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PubMed2000

Maximum androgen blockade: a case study report.

The use of maximum androgen blockade (MAB) in advanced prostate cancer remains controversial due to conflicting data from clinical trials. Some of the trials that report no advantage of MAB over monotherapy have been criticized on a number of points, including a lack of statistical power and too short a follow-up period. Three randomized trials, SWOG-INT 0036, EORTC-30853 and the Anandron Study Group Trial, report a survival advantage and a longer time to disease progression with MAB, although only one reaches statistical significance. The widespread use of MAB is controversial on the basis of the available clinical data. It has been suggested that three clinical situations exist for its use in advanced cancer: in symptomatic disease; as neoadjuvant therapy prior to radiotherapy; and for the prevention of flare following the use of luteinizing-hormone-releasing hormone analogues as monotherapy. Case studies are presented in this article involving the use of MAB in these circumstances, as well as its use under other conditions. MAB fits into an algorithm of progressive step-up therapy and by tailoring hormonal therapy to individual patients and their tumours we may improve survival and define further the future role of MAB. Prostate Cancer and Prostatic Diseases (2000) 3, 203-212

Journal Article↗
PubMed1998

A new approach to the problem of multiple comparisons in the genetic dissection of complex traits.

Saturated genetic marker maps are being used to map individual genes affecting quantitative traits. Controlling the "experimentwise" type-I error severely lowers power to detect segregating loci. For preliminary genome scans, we propose controlling the "false discovery rate," that is, the expected proportion of true null hypotheses within the class of rejected null hypotheses. Examples are given based on a granddaughter design analysis of dairy cattle and simulated backcross populations. By controlling the false discovery rate, power to detect true effects is not dependent on the number of tests performed. If no detectable genes are segregating, controlling the false discovery rate is equivalent to controlling the experimentwise error rate. If quantitative loci are segregating in the population, statistical power is increased as compared to control of the experimentwise type-I error. The difference between the two criteria increases with the increase in the number of false null hypotheses. The false discovery rate can be controlled at the same level whether the complete genome or only part of it has been analyzed. Additional levels of contrasts, such as multiple traits or pedigrees, can be handled without the necessity of a proportional decrease in the critical test probability.

Animals↗
PubMed2001

Assessment of underlying etiology and cardiac sympathetic innervation to identify patients at high risk of cardiac death.

UNLABELLED: Cardiac (123)I-labeled metaiodobenzylguanidine (MIBG) activity has significant incremental prognostic value, but the difference between the long-term prognostic value of MIBG imaging for ischemic cardiomyopathies and the long-term prognostic value of MIBG imaging for idiopathic cardiomyopathies is not clear. This study aimed to determine whether assessment of cardiac (123)I-MIBG activities in ischemic and idiopathic cardiomyopathies have equally prognostic values and whether the kinetics are different because of the underlying etiologies. METHODS: After quantitative (123)I-MIBG imaging, 76 ischemic and 56 idiopathic cardiomyopathy patients were prospectively followed up for 54 mo. In addition to conventional parameters, cardiac (123)I-MIBG activity was quantified as a heart-to-mediastinum ratio (H/M) for early and late images and the washout kinetics were calculated using tomographic imaging. The data were compared with those obtained from 16 healthy volunteers. RESULTS: During follow-up, 29 deaths from heart failure, 11 sudden cardiac deaths, 2 deaths from arrhythmia, and 5 deaths from acute myocardial infarction were documented. Multivariate discriminant analysis using the Cox proportional hazards model showed that, in comparison with other variables, late H/M was the most powerful independent predictor of a lethal clinical outcome in ischemic (Wald chi(2) = 18.6502; P = 0.0000) and idiopathic (Wald chi(2) = 5.3394; P = 0.0208) groups. When patients with left ventricular ejection fraction (LVEF) < 40% were considered, late H/M had the greatest statistical power in both groups. Kaplan-Meier analysis showed late H/M to have an identical threshold (1.82) for both groups for identifying patients at risk of cardiac death. Likewise, when analysis was restricted to patients with an LVEF < 40%, the upper cutoff value of late H/M was 1.50 (P = 0.0358; log rank = 4.41) for ischemic patients and 2.02 (P = 0.0050; log rank = 7.86) for idiopathic patients. For patients with an LVEF < 40% and a late H/M less than the identified threshold of late H/M, the annual rate of cardiac death was greatest, 18.2%/y for the ischemic group and 11.9%/y for the idiopathic group. CONCLUSION: Cardiac (123)I-MIBG activity has the most powerful independent long-term prognostic value for both ischemic cardiomyopathy patients and idiopathic cardiomyopathy patients, indicating that both disease processes have common pathophysiologic and prognostic implications of impaired cardiac sympathetic innervation. Although combined testing of cardiac function and (123)I-MIBG activity is most likely to identify patients at increased risk of cardiac death, the underlying etiology of cardiac dysfunction may affect the threshold of (123)I-MIBG activity for the differentiation of high-risk patients.

3-Iodobenzylguanidine↗
PubMed1992

Methodologic issues in using epidemiologic studies of occupational cohorts for cancer risk assessment.

This paper focuses on presenting a review and discussion of the major methodologic issues involved in using epidemiologic studies of occupational groups for assessing human cancer risks. Although animal studies have been most often used for quantitative risk assessment, it is generally recognized that well conducted epidemiologic studies would provide the best basis for estimating human risk. However, there are several features related to the design and analysis of epidemiologic studies which frequently limit their usefulness for quantitating risks. The lack of accurate information on exposure in epidemiologic studies is perhaps the most frequently cited limitation of these studies for risk assessment. However, other features of epidemiologic study design such as statistical power, length of follow-up, selection bias, confounding and effect modification may also limit the inferences that can be drawn from these studies. Furthermore even when the aforementioned limitations are overcome, substantial uncertainty exists concerning the choice of an appropriate statistical (or biologic) model for extrapolation beyond the range of exposures observed in a particular study. An empirical example is provided in which estimates of risk varied by nearly 3 orders of magnitude depending on which functional form of the model was chosen. Modeling of epidemiologic data for QRA should be based upon internal comparisons rather than on modeling Standardized Mortality Ratios (SMRs) when possible. Because of the limitations discussed in this paper, epidemiologic data should not be viewed as a panacea for the problems inherent in using animal bioassay data for QRA.(ABSTRACT TRUNCATED AT 250 WORDS)

Bias↗
PubMed2003

Effectiveness of physiotherapy for lateral epicondylitis: a systematic review.

AIM: To evaluate the available evidence of the effectiveness of physiotherapy for lateral epicondylitis of the elbow. METHOD: Randomised controlled trials (RCTs) identified by a highly sensitive search strategy in six databases in combination with reference checking. Two independent reviewers selected RCTs that included a physiotherapy intervention, patients with lateral epicondylitis, and at least one clinically relevant outcome measure. No language restrictions were made. Methodological quality was independently assessed by two blinded reviewers. A best evidence synthesis, including a quantitative and qualitative analysis, was conducted, weighting the studies with respect to their internal validity, statistical significance, clinical relevance, and statistical power. RESULTS: 23 RCTs were included in the review, evaluating the effects of lasertherapy, ultrasound treatment, electrotherapy, and exercises and mobilisation techniques. Fourteen studies satisfied at least 50% of the internal validity criteria. Except for ultrasound, pooling of data from RCTs was not possible because of insufficient data, or clinical or statistical heterogeneity. The pooled estimate of the treatment effects of two studies on ultrasound compared to placebo ultrasound, showed statistically significant and clinically relevant differences in favour of ultrasound. There is insufficient evidence either to demonstrate benefit or lack of effect of lasertherapy, electrotherapy, exercises and mobilisation techniques for lateral epicondylitis. CONCLUSIONS: Despite the large number of studies, there is still insufficient evidence for most physiotherapy interventions for lateral epicondylitis due to contradicting results, insufficient power, and the low number of studies per intervention. Only for ultrasound, weak evidence for efficacy was found. More better designed, conducted and reported RCTs are needed.

