Iranian Journal of

Background & Objectives: The standard methods for the comparison of two drugs in a randomized controlled clinical trial in the presence of non-compliance are intention-to-treat or per-protocol approaches. Both approaches have problems with estimation of drug effects, and researchers are not still certain to adopt which one. In this study, the bias of intention-to-treat and per-protocol approaches was calculated using Monte-Carlo simulation. We tried to choose the best approach (based on the AIC index) for comparing Risperidone plus Celecoxib and Risperidone plus Placebo.

Methods: This secondary study was conducted to compare the effect of Risperidone plus Celecoxib and Risperidone plus Placebo among 60 schizophrenic patients. To choose between the intention-to-treat and per-protocol approaches, Monte-Carlo simulation with Ackaike (AIC) and Baysian (BIC) indices was used.

Results: The results of Monte-Carlo simulation showed that when the sample size was small (n=30 or n=60) under fixed conditions of non-compliance equal to 5% and 10%, intention-to-treat had a better goodness of fit than per-protocol based on AIC and BIC. However, increasing the sample size in active and placebo groups (e.g., n=100) showed that per-protocol had a better goodness of fit than intention-to-treat.

Conclusion: When the sample size is large, the per-protocol approach may have a better goodness of fit than intention-to-treat to address the effects of non-compliance in randomized clinical trials.

  Background and Objectives : Various studies have reported different survival rates of patients with gastric cancer in Iran, and there is no overall estimate of the survival rate. The aim of this study was to conduct a meta-analysis of one, three, and five-year survival rate of patients with gastric cancer in Iran.

  Methods: In this study, all of the national databases including Iran Medex, Magiran, SID, and Medlib and the English databases including Google Scholar and PubMed were searched by using the keywords “stomach cