Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “sensitivity analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 541 records · Page 30Linked to original sources
PubMed1999

Breast cancer screening by mammography in Norway. Is it cost-effective?

BACKGROUND: Mammography screening is a promising method for improving prognosis in breast cancer. PATIENTS AND METHODS: In this economic analysis, data from the Norwegian Mammography Project (NMP), the National Health Administration (NMA) and the Norwegian Medical Association (NMA) were employed in a model for cost-effectiveness analysis. According to the annual report of the NMP for 1996, 60,147 women aged 50-69 years had been invited to a two-yearly mammographic screening programme 46,329 (77%) had been screened and 337 (0.7%) breast cancers had been revealed. The use of breast conserving surgery (BCS) was in this study estimated raised by 17% due to screening, the breast cancer mortality decreased by 30% and the number of life years saved per prevented breast cancer death was calculated 15 years. RESULTS: The cost per woman screened was calculated 75.4 Pounds, the cost per cancer detected 10.365 Pounds and the cost per life year (LY) saved 8.561 Pounds. A raised frequency of BCS, diagnosis and adjuvant chemotherapy brought two years forward, follow-up costs and costs/savings due to prevented breast cancer deaths were all included in the analysis. A sensitivity analysis documented mammography screening cost-effective in Norway when four to nine years are gained per prevented breast cancer death. CONCLUSION: Mammography screening in Norway looks cost-effective. Time has come to encourage national screening programmes.

Aged↗
PubMed2002

Systematic review of long term effects of advice to reduce dietary salt in adults.

OBJECTIVE: To assess the long term effects of advice to restrict dietary sodium in adults with and without hypertension. DESIGN: Systematic review and meta-analysis of randomised controlled trials. DATA SOURCES: Cochrane library, Medline, Embase, and bibliographies. STUDY SELECTION: Unconfounded randomised trials that aimed to reduce sodium intake in healthy adults over at least 6 months. Inclusion decisions, validity and data extraction were duplicated. Random effects meta-analysis, subgrouping, sensitivity analysis, and meta-regression were performed. OUTCOMES: Mortality, cardiovascular events, blood pressure, urinary sodium excretion, quality of life, and use of antihypertensive drugs. RESULTS: Three trials in normotensive people (n=2326), five trials in those with untreated hypertension (n=387), and three trials in people being treated for hypertension (n=801) were included, with follow up from six months to seven years. The large high quality (and therefore most informative) studies used intensive behavioural interventions. Deaths and cardiovascular events were inconsistently defined and reported. There were 17 deaths, equally distributed between intervention and control groups. Systolic and diastolic blood pressures were reduced (systolic by 1.1 mm Hg, 95% confidence interval 1.8 to 0.4 mm Hg; diastolic by 0.6 mm Hg, 1.5 to -0.3 mm Hg) at 13 to 60 months, as was urinary 24 hour sodium excretion (by 35.5 mmol/24 hours, 47.2 to 23.9). Degree of reduction in sodium intake and change in blood pressure were not related. CONCLUSIONS: Intensive interventions, unsuited to primary care or population prevention programmes, provide only small reductions in blood pressure and sodium excretion, and effects on deaths and cardiovascular events are unclear. Advice to reduce sodium intake may help people on antihypertensive drugs to stop their medication while maintaining good blood pressure control.

Adolescent↗
PubMed1996

Integrated mathematical model to assess beta-cell activity during the oral glucose test.

A model describing beta-cell secretion during an oral glucose tolerance test (OGTT) is introduced. The aim was to quantify beta-cell activity in different pathologies by analyzing peripheral concentration data of insulin, C-peptide, and islet amyloid polypeptide (IAPP). Insulin appearance in periphery is given by the fraction of C-peptide secretion, CPS(t), which accounts for liver degradation. A novelty of this study is the inclusion of IAPP delivery assumed proportional to CPS(t). Although IAPP fractional clearance is estimated in every subject, the clearances of insulin and C-peptide are assigned from a wide set of previous independent studies. Sensitivity analysis was performed to quantify the "error" in the estimated variables due to these assignments. All parameters relating to beta-cell secretion increased in the glucose-intolerant states [integrated CPS(t)=56 +/- 8 nmol/l in 180 min vs. 32 +/- 3 of controls, P<0.05; total IAPP delivery= 83 +/- 21 pmol/l in 180 min vs. 41 +/- 6, P<0.05]. Elevated plasma IAPP concentration of the patients was due to augmented secretion since IAPP clearance was found to be even slightly greater than in controls, (0.053 +/- 0.011 vs. 0.034 +/- 0.004 min-1) and markedly lower than that of insulin (0.14 +/- 0.02, P<0.01). In conclusion, the model introduced here allows the characterization of beta-cell secretory parameters during a simple test such as OGTT.

Amyloid↗
PubMed1996

Adenosine kinetics in canine coronary circulation.

Adenosine kinetics in the coronary circulation were investigated in anesthetized closed-chest dogs by analysis of multiple-indicator dilution experiments. During simultaneous intracoronary bolus injections of 125I-labeled albumin, [14C]sucrose, and [3H]adenosine, dilution curves were measured by automated sampling of coronary venous blood, using high-performance liquid chromatography and isotope detection techniques. Under control conditions, only 1% of the injected [3H]adenosine was detected in coronary venous samples, compared with the reference tracer, [14C]sucrose, and the peak of the adenosine dilution curve preceded those of the reference tracers by 2-4 s. Optimized model fits to the control adenosine curves required the combination of high ratios of the capillary endothelial cell membrane permeability-surface area product to flow (5.3) and endothelial cell consumption capacity to flow (23), in addition to a broad heterogeneity of flow. Dilution curves were measured under control conditions and during increased coronary flow (nitroglycerin), inhibition of the enzyme adenosine kinase (iodotubercidin), and blockade of membrane adenosine transport (dipyridamole). Reliability of the parameter estimates was confirmed using residual analysis, sensitivity function analysis, and Monte Carlo simulation techniques. Accuracy of the model was confirmed in separate experiments in which nontracer adenosine was infused into the coronary artery and the model prediction of coronary venous adenosine concentrations was compared with measured values. Using published measurements of coronary blood flow and arterial and coronary venous plasma adenosine concentrations in open-chest dogs, the estimated in vivo interstitial adenosine concentration is 100-220 nM.

Adenosine↗
PubMedDate not supplied

Surgical decisions for early stage, non-small cell lung cancer: which racially sensitive perceptions of cancer are likely to explain racial variation in surgery?

OBJECTIVES: Twenty-three percent of white and 36% of African American patients who suffer from early stage non-small cell lung cancer do not undergo potentially curative surgery A simple decision model is presented to probe for elements of surgical decision making that could explain decisions against lung cancer surgery and racial variation in these decisions. METHODS: A survey of 181 diverse individuals to measure health utility scores for conditions relevant to lung cancer surgery was performed. These scores were inserted into a simple model that calculates quality-adjusted survival related to decisions for and against cancer surgery RESULTS: The health utility score (HUS) for progressive lung cancer, as determined by a survey using the standard gamble approach, is nearly twice as high in African Americans as whites (0.32 v. 0.18). However, in a model incorporating African American utility data, lung cancer surgery remains heavily favored compared to the no-surgery decision (2.32 v. 0.48 quality-adjusted life years). Sensitivity analysis shows that factors that lead to a belief of cancer "cure" in the absence of surgical intervention are much more important than variations of HUS in directing model results away from surgery. CONCLUSION: This analysis illustrates that racial differences in quality-of-life ratings of progressive lung cancer as measured by HUS exist but may not explain decisions against surgery as much as other elements of patient care.

Black or African American↗
PubMed1996

A cost-effectiveness analysis of typhoid fever vaccines in US military personnel.

