Meta‐analysis combining parallel and cross‐over clinical trials. I: Continuous outcomes

Curtin, François; Altman, Douglas G.; Elbourne, Diana

doi:10.1002/sim.1205

Cited by 192 publications

(104 citation statements)

References 22 publications

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“…We tried to incorporate the two different study designs used (crossover and parallel) into the meta-analysis [21,22]. One of the prerequisites for using a crossover study is that the mean difference (or the difference between means) of the treatments is available.…”

Section: Methodsmentioning

confidence: 99%

Meta-analysis of short-acting insulin analogues in adult patients with type 1 diabetes: continuous subcutaneous insulin infusion versus injection therapy

Siebenhofer¹,

Plank²,

Berghold

et al. 2004

Diabetologia

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Aims/hypothesis. This study aimed to compare the effect of treatment with short-acting insulin (SAI) analogues versus structurally unchanged short-acting insulin (regular insulin) on glycaemic control and on the risk of hypoglycaemic episodes in type 1 diabetic patients using different insulin treatment strategies. Methods. We performed a meta-analysis of 27 randomised controlled trials that compared the effect of SAI analogues with regular insulin in patients with type 1 diabetes mellitus. The treatments were administered either via continuous subcutaneous insulin infusion (CSII) or by conventional intensified insulin therapy (IIT) with short-acting insulin injections before meals and basal insulin administered once or twice daily in most cases. Results. HbA 1 c levels were reported for 20 studies. For studies using CSII, the weighted mean difference between values obtained using SAI analogues and regular insulin was −0.19% (95% CI: −0.27 to − 0.12), whereas the corresponding value for injection studies was −0.08% (95% CI: −0.15 to −0.02). For the analysis of overall hypoglycaemia, we used the results from nine studies that reported the mean frequency of hypoglycaemic episodes per patient per month. For studies using CSII, the standardised mean difference between SAI analogues and regular insulin was −0.07 (95% CI: −0.43 to 0.28), whereas for IIT studies the corresponding value was −0.04 (95% CI: −0.24 to 0.16). Conclusions/interpretation. Taking into consideration the low quality of the trials included, we can conclude that use of a short-acting insulin analogue in CSII therapy provides a small, but statistically significant improvement in glycaemic control compared with regular insulin. An even smaller effect was obtained with the use of ITT. The rate of overall hypoglycaemic episodes was not significantly reduced with short-acting insulin analogues in either injection regimen.

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Section: Methodsmentioning

confidence: 99%

Meta-analysis of short-acting insulin analogues in adult patients with type 1 diabetes: continuous subcutaneous insulin infusion versus injection therapy

Siebenhofer¹,

Plank²,

Berghold

et al. 2004

Diabetologia

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“…To estimate standard errors of change scores using the formula described by Elbourne et al, 6 we assumed conservatively that the correlation between before and after tests to be 0.5, which is common for crossover trials. 3 All statistical testing used the generic inverse variance method 8 and were performed by Review Manager 4.2.7 (The Cochrane Collaboration, Copenhagen, Denmark). 17 Results were considered statistically significant if PϽ.05.…”

Section: Data Extractionmentioning

confidence: 99%

The Effect of Low-Dye Taping on Kinematic, Kinetic, and Electromyographic Variables: A Systematic Review

