metric analyses and the shrinkage of Golgi-stained neurons are discussed.

Animals↗
PubMed2006

Outcomes research: a methodologic review.

OBJECTIVES: We explored the history and conceptual trends of outcomes research. METHODS: We described different aspects of this field, after dividing it into conceptually distinct strata. RESULTS: Outcomes research can be divided into macro, meso and micro levels. Each level is further subdivided. Macro-level research targets cost and health care utilization, as well as racial, ethnic and geopolitical population health determinants. Meso-level studies address effectiveness, variability, disease impact, clinical modeling and program evaluation studies. Finally, micro-level studies address all aspects of direct patient-clinician decision-making. CONCLUSIONS: An explosion of outcomes research has occurred in the past decades. Wide access to information technology, data sharing and collaborative efforts between researchers represent some of the ingredients that did and will continue to fuel that growth.

Humans↗
PubMed2006

Risk assessment scales for pressure ulcers: a methodological review.

Much is written about risk-assessment scales (RASs) for pressure ulcers (PU) and their properties demonstrating that they are of limited value. Less is known about the reasons for these limitations and the scope for improvement. This review examines issues such as structure and scoring for the Norton, Waterlow and Braden scales, showing that the equal-weighting technique behind the current RASs is too simplistic and leads to limitations. It concludes that properly trained, experienced nurses should conduct PU risk assessments, whilst more robust data-driven RASs should be developed using the differential weighting scoring method together with advanced statistical techniques.

Data Interpretation, Statistical↗