Typhoid fever has been a problem for military personnel throughout history. A cost-effectiveness analysis of typhoid fever vaccines from the perspective of the US military was performed. Currently 3 vaccine preparations are available in the US: an oral live Type 21A whole cell vaccine; a single-dose parenteral, cell subunit vaccine; and a 2-dose parenteral heat-phenol killed, whole cell vaccine. This analysis assumed all vaccinees were US military personnel. Two pharmacoeconomic models were developed, one for personnel who have not yet been deployed, and the other for personnel who are deployed to an area endemic for typhoid fever. Drug acquisition, administration, adverse effect and lost work costs, as well as the costs associated with typhoid fever, were included in this analysis. Unique military issues, typhoid fever attack rates, vaccine efficacy, and compliance with each vaccine's dosage regimen were included in this analysis. A sensitivity analysis was performed to test the robustness of the models. Typhoid fever immunisation is not cost-effective for US military personnel unless they are considered imminently deployable or are deployed. The most cost-effective vaccine for US military personnel is the single-dose, cell subunit parenteral vaccine.

Cost-Benefit Analysis↗
PubMed1987

Three-channel Lissajous trajectories of auditory brainstem-evoked potentials in patients with neurological lesions affecting the brainstem: preliminary impressions.

Three-channel Lissajous trajectories (3CLT), as well as vertex-mastoid records of auditory brainstem-evoked potentials (ABEP) were obtained from 12 patients with neurological lesions localized to the auditory nerve, the medulla, the pons, the pons and midbrain and the midbrain. Patients selected had well-localized lesions at the levels of the presumed generators of ABEP (10 patients), as well as below (1 patient) and above (1 patient) those levels. The 3CLT measures used were trajectory amplitude, peak latency and amplitude, planar segment number, apex latency, duration, orientation in voltage space, as well as size and shape. Latencies and amplitudes of vertex-positive peaks I-V, as well as interpeak latency differences, were determined. Vertex-mastoid ABEP and 3CLT were compared in terms of their sensitivity to the existence of a lesion, the accuracy of lesion localization as well as their specificity to the lesion. 3CLT had an advantage in all three comparisons, with the most prominent advantage in specificity, which was over twice as high as that of single-channel ABEP. The results of this preliminary study indicate that 3CLT affords a sensitive analysis of ABEP, which is superior to single-channel analysis in sensitivity, accuracy and specificity. These results also indicate that the 'contralateral effect' of peak V latency prolongation in cerebellopontine angle tumors may be related to anatomical changes of its generators' orientation, rather than slowed conduction along the upper brainstem.

Brain Diseases↗
PubMed2004

[Current situation and some intending problems of landscape spatial dynamic model].

Along with the rapid development of remote sensing, geographic information system, computer and other supporting technologies, model approach has become the major method of landscape dynamic study. Based on literature review, this paper analyzed the current situation and some intending problems of the development of landscape spatial dynamic model. Three kinds of models, i. e., stochastic landscape model, neighborhood rule model and landscape process model (including percolation model, individual-based landscape model and spatial ecosystem model) were mainly introduced, and their development status, existing problems and related improvement work were analyzed. The development of model test technologies, such as verification analysis, validation analysis, and sensitivity analysis, were also analyzed. Finally, this paper summed up six major problems that should be dealt with in the future development of the landscape spatial dynamic models. These problems included model arithmetic optimization, scale conversion, model complication and predigesting, model test and assessment, bringing forward of general model, and integration of the traditional model with social-economic factors.

Algorithms↗
PubMed2005

Cost-effectiveness of single-level anterior cervical discectomy and fusion for cervical spondylosis.

STUDY DESIGN: Cost-effectiveness analysis with retrospective cost analysis and literature review. OBJECTIVE: To determine the relative cost-effectiveness of anterior cervical discectomy and fusion (ACDF) with autograft, allograft, and allograft with plating for single-level anterior cervical spondylosis. SUMMARY OF BACKGROUND DATA: There are several accepted methods of surgically treating single-level cervical spondylosis anteriorly. No study has clearly demonstrated the superiority of one method over the alternatives. The techniques may differ in their operative risks and resource use, perioperative complications, short-term outcome, and long-term outcome and complications. Formal cost-effectiveness analysis (CEA) provides a structure for analyzing many variables and comparing different treatment outcomes. Sensitivity analysis is used to test the robustness of the model and to determine variables that have significant effects on the results. Future areas of research and refinements of the CEA model can be developed from these findings. METHODS: A retrospective review of hospital charges was performed for 78 patients who underwent single-level ACDF with allograft alone or ACDF with allograft and plating (ACDFP). The charges were converted to estimated costs for fiscal year 2000 using the ratio of costs to charges method. A CEA model was developed consisting of a decision-analysis model for the first year postsurgery and a Markov model for the next 4 years after surgery. Probabilities and outcome utilities were estimated from the literature. Outcome was measured in quality-adjusted life years (QALYs), and incremental CEA was performed. Several variables were tested in one-way sensitivity analysis. RESULTS: Compared with ACDF with autograft, ACDF with allograft offered an improvement in quality of life at a cost of 496 dollars per QALY. ACDFP provided additional gains in quality of life compared with ACDF with allograft at a cost of 32,560 dollars per QALY in the base case analysis. In sensitivity analysis, these estimates varied between 417 dollars and 741 dollars per QALY and between 19,090 dollars per QALY and domination of ACDFP by ACDF with allograft, respectively. The results were most sensitive to assumptions regarding differences in the length of the postoperative recovery period. CONCLUSIONS: ACDF with allograft offers a benefit relative to ACDF with autograft at a cost of 496 dollars per QALY. ACDFP has a benefit relative to ACDF with allograft at an approximate cost of 32,560 dollars per QALY. CEA provides a method for comparing the benefits and risks of these three procedures. Further research needs to be performed regarding these procedures, particularly examining the postoperative recovery period.

Bone Plates↗
PubMed1982

Population analysis of sensitivity to ampicillin and carbenicillin in Eschericia coli and Enterobacter cloacae.

Population analysis of sensitivity to ampicillin (A) and carbenicillin (Ca) was carried out with four strains of E. coli and five strains of Enterobacter cloacae. The two A-sensitive/Ca-sensitive (A-s/Ca-s) E. coli strains were homogeneous as regards A-sensitivity. From the A-resistant/Ca-s (A-r/Ca-s) E. coli strains, it was possible to select A-r/Ca-r mutants. Mutation frequency approx. 10-7.5. When the inoculum of A-s/Ca-s E. coli was raised, it was possible to select A-r/Ca-s/cephalothin-r variants with a frequency of approx. 10-9.7. In this laboratory 5% (10-1.3) of the received E. coli strains are A-r/Ca-s. These strains might consequently be mutants of the usual A-s/Ca-s E. coli, selected in an ampicillin environment. The two A-s/Ca-s E. cloacae strains developed mutants highly resistant to A, thereby differing from the A-s/Ca-s E. coli strains. The mutation frequency was approx. 10-7.2. Likewise it was possible to select A-r/Ca-r E. cloacae strains from the usual A-r/Ca-s ones. Mutation rate approx. 10-6.8.

Ampicillin↗
PubMed1993

A computer program for non-parametric receiver operating characteristic analysis.

Sensitivity and specificity are key measures of the performance of a given test in detecting a given disorder. For tests yielding numerical scores, sensitivity and specificity usually vary inversely over the range of theoretically possible cutoff scores, complicating the task of quantifying and comparing the diagnostic accuracy of tests. Receiver Operating Characteristic analysis (ROC) approaches this problem by plotting the curve of sensitivity versus 1-specificity for all possible cutoff scores of the test. The area under the ROC curve (AUC) can be used to describe the diagnostic accuracy of the test. Parametric and non-parametric methods exist that allow the calculation of the AUC and the comparison of tests. A disadvantage of parametric formulations is the assumption of a normal or Gaussian distribution of test scores. The present article presents a computer program that utilizes non-parametric formulations that do not require the normal distribution of test scores. The program calculates the sensitivity and specificity of a test at all possible cutoff scores, plots the ROC curve, calculates the AUC, its standard error and 95% confidence limits, and allows the comparison of tests on independent and correlated samples.

Confidence Intervals↗
PubMed2001

Comparison of two diagnostic algorithms for regular broad complex tachycardia by decision theory analysis.