Radford¹,

Burns²,

Buchbinder³

et al. 2006

J Orthop Sports Phys Ther

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Study Design: A systematic review. Objective: To determine the strength of evidence of the effect of low-Dye taping on lower limb kinematic, kinetic, and electromyographic variables. Background: Low-Dye taping is a foot-taping technique that aims to limit foot pronation and is commonly used to treat a number of foot disorders. Methods and Measures: Systematic review of randomized or quasi-randomized trials examining the effect of low-Dye taping compared with no taping on kinematic, kinetic, and electromyographic variables. Trials were identified by searching CINAHL, EMBASE, MEDLINE, SPORTDiscus, and CENTRAL, and by recursive checking of bibliographies. Data were extracted from published trials and from mail contact with authors for further information as necessary. Meta-analyses were planned for all outcomes using the generic inverse variance method. Sensitivity analyses were planned by pooling data from nonrandomized trials. Statistical heterogeneity was assessed using the quantity I 2 . Results: Six trials met inclusion criteria and, of these, 5 trials reported sufficient data on kinematic and kinetic variables to be included in the analysis. Results from the 5 randomized trials were considered robust when pooled with data from 7 nonrandomized trials in a sensitivity analysis. When compared to no taping, low-Dye taping increased navicular height immediately after application (weighted mean difference [WMD], 5.90 mm; 95% confidence interval [CI], 0.41 to 11.39; P = .04) and had no effect on navicular height post exercise (WMD, 4.70 mm; 95% CI, -0.61 to 10.01; P = .08), maximum rearfoot eversion while walking (WMD, -0.59°; 95% CI, -2.53 to 1.35; P = .55), and total rearfoot range of motion while walking (WMD, 2.3°; 95% CI, -0.64 to 5.24; P = .13). Conclusions: Low-Dye taping provides a small change in navicular height post application, although it is unclear whether this change is clinically important. There was high heterogeneity between some trials examining other variables, indicating that more research is needed to confirm the results of previous trials. J Orthop Sports Phys Ther 2006;36(4):232-241.

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“…If the numbers for n AB and n BA were not reported, we assumed that the sample was split half for the two sequences. For Hedges' g an SE was calculated as follows: 146,147 SE ¼ ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ffi n AB þ n BA 4n AB Ã n BA þ Hedges'g 2 2ðn AB þ n BA À 3:94Þ s…”

mentioning

confidence: 99%

Mood is indirectly related to serotonin, norepinephrine and dopamine levels in humans: a meta-analysis of monoamine depletion studies

2007

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Dysfunction in the monoamine systems of serotonin (5-HT), norepinephrine (NE) and dopamine (DA) may causally be related to major depressive disorder (MDD). Monoamine depletion studies investigate the direct effects of monoamines on mood. Acute tryptophan depletion (ATD) or para-chlorophenylalanine (PCPA) deplete 5-HT, acute phenylalanine/ tyrosine depletion (APTD) or alpha-methyl-para-tyrosine (AMPT) deplete NE/DA. Available depletion studies found conflicting results in heterogeneous populations: healthy controls, patients with previous MDD in remission and patients suffering from MDD. The decrease in mood after 5-HT and NE/DA depletion in humans is reviewed and quantified. Systematic search of MEDLINE and EMBASE (1966-October 2006) and cross-references was carried out. Randomized studies applying ATD, PCPA, APTD or AMPT vs control depletion were included. Pooling of results by meta-analyses was stratified for studied population and design of the study (within or between subjects). Seventy-three ATD, 2 PCPA, 10 APTD and 8 AMPT studies were identified of which 45 ATD and 8 APTD studies could be meta-analyzed. 5-HT or NE/DA depletion did not decrease mood in healthy controls. 5-HT or NE/DA depletion slightly lowered mood in healthy controls with a family history of MDD. In drug-free patients with MDD in remission, a moderate mood decrease was found for ATD, without an effect of APTD. ATD induced relapse in patients with MDD in remission who used serotonergic antidepressants. In conclusion, monoamine depletion studies demonstrate decreased mood in subjects with a family history of MDD and in drug-free patients with MDD in remission, but do not decrease mood in healthy humans. Although depletion studies usefully investigate the etiological link of 5-HT and NE with MDD, they fail to demonstrate a causal relation. They presumably clarify a vulnerability trait to become depressed. Directions for further investigation of this vulnerability trait are proposed.

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Meta‐analysis combining parallel and cross‐over clinical trials. I: Continuous outcomes

Cited by 192 publications

References 22 publications

Meta-analysis of short-acting insulin analogues in adult patients with type 1 diabetes: continuous subcutaneous insulin infusion versus injection therapy

Meta-analysis of short-acting insulin analogues in adult patients with type 1 diabetes: continuous subcutaneous insulin infusion versus injection therapy

The Effect of Low-Dye Taping on Kinematic, Kinetic, and Electromyographic Variables: A Systematic Review

Mood is indirectly related to serotonin, norepinephrine and dopamine levels in humans: a meta-analysis of monoamine depletion studies

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