Australia↗
PubMed2007

A spatial scan statistic for ordinal data.

Spatial scan statistics are widely used for count data to detect geographical disease clusters of high or low incidence, mortality or prevalence and to evaluate their statistical significance. Some data are ordinal or continuous in nature, however, so that it is necessary to dichotomize the data to use a traditional scan statistic for count data. There is then a loss of information and the choice of cut-off point is often arbitrary. In this paper, we propose a spatial scan statistic for ordinal data, which allows us to analyse such data incorporating the ordinal structure without making any further assumptions. The test statistic is based on a likelihood ratio test and evaluated using Monte Carlo hypothesis testing. The proposed method is illustrated using prostate cancer grade and stage data from the Maryland Cancer Registry. The statistical power, sensitivity and positive predicted value of the test are examined through a simulation study.

Cluster Analysis↗
PubMedDate not supplied

On combining dose-response data from epidemiological studies by meta-analysis.

Using data from a meta-analysis of the effects of oestrogen replacement therapy on the development of breast cancer, we compared alternative methods for combining dose-response slopes from epidemiological studies. We evaluated issues related both to summarizing data from single studies and to combining results from multiple studies. Findings related to the analysis of individual dose-response studies include: (1) a method of weighing studies that gives greater influence to dose-response slopes that conform to the linear relation of relative risk to duration can lead to large differences in calculated weights as a function of non-linearity; (2) a regression model using a variable-intercept resulted in a mean dose-response slope that increased as much as threefold when compared with the values obtained with a zero-intercept model. When combining results from multiple studies, we found: (1) calculating standard errors of mean dose-response slopes by methods that allow for both among-study and within-study variability (a random-effects type model) gave values different from a method that assumes homogeneity and equal within-study precision (a fixed-effects model); (2) the random-effects model gives mean and standard error results most similar to a bootstrap resampling method as increasing heterogeneity is observed (however, this model could give biased mean estimates compared with the bootstrap method); (3) a components-of-variance model compares favourably with the bootstrap and is easier to apply than the random-effects model. Based on these findings, we recommend the use of methods which incorporate heterogeneity to guard against underestimating the standard error. However, caution is urged because bias in point estimates can occur if extreme heterogeneity is present. Two other observations affect the interpretation of data combined from multiple studies. First, inclusion into a model of quality scores assigned by blinded reviewers had little effect on the mean dose-response slope and its standard error. Second, the number of studies required to achieve desired statistical power, varies with effect size.

Analysis of Variance↗
PubMed1995

Fecal diversion for penetrating colon injuries--still the established treatment.

PURPOSE: An analysis of the existing literature on primary repair of colon injuries was undertaken to determine if there is sufficient evidence that this approach is superior to fecal diversion. METHODS: After a thorough literature search, three prospectively randomized studies comparing primary repair with fecal diversion in the management of colon injuries were identified. A variety of factors were examined, including the number of patients in each study arm, morbidity rates, as well as exclusion criteria. An analysis was performed to determine the number of patients required to establish statistical superiority of one procedure over the other. RESULTS: Pooling of the data contained in the aforementioned reports does not provide sufficient statistical power to support the superiority of primary repair of colon injuries. To demonstrate a 5 percent difference between the two approaches, a prospective, randomized study consisting of 200 patients in each arm is necessary. CONCLUSION: The present literature does not support a statistically valid advantage of primary repair over fecal diversion in the management of traumatic colon injuries.

Colon↗
PubMed2005

Power of in silico QTL mapping from phenotypic, pedigree, and marker data in a hybrid breeding program.

