Home About us Contact
|
Home About us Contact | ||
|
|
||
Way ANOVA (way + anova)
Selected AbstractsCalculation of sample size for stroke trials assessing functional outcome: comparison of binary and ordinal approachesINTERNATIONAL JOURNAL OF STROKE, Issue 2 2008The Optimising Analysis of Stroke Trials (OAST) collaboration Background Many acute stroke trials have given neutral results. Sub-optimal statistical analyses may be failing to detect efficacy. Methods which take account of the ordinal nature of functional outcome data are more efficient. We compare sample size calculations for dichotomous and ordinal outcomes for use in stroke trials. Methods Data from stroke trials studying the effects of interventions known to positively or negatively alter functional outcome , Rankin Scale and Barthel Index , were assessed. Sample size was calculated using comparisons of proportions, means, medians (according to Payne), and ordinal data (according to Whitehead). The sample sizes gained from each method were compared using Friedman 2 way ANOVA. Results Fifty-five comparisons (54 173 patients) of active vs. control treatment were assessed. Estimated sample sizes differed significantly depending on the method of calculation (P<0·0001). The ordering of the methods showed that the ordinal method of Whitehead and comparison of means produced significantly lower sample sizes than the other methods. The ordinal data method on average reduced sample size by 28% (inter-quartile range 14,53%) compared with the comparison of proportions; however, a 22% increase in sample size was seen with the ordinal method for trials assessing thrombolysis. The comparison of medians method of Payne gave the largest sample sizes. Conclusions Choosing an ordinal rather than binary method of analysis allows most trials to be, on average, smaller by approximately 28% for a given statistical power. Smaller trial sample sizes may help by reducing time to completion, complexity, and financial expense. However, ordinal methods may not be optimal for interventions which both improve functional outcome and cause hazard in a subset of patients, e.g. thrombolysis. [source] Travel Insurance Claims Made by Travelers from AustraliaJOURNAL OF TRAVEL MEDICINE, Issue 2 2002Peter A. Leggat Background: Little is known about travel insurance claims made by travelers returning from abroad. This study was designed to investigate travel insurance claims made by travelers from Australia, particularly examining demographic factors, type of travel insurance coverage, nature and duration of travel, when treatment was sought during travel or when the problem arose, use of emergency assistance, nature of claim, and claim outcome, including cost. Methods: A random sample of approximately one in five claims reported during the period 1996 to 1998 to a major Australian travel insurance company were examined. Results: A total of 855 claims were examined, of which 42.6% (356/836) were made by male travelers and 57.1% (477/836) were made by female travelers. The majority of claimants were in the 55 years and over age groups (445/836, 53.2%). Medical and dental conditions accounted for 66.6% of claims (569/854), with the remainder associated with loss, theft, and damage (285/854, 33.4%). The most common medical conditions were respiratory (110/539, 20.4%), musculoskeletal (90/539, 16.7%), gastrointestinal (75/539, 13.9%), ear, nose, and throat (67/539, 12.4%), and dental conditions (39/539, 7.2%). Only one case of venous thrombosis was reported, secondary to a lower limb infection. Use of the travel insurance company's emergency telephone service was reported in 17.1% of claims (146/853). Almost two-thirds (559/853, 65.5%) of claims were fully accepted. Those who claimed medical treatment, assault, and theft were significantly more likely to have their claims accepted compared to those claiming dental conditions, cancellation, curtailment, loss and damage (,2= 127.78, df = 40, p < .00001). The majority of medical and dental conditions did not require further medical investigations (427/569, 75.0%). The mean cost of claim refunds was Australian dollars (AUD)991.31 (standard deviation [SD] ± AUD5400.76) for males and AUD508.90 (SD ± AUD1446.10) for females. Claims for assault, cancellation, and curtailment were significantly more expensive than other types of claims (Kruskal-Wallis one way analysis of variance [ANOVA]; ,2= 106.87, df = 8, p < .00001). Claims for treatment of gastrointestinal, cerebrovascular, cardiovascular, musculoskeletal conditions, and pyrexias of unknown origin were significantly more expensive than other medical and dental claims (Kruskal-Wallis one way ANOVA; ,2= 61.68, df = 15, p < .00001). Conclusions: This explorative study highlights the importance of travelers taking out appropriate travel insurance. Claims for medical and dental conditions represent the majority of travel insurance claims made by Australian travelers returning from abroad, although travel insurance also covers against such contingencies as loss, theft, and cancellation. The most common medical conditions claimed were respiratory, musculoskeletal, and gastrointestinal disorders. Travelers should be advised to take out appropriate travel insurance before departure overseas and to take care with preexisting medical and dental conditions, which may not be able to be claimed against travel insurance. [source] Synergistic Interactions Between a KCNQ Channel Opener and an Opioid: Flupirtine and Morphine in Rat Pain Models Including Neuropathic PainPAIN MEDICINE, Issue 7 2007C Goodchild Purpose of the study:, Flupirtine is an established clinical analgesic for mild to moderate musculoskeletal pain states. It has recently been shown to be a KCNQ 2,3 potassium channel opener. These experiments were performed to see if this property could be useful in treating more severe pain states characterised by central sensitisation with the drug either given alone or in combination with morphine. Methods:, Experiments were performed in rats in an observer blinded fashion with vehicle controls. Non sedating doses of flupirtine, morphine and combinations containing both drugs were defined using the rotarod technique. Dose response relationships were determined for non sedating doses of both drugs given alone and together in combination in causing antinociception in three nociception paradigms: electrical pain; carrageenan paw inflammation; streptozotocin-induced diabetic neuropathy. Results:, Flupirtine and morphine when given alone caused slight to moderate antinociception in all three paradigms. Flupirtine also caused significant increases in morphine antinociception in all three models. In carrageenan paw inflammation complete reversal of carrageenan-induced hyperalgesia was caused by 10 mg/kg flupirtine in combination with 0.4 mg/kg morphine. These doses of the two drugs were ineffective when given alone but the combination caused complete antinociception in this model of inflammatory pain. In the diabetic neuropathy model (see figure) morphine 3.2 mg/kg given alone caused significant antinociception but the size of that response was significantly less than that caused by a lower dose of morphine (1.6 mg/kg shown to be ineffective when it was given alone) given in combination with flupirtine 10 mg/kg (p < 0.001; one way ANOVA). Conclusions:, Flupirtine should be investigated as an adjunct analgesic with opioids for the management of patients with severe pain states involving central sensitization. [source] Effect of conditioning films and a novel anti-adherent agent on bacterial adherence to dentineINTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2001A. Maglad Aim,Adherence of bacteria to dentine is a prerequisite to infection of the root canal system, yet adherence of root canal bacteria to dentine is poorly understood. The aim of this study was to evaluate the effect of conditioning films and anti-adherent compounds on bacterial adherence to dentine. Methodology,Freshly extracted molar teeth were prepared and sectioned to give 225 discs of predetermined dimensions. The discs were allocated to two groups. Group 1 (n = 189) was divided into three subgroups (n = 63) and coated with one of three conditioning agents (artificial saliva, serum, or distilled water) prior to bacterial inoculation. Group 2 discs (n = 36) were treated with either a novel anti-adherent agent (PC1036, Biocompatibles) (n = 18) or distilled water (n = 18) prior to conditioning with artificial saliva. Monospecies bacterial biofilms were generated on the dentine discs by incubating them in brain heart infusion broth (37 gL,1) containing Streptococcus intermedius (Si), Enterococcus faecalis (Ef) or Lactobacillus fermentum (Lf) (originally isolated from infected root canals). The number of bacteria adhering to the discs in each of the groups was determined using standard serial dilution protocols. Additional discs were prepared under all conditions for scanning electron microscopy. Where appropriate, statistical analysis by one way anova, post hoc Bonferroni, and independent t -test were used. Results,Si adhered significantly better to dentine when conditioned with serum compared with artificial saliva (P = 0.005) or distilled water (P = 0.009). Conversely, Ef adhered significantly better to the control discs (distilled water) compared with serum conditioned discs (P = 0.016). The conditioning films had no effect on the adherence of Lf, which adhered to the dentine discs significantly less (P = 0.001) than either Si or Ef. The anti-adherent coating significantly reduced the number of Si adhering to the dentine compared with the control (P = 0.012). Conclusion,Given the importance of adherence in root canal infection it is conceivable that an anti-adherent compound, could be used to prevent bacterial recontamination of cavities or the root canal system. [source] The influence of age and dental status on elevator and depressor muscle activityJOURNAL OF ORAL REHABILITATION, Issue 2 2006I. Z. ALAJBEG summary, The objective of this study was to determine whether the muscle activity at various mandibular positions is affected by age and dental status. Thirty edentulous subjects (E), 20 young dentate individuals (G1) and 20 older dentate individuals (G2) participated in this study. Surface electromyographic (EMG) recordings were obtained from the anterior temporal (T), masseter (M) and depressor muscles (D). Muscle activity was recorded during maximal voluntary contraction (MVC), maximal opening (Omax) and in six different mandibular positions. One way anova and the Bonferroni tests were used to determine the differences between groups. Significant differences between the three tested groups were found at MVC and Omax for all examined muscles (P < 0·001). The differences in muscle activity in dentate subjects of different age were found in protrusion for depressor muscles (P < 0·05) and in lateral excursive positions for the working side temporal (P < 0·05) and non-working side masseter and depressor muscle (P < 0·05). There was a significant effect regarding the presence of natural teeth or complete dentures in protrusion and maximal protrusion for all muscles (P < 0·05) and in lateral excursive positions for non-working side temporal (P < 0·05) and working side masseter muscle (P < 0·05). Muscle activity at various mandibular positions depends greatly on the presence of the prosthetic appliance, as edentulous subjects had to use higher muscle activity levels (percentages of maximal EMG value) than age matched dentate subjects in order to perform same mandibular movement. Different elevator muscles were preferentially activated in the edentulous subjects when compared with dentate group in lateral excursive positions of the mandible. The pattern of relative muscle activity was not changed because of ageing. [source] | ||||||||||