Sensitivity and specificity are two inversely related properties of a diagnostic test and it is often practically infeasible to secure a high value for both simultaneously. Decision theory analysis shows that the utility of a diagnostic test depends not only on its sensitivity and specificity but also on the prevalence of the intended target disorder: when prevalence is low, a high specificity is more important than a high sensitivity, whereas when prevalence is high, a high sensitivity is more important than a high specificity. The significance of this principle is illustrated by two popular algorithms for the electrocardiographic diagnosis of regular broad complex tachycardia (BCT), of which the two main differential diagnoses are ventricular tachycardia (VT) and supraventricular tachycardia with aberrant conduction (SVTAG). Brugada et al. focused on criteria highly specific for VT and used them to build a four-step algorithm. In contrast, Griffith et al. first selected criteria highly sensitive for VT and then criteria highly specific for VT to build a simple two-step algorithm. It can be objectively demonstrated that the Griffith algorithm is more efficient and effective than the Brugada algorithm in terms of clinching the final diagnosis and improving overall diagnostic accuracy. The main reason for this is that VT is more common than SVTAC as the cause of regular BCT, and the Griffith algorithm adhered to the aforementioned principle governing the choice between sensitivity and specificity according to prevalence in its design. The Griffith algorithm also embodies an additional important principle, namely, it is easier and more efficient to choose alternatively between criteria highly specific and highly sensitive for the intended target disorder than concentrating on just one or the other in designing a multiple-step sequential diagnostic algorithm.

Algorithms↗
PubMed2001

Combined chemotherapy and radiotherapy (without surgery) compared with radiotherapy alone in localized carcinoma of the esophagus.

BACKGROUND: Esophageal carcinoma can be managed primarily with either a surgical or radiotherapeutic (non surgical) approach. Strategies to improve the outcome of either modality alone include the use of combined modalities. Combination chemotherapy radiotherapy is one approach that has been explored over the years with increasing application in clinical practice especially in North America. OBJECTIVES: To evaluate the effectiveness of combined chemotherapy and radiotherapy versus radiotherapy alone in the outcome of patients with localized esophageal carcinoma. Outcomes of interest include overall survival, cause specific survival, local recurrence, dysphagia relief, quality of life, acute and chronic toxicities. SEARCH STRATEGY: The Cochrane strategy for identifying randomized trials was combined with MeSH headings including esophageal neoplasms, radiotherapy, chemotherapy combined modality, drug therapy combination. Medline, Cancerlit and Embase were searched using this strategy. In addition, the Cochrane library was also searched. References from relevant articles and personal files were included. SELECTION CRITERIA: Randomized controlled trials in patients with localized esophageal cancer, with one arm employing radiotherapy alone, and one arm employing combination radiotherapy chemotherapy were included. Studies comparing non chemotherapy agents such as pure radiotherapy sensitisers, immunostimulants, planned esophagectomy, were excluded. DATA COLLECTION AND ANALYSIS: Data were extracted by two independent reviewers, and the trial quality was assessed using both the Jadad scoring and Detsky checklist. Sensitivity analysis was planned to explore sources of heterogeneity where heterogeneity existed. The factors hypothesized a priori included combination versus sequential treatment, quality of study, biological effective radiotherapy dose (i.e. Radiotherapy dose) cisplatin versus non cisplatin containing trials, and 5FU versus non 5FU containing trials. Odds Ratio (OR) and 95% confidence limits were used to assess the significance of the difference between the treatment arms. Absolute risk difference and number needed to treat (NNT) were used to express the magnitude of difference where appropriate. MAIN RESULTS: Thirteen randomized trials were included in the analysis. There were eight concomitant and five sequential radiotherapy and chemotherapy (RTCT) studies. The studies were analyzed separately due to observed heterogeneity across all the studies and biological considerations. Concomitant RTCT provided significant overall reduction in mortality at 1 and 2 years. The mortality in the control arms was 67% and 86% respectively. Combined RTCT provided an absolute reduction of mortality by 9% (95% CI 2-17%) and 8% (95% CI 1-17%) respectively. Expressed as NNT, this is 11 and 10 respectively. At longer follow up, the results were heterogeneous, cautioning against pooling of the data. There was a reduction in the overall local recurrence rate. The local recurrence rate for the control arms was in the order of 69%. Combined RTCT provided an absolute reduction of local recurrence rate of 5% (95% CI 4-26%) with a NNT of 7. There was significant increase of severe and life threatening toxicities with a NNH of 6, with this approach. With the sensitivity analysis, there was a suggestion that cisplatin based and 5FU based chemotherapy studies were reasonable regimens to employ when using this strategy. The results from the sequential RTCT studies were heterogeneous and could not be pooled. Factors hypothesized a priori did not identify any single source that could account for a significant component of the heterogeneity. Examining the results individually, there was no data to support clinical benefit. This approach was also accompanied by significant toxicities. REVIEWER'S CONCLUSIONS: When a non-operative approach is selected, then concomitant RTCT is superior to the RT alone. This approach is accompanied by significant toxicities. In patients who are in good general condition, and the risk benefit has been thoroughly discussed with the patient, concomitant RTCT should be considered for the management of esophageal cancer compared with radiotherapy alone.

Combined Modality Therapy↗
PubMed2003

Mississippi mud no more: cost-effectiveness of pharmacokinetic dosage adjustment of vancomycin to prevent nephrotoxicity.

OBJECTIVE: To determine the cost-effectiveness of pharmacokinetic dosage adjustment of vancomycin to prevent nephrotoxicity. An analysis was performed for subpopulations of patients receiving nephrotoxic agents (aminoglycosides, amphotericin, and acyclovir), those in the intensive care unit, and those on the oncology service. METHODS: Decision analysis was used to model the cost-effectiveness of pharmacokinetic dosage adjustment of vancomycin. The reference case was determined, in part, by a retrospective review of 200 patients randomly selected from our clinical pharmacology consultation service. Patients were aged 18 years or older and had received intravenous vancomycin for at least 48 hours, with at least two--one peak and one trough--vancomycin serum concentrations obtained during therapy. Results of published clinical trials were used to determine the probability of vancomycin-induced nephrotoxicity. RESULTS: The mean cost of treating nephrotoxicity was 11,233 dollars at our institution. The mean cost for all patients was 25,166 dollars (sensitivity analysis 15,000-27,500 dollars)/nephrotoxic episode prevented. The subgroup analysis revealed a cost of 8,363 dollars (sensitivity analysis 4,368-10,500 dollars)/nephrotoxic episode prevented in intensive care patients, 5,000 dollars (sensitivity analysis 1,687-13,250 dollars ) in oncology patients, and a dominant strategy showing a cost savings of 5,564 dollars (sensitivity analysis 2,724-12,428 dollars) in those receiving concomitant nephrotoxins. CONCLUSION: Although pharmacokinetic monitoring and dosage adjustment are effective methods for reducing the toxicity of many drugs, controversy exists regarding the necessity of such monitoring with vancomycin. Evaluation by decision analysis over a range of assumptions, varying probabilities, and costs reveals that pharmacokinetic monitoring and vancomycin dosage adjustment to prevent nephrotoxicity are not cost-effective for all patients. However, such dosage adjustment demonstrates cost-effectiveness for patients receiving concomitant nephrotoxins, intensive care patients, and probably oncology patients.

Adult↗
PubMedDate not supplied

[Nifedipine and coronary insufficiency: reasons for controversy].

Meta-analyses of Furberg's original data (after correction of two minor errors) were performed using six different methods. Only three of them gave significant results at p < 0.05. The sensitivity analysis showed that taking into account some of the criticisms applied to the original meta-analysis did not change the results. When all the criticisms were considered together, the 95 per cent confidence interval of the odds ratio for mortality was [0.96; 1.31] instead of [1.06; 1.37] originally (p = 0.14 and p = 0.03 respectively), and the dose excess mortality relationship stressed by Furberg disappeared. When the selection of the studies to be entered in a meta-analysis is not straightforward, a sensitivity analysis should be performed.

Angina Pectoris↗
PubMed2002

Intravenous chemotherapy for resected gastric cancer: meta-analysis of randomized controlled trials.

AIM: To assess the safety and efficacy of different intravenous chemotherapeutic regimens in patients with gastric carcinomas who had undergone gastrectomy. METHODS: A meta-analysis of all the relevant randomized controlled trials (RCTs) was performed. Language was restricted to Chinese and English. RCTs were identified from Medline and Embase (1980-2001/4), and Chinese Bio-medicine Database (1990-2001/1). Literature references were checked at the same time. We included randomized and quasi-randomized trials comparing the efficacy of intravenous chemotherapy after gastrectomy with that of surgery alone in patients with confirmed gastric carcinomas who had undergone gastrectomy. Selection criteria were: randomized or quasi-randomized trials with following-up results; Trials could be double-blind, single-blind or not blind; Chemotherapy groups were given intravenous chemotherapy after gastrectomy without neo-adjuvant chemotherapy, intraperitoneal hyperthermic perfusion, radiotherapy or chemoimmunotherapy; Controlled group included those receiving gastrectomy alone. The following data were extracted: the number of survival and death by the end of the follow-up; the different agents and doses of the intravenous chemotherapy; the baseline of the chemotherapy group and the controlled arm; the serious adverse events; the statistical consideration; cost-effectiveness analysis. The statistical analysis was performed by RevMan4.1 software which was provided by the Cochrane Collaboration. A P value of <0.05 was considered statistically significant. Meta-analysis was done with random effects model. Heterogeneity was checked by chi-square test. Sensitivity analysis was performed by excluding the trials in which Jadad-scale was only 1 score. The result was expressed with odds ratio (OR) for the categorical variable. RESULTS: Fourteen trials involving 4543 patients were included. Meta-analysis was done with random effects model. Heterogeneity and sensitivity analysis were performed also. The effect of intravenous chemotherapy after gastrectomy was better than surgery alone (odds ratio 0.56, 95 %CI 0.40-0.79). There was a significant difference between the two groups by u-test (P=0.0008). Sensitivity analysis revealed the same difference (odds ratio 0.81, 95 % CI 0.70-0.94). Of fourteen trials, only three studies were of high quality according to the Jadad-scale (with three score). There was one meta-analysis trial and the others, about ten trials, were of low quality. There was no trial which mentioned sample-size calculation, allocation concealment, intention-to-treat analysis. Most of the trials didn't describe the blind-procedure. There were five trials which detailed the side-effects according to the toxicity grade by WHO standard. The side-effects halting treatment were haematologic and biochemical toxicity, debilitating nausea and vomiting. There were two patients died of chemotherapy toxicity. CONCLUSION: Based on the review, intravenous chemotherapy after gastrectomy may have positive treatment effect on gastric cancer. However, the evidence is not strong because of the general low methodologic quality of the RCTs. Therefore, we can't make the conclusion that intravenous chemotherapy after gastrectomy may have better treatment effect on gastric cancer than that of surgery alone. Rigorously designed, randomised, double-blind, placebo-controlled trials are required.

Antineoplastic Agents↗
PubMed2004

A probabilistic and interactive decision-analysis system for unruptured intracranial aneurysms.

OBJECT: The goal in this study was to develop an interactive, probabilistic decision-analysis system for clinical use in the decision to treat or observe unruptured intracranial aneurysms. Further goals were to enable users of the system to adapt decision-analysis methods to individual patients and to provide a tool for interactive sensitivity analysis. METHODS: A computer program was designed to model the outcomes of treatment and observation of unruptured aneurysms. The user supplies probabilistic estimates of key parameters relating to a specific patient and nominates discount rate and quality of life adjustments. The program uses Monte Carlo discrete-event simulation methods to derive probability estimates of the outcomes of treatment and observation. Results are expressed as summary statistics and graphs. Discounted quality-adjusted life years are graphed using survival methods. Hierarchical simulations are used to enable investigators to perform probabilistic sensitivity analysis for one or multiple parameters simultaneously. The results of sensitivity analysis are expressed in graphs and as the expected value of perfect information. The system can be distributed and updated using the Internet. CONCLUSIONS: Further research is required into the benefits of clinical application of this system. Further research is also required into the optimum level of complexity of the model, into the user interface, and into how clinicians and patients are likely to interpret results. The system is easily adaptable to a range of medical decision analyses.

Confidence Intervals↗