Most quantitative trait locus (QTL) mapping studies in plants have used designed mapping populations. As an alternative to traditional QTL mapping, in silico mapping via a mixed-model approach simultaneously exploits phenotypic, genotypic, and pedigree data already available in breeding programs. The statistical power of this in silico mapping method, however, remains unknown. Our objective was to evaluate the power of in silico mapping via a mixed-model approach in hybrid crops. We used maize (Zea mays L.) as a model species to study, by computer simulation, the influence of number of QTLs (20 or 80), heritability (0.40 or 0.70), number of markers (200 or 400), and sample size (600 or 2,400 hybrids). We found that the average power to detect QTLs ranged from 0.11 to 0.59 for a significance level of alpha=0.01, and from 0.01 to 0.47 for alpha=0.0001. The false discovery rate ranged from 0.22 to 0.74 for alpha=0.01, and from 0.05 to 0.46 for alpha=0.0001. As with designed mapping experiments, a large sample size, high marker density, high heritability, and small number of QTLs led to the highest power for in silico mapping via a mixed-model approach. The power to detect QTLs with large effects was greater than the power to detect QTL with small effects. We conclude that gene discovery in hybrid crops can be initiated by in silico mapping. Finding an acceptable compromise, however, between the power to detect QTL and the proportion of false QTL would be necessary.

Breeding↗
PubMedDate not supplied

Uses of the coefficient of detection and sample size determination.

The coefficient of detection (CD) is said to represent the minimal difference statistically detectable with a t-test at some preselected alpha. Although the CD does not explicitly take statistical power into consideration, it is mathematically and empirically demonstrable that the CD operates at approximately 50% power. The CD, as reported in the Collaborative Behavioral Teratology Study (CBTS), also applies only to hypotheses about the difference between one sample mean and a selected standard value, and, consequently, does not apply to a situation where a difference between two sample means is considered. Therefore, the low one-sample CDs reported in the CBTS cannot be used to approximate sample sizes for purposes of meeting the requirement by the Environmental Protection Agency that a 20% difference between two sample means (e.g., control vs. experimental groups) should be detected with a power of 80% (or 90%) at a 5% certainty level.

Animals↗
PubMed2006

A retrospective study of the midterm outcome of two-bundle anterior cruciate ligament reconstruction using quadrupled semitendinosus tendon in comparison with one-bundle reconstruction.

PURPOSE: The objective of the study was to retrospectively compare the outcome of the first series of a 2-bundle anterior cruciate ligament reconstruction technique using quadrupled semitendinosus tendon with that of a 1-bundle reconstruction technique from 1992 through 1996. TYPE OF STUDY: Case-control study. METHODS: The 1-bundle group consisted of 56 patients with a follow-up period of 24 months or more (average, 46.5 months). The 2-bundle group consisted of 79 patients with a follow-up period of 24 months or more (average, 40.8 months). Manual knee laxity tests, anterior stability with KT-1000 (manual maximum), and knee extension and flexion strength by Cybex were evaluated using an average and standard deviation, and data were categorized according to the International Knee Documentation Committee (IKDC) classification. The Lysholm scale and the subjective recovery scale were also evaluated. RESULTS: A statistically greater number of patients in the 1-bundle group were positive (+ or ++) based on the Lachman test (34% in the 1-bundle group and 13% in the 2-bundle group). The average KT-1000 anterior laxity of 2.7 +/- 2.3 mm in the 1-bundle group was statistically greater than the 1.9 +/- 1.9 mm in the 2-bundle group, with a statistical power between 70% and 80%. The total Lysholm knee scale score was 93 points in both groups, and the subjective recovery score was equivalent, 82% in the 1-bundle group and 86% in the 2-bundle group, respectively. CONCLUSIONS: There was no statistical difference based on the IKDC, Lysholm, and subjective analysis. However, there was a statistical difference in the Lachman test, anterior drawer test, and KT-1000 measurements. LEVEL OF EVIDENCE: Level III.

Adolescent↗
PubMed1997

Differing responses in blood pressure over 24 hours in normotensive women receiving oral or transdermal estrogen replacement therapy.

