Assessing the quality of randomized controlled trials from two leading cancer journals using the CONSORT statement

No study has been conducted on the scientific quality of randomized controlled trials [RCTs] in the cancer field. Our objective was to determine whether adherence to the Consolidated Standards for Reporting Trials [CONSORT] statement is associated with scientific properties of RCT reports from two leading cancer journals. We conducted an observational study of RCTs published between 2002 and 2004 in two leading cancer journals that did not endorse the CONSORT statement during that period. We determined the adherence rates with confidence intervals of 33 RCTs according to the 19 methodological items of the CONSORT statement. Each RCT was blindly assessed by three independent evaluators; then the evaluators examined all judgments sequentially and obtained a consensus regarding each methodological item of the CONSORT statement. The average adherence of these 33 RCTs to the 19 methodological items of the CONSORT statement was 79.3% [95% CI, 75.3-83.4%]. Most descriptors from the checklist were determined to be methodologically adequate except sequence generation [56.1%; 95% CI, 40.9-71.3%], allocation concealment [27.3%; 95% CI, 13.2-41.4%], implementation [7.6%; 95% CI, 0.0-15.4%], blinding [30.3%; 95% CI, 14.4-46.3%] and sample size [74.2%; 95% CI, 59.5-89.0%]. Of all CONSORT checklist items, randomization implementation was the most often omitted. Some key methodological items of the CONSORT statement seem poorly addressed in RCTs from these leading cancer journals. Thus researchers should be urged to conform to the CONSORT statement when reporting on RCTs, and the poorly addressed items of the CONSORT statement should be reevaluated for RCTs already reported

Evaluating "superiority", "equivalence" and "non-inferiority" in clinical trials

Clinical studies are usually performed with the aim of justifying that a new treatment approach is "superior" to the common standard approach [active control] with respect to benefits. In a general sense, this justification is carried out on the basis of the "null hypothesis significance test" with the P value based on this test used for justification. Today, new drugs differ so little from existing ones that factors such as cost and side effects affect the choice of therapy, when the bioavailability of treatment methods are found equivalent. Therefore, the aim of comparative clinical trials has extended beyond showing that a treatment is "superior" and now attempts to show that new treatments are "equal" and "non-inferior" to existing treatments. New approaches have become necessary since the classical null hypothesis approach is insufficient to justify the use of new agents, especially in cases of "equivalence" and "non-inferiority". This new approach to justification makes use of the "clinical equivalence interval", which determines the limits of the differences between specific endpoints that can be regarded as clinically "equal" to the value that was pre-specified based on studies of established therapies. It also makes use of the quantitative-based "confidence intervals" as the criteria for statistical justification. Many analyses can be done confidently when these tools are applied and the data are interpreted correctly

prevalence and the age at the onest of menopause in Turkish women in rural aera

To find out the prevalence of natural menopause among Turkish women according to age and certain demographic variables in a specific rural area. This cross sectional study was carried out in Silivri district of Istanbul, Turkey between January and May 2000. Included in the study were 845 women between the ages of 30-60 years, not undergoing any hormonal replacement, living in the villages of Silivri district, Istanbul, Turkey. The participants were asked for their ages, level of education, number of pregnancies, age at menarche, presence of menstruation, age at the onset of menopause, physical activity outside home and the use of oral contraceptives. Females declaring at least one year of amenorrhea were accepted as being in menopause. The median age for menopause was 47 years. Of the total 845 participants, 326 women were found to be in natural menopause. The prevalence of menopause was estimated as 8.6% for females younger than 40 years, 31.8% for females between the ages 40-45 years and 80.9% among females older than 45 years. Any of the variables questioned in our study have an effect on premature onset of menopause, but we found that never been pregnant [p=0.037, odd ratio [OR]=2.221, 95% confidence interval [CI]=1.048, 4.707] reduces the reproductive period, and the age at menarche younger than 13 prevents early menopause [p=0.000, OR=0.336, 95% CI=0.195, 0.579]. Furthermore, both lead to early onset of menopause. Hazard ratios of the variables that have an effect on the onset of early menopause are calculated as 2:10 [95% CI=1.01, 4.39] for those who were never been pregnant and 1:10 for those with the menarche ages over 13 years [95% CI=0.68, 1.78]. There was a noticeably high percentage of females [8.6%] younger than 40 years who were entering menopause. On the other hand, an early onset of natural menopause among Turkish women living in this rural area was found to be associated with never been pregnant and their age of menarche