OBJECTIVE: To examine the effects of oral and transdermal estrogen replacement therapy (ERT) on ambulatory 24-hour blood pressure (BP) recordings. METHODS: In a nonrandomized, prospective study, 90 normotensive, oophorectomized women, ages 30-59 years, underwent ambulatory 24-hour BP measurements at study entry and after 3 and 6 months of either oral (n = 50) or transdermal (n = 40) ERT. RESULTS: In the women receiving transdermal estrogen, we observed a change in mean nighttime systolic BP of -4.2 mmHg (95% confidence interval [CI] -7.7, -0.7; P = .039) after 6 months, treatment. There was a change in mean daytime diastolic BP after 3 months (-3.3 mmHg; 95% CI -5.5, -0.9; P = .016) and 6 months (-4 mmHg; 95% CI-6.8, -1.2; P = .014), and in mean nighttime diastolic BP after 3 months (-3.8 mmHg; 95% CI -6.6, -0.9; P = .027) and 6 months (-4.4 mmHg; 95% CI -7.1, -1.7; P = .005). No significant BP changes were observed in the women taking oral estrogen. Although the statistical power to detect a change of 4 mmHg at the 5% significance level was 90% for diastolic BP, it was weaker for systolic BP (63%) in this group. However, in more than one-third of the women receiving either treatment, a statistically significant increase in BP was observed. CONCLUSIONS: Transdermal ERT was associated with a reduction in mean ambulatory BP, whereas oral treatment did not alter BP. Although the overall effect of estrogen was to lower BP, individual responses were variable, and BP increased in more than one-third of the women on either treatment. Therefore, long-term monitoring of ambulatory measurements may be required.

Administration, Cutaneous↗
PubMed2002

Claims of equivalence in randomized controlled trials of the treatment of bacterial meningitis in children.

OBJECTIVE: To evaluate claims of therapeutic equivalence in studies of the treatment of bacterial meningitis in children. METHODS: We performed a systematic review of randomized controlled trials of antimicrobial therapy for bacterial meningitis in children indexed in MEDLINE and published after 1980 and that claimed equivalency. The sample size of each trial was compared with the minimum sample size needed to rigorously claim equivalence. The primary endpoint was case fatality. RESULTS: Twenty-five studies were identified that met the inclusion criteria. Two of these were specifically designed to test equivalence, and the remaining based claims of equivalence on failed tests of superiority. The majority of these trials (24 of 25) that claimed equivalence had sufficient sample size to exclude a 20% difference in mortality between the tested therapies. Only 3 of the 25 trials could exclude a 10% difference in mortality. CONCLUSION: Few of the trials in this study had sufficient sample size to claim equivalence within 10% of the expected mortality. Proving equivalency is challenging because large sample sizes are often needed to ensure adequate statistical power to rule out clinically important differences between the standard of care and new therapies.

Anti-Bacterial Agents↗
PubMed1995

Mammographic screening for women aged 40 to 49 years: the primary care practitioner's dilemma.

The data from population-based, randomized trials of the mammographic screening of women aged 40 to 49 years are limited by retrospective subgroup analysis, low statistical power, and the use of older mammographic techniques. Nonetheless, meta-analysis involving the most recently reported data from all similarly designed trials shows a 21% mortality reduction in women who have had mammographic screening compared with those in control groups, a statistically significant difference (upper bound of 95% Cl, 0.98). Evidence from modern mammography demonstration projects (which are limited by a lack of control groups and the unavailability of mortality results) also shows that the tumor size, axillary lymph node status, and stage of screening-detected breast cancers in women aged 40 to 49 years indicate that screening is at least as beneficial for these women as it is for those aged 50 to 64 years, for whom mammographic screening is widely accepted. Overall, the evidence suggests that screening will benefit women aged 40 to 49 years, but some argue that the level of proof provided is not rigorous enough to establish the efficacy of screening. In the United States, more than 10,000 deaths per year occur among women who develop breast cancer between the ages of 40 and 49. Thousands of lives are probably lost each year because women are not being screened. We believe that it is much more prudent to endorse mammographic screening now, risking the unlikely subsequent determination that the effort was ineffective, than to withhold screening until it is determined whether "proof" of efficacy will be obtained, risking the loss of so many lives. We urge primary care practitioners to recommend routine mammography for women aged 40 to 49 years.

Adult↗
PubMedDate not supplied

Methodological issues in the analysis of human sperm concentration data.

We examined two methodological issues in the analysis of sperm concentration data using a large database of sperm concentrations in healthy men that were collected at the University of Washington. We showed that the raw data were skewed and that log transformation should be used to assure that the data meet the assumptions underlying most statistical estimation and testing procedures. We also addressed the issue of the great variability in sperm concentrations within a single individual and the necessity and utility of multiple sampling to reduce variance. We conclude that log-transformed data should be used for statistical analysis of sperm concentration and recommend that such analyses be based on the geometric mean of several samples from each subject to reduce variability, increase accuracy of estimation, and improve statistical power. This is particularly important when the objective is to detect small but important differences or subtle effects.

Data Interpretation, Statistical↗
PubMed2003

Endoglin is not a major susceptibility gene for intracranial aneurysm among Japanese.

BACKGROUND AND PURPOSE: A 6-base insertion (6bINS) polymorphism in intron 7 of the endoglin gene (ENG), which codes for a component of the transforming growth factor-beta receptor complex, was reported to be associated with intracranial aneurysm (IA) in a Japanese population. A recent report using a white population could not replicate the association. We tested for this association with high statistical power in our independent Japanese subjects and evaluated the linkage between markers on chromosome 9, which contains ENG, and IA. METHODS: The sample for the linkage study comprised 179 individuals with IA in 85 nuclear families, with 104 possible affected sibpairs. For the association study of the 6bINS polymorphism and 4 single nucleotide polymorphisms (SNPs) in ENG, 172 Japanese patients with IA and 192 control subjects were examined. RESULTS: There was no evidence of linkage in the vicinity of ENG by analysis of affected sibpairs. The allele frequency of the 6bINS polymorphism was 104 of 344 (30.2%) in the total IA group and 122 of 382 (31.9%) in the control group. The statistical difference in allele frequency between the 2 groups was not significant (chi2=0.245, df=1, P=0.620). The power of the present association study was 98.3% at a significance level of 0.05 on the basis of the allele frequencies in the previous study. In addition, no associations between the 4 SNPs in ENG and IA were detected. CONCLUSIONS: We provide evidence that there is no association between the 6bINS polymorphism or 4 SNPs in ENG and IA and that there is no linkage between the ENG locus and IA, indicating that ENG is not a major susceptibility gene for IA in Japanese.

Antigens, CD↗
PubMed2003

Insulin glargine: a systematic review of a long-acting insulin analogue.

BACKGROUND: Insulin glargine is the first long-acting basal insulin analogue indicated for subcutaneous administration once daily at bedtime in adults with type 1 or type 2 diabetes mellitus and pediatric patients aged > or = 6 years with type 1 diabetes. It differs in structure from native human insulin by 3 amino acids, a structural modification that provides a delayed onset of action and a constant, peakless effect that has a duration of at least 24 hours. OBJECTIVE: The goal of this article was to help determine the current place in therapy of insulin glargine by reviewing all available efficacy and tolerability data published since its introduction onto the market. METHODS: Relevant English-language articles were identified through searches of MEDLINE, PubMed, and EMBASE from 1966 to October 2002 and PREMEDLINE for November 2002. The search terms used were insulin, analogs, analogues, diabetes mellitus, glargine, HOE901, HOE-901, efficacy, safety, comparative study, treatment outcome, and case report. The reference lists of the identified articles were searched for additional relevant publications. Pharmacokinetic and pharmacodynamic data were reviewed and summarized. All large clinical trials (> or = 100 patients) evaluating the efficacy and tolerability of insulin glargine in patients with type 1 or type 2 diabetes were included in the review. Studies were compared in terms of their designs, primary and secondary efficacy parameters (glycosylated hemoglobin [HbA(1c)], fasting plasma glucose [FPG] and/or fasting blood glucose [FBG] level, incidence of hypoglycemia), and tolerability assessments. RESULTS: Fourteen trials met the criteria for inclusion in this review, 7 of them published only in abstract form. All were multicenter, randomized, open-label, parallel-group trials conducted in Europe or the United States, and ranged in duration from 4 to 52 weeks. They compared insulin glargine with neutral protamine Hagedorn (NPH) insulin given once or twice daily in >5000 patients with type 1 or type 2 diabetes, or in insulin-naive patients with type 2 diabetes that was poorly controlled by oral antidiabetic agents. Insulin doses were individually titrated to achieve a target FBG level < or =120 mg/dL (6.7 mmol/L). The studies were typically statistically underpowered to detect a significant difference in HbA(1c) between treatment groups; only 3 trials were of an adequate size to have 90% statistical power to detect a mean 0.5% difference in HbA(1c). Furthermore, analysis of the data from these trials was associated with a number of methodologic problems relating to inconsistencies in reporting. Given these limitations, the available data suggest that insulin glargine treatment produces statistically significant reductions in FPG or FBG levels at end point both compared with baseline and compared with NPH insulin (P < 0.001) without achieving overall significant improvements in HbA(1c) values. However, a recent abstract of a small 52-week trial in patients with type 1 diabetes reported a 0.4% additional decrease in HbA(1c) with insulin glargine treatment compared with NPH insulin. Patients have reported greater treatment satisfaction with insulin glargine compared with NPH insulin. The findings varied regarding weight gain, overall incidence of hypoglycemia, and incidence of nocturnal hypoglycemia. Currently, the cost of insulin glargine is twice that of NPH insulin on a per-unit basis. CONCLUSIONS: As a basal insulin replacement, insulin glargine administered once daily demonstrates a steady time-action profile over 24 hours without a pronounced peak. Based on the evidence from published clinical trials, insulin glargine appears to have equal clinical efficacy to NPH insulin, produces similar reductions in HbA(1c), and is associated with lower FPG and FBG levels and a consistent and significant reduction in the incidence of nocturnal hypoglycemia in patients with type 2 diabetes.

Clinical Trials as Topic↗
PubMed1992

Pharmacologic management of refractory depression.

OBJECTIVE: To review published clinical trials of the pharmacologic management of refractory depression. DATA SOURCES: MEDLINE was searched for relevant articles published from 1983 to 1990. The bibliographies of review articles were searched for additional references. Studies of nonpharmacologic treatments, such as electroconvulsive therapy, were not included. STUDY SELECTION: Eleven studies were found that did not contain obvious digressions from several methodologic assessment criteria (adapted from the McMaster guidelines for the evaluation of clinical trials). Further scrutiny by a nonblind reviewer resulted in the selection of four reports that were considered acceptable. An assessment by a second reviewer, blind as to author, results and journal name, confirmed this judgement. DATA EXTRACTION: Data describing response to the treatments were extracted by a single (nonblind) reviewer. Post-hoc power estimates and 95% confidence intervals were calculated whenever possible. DATA SYNTHESIS: The efficacy of augmenting an antidepressant regimen with lithium carbonate, triiodothyronine or reserpine was not supported by findings from the clinical trials reviewed. However, many trials with negative results lacked adequate statistical power to exclude the possibility of the drug's efficacy. The use of a monoamine oxidase inhibitor was supported by the one study that met the review's methodologic criteria. However, this study was not conducted under double-blind conditions. CONCLUSION: The generally recommended strategies for the pharmacologic treatment of refractory depression are not supported by methodologically sound studies.

Antidepressive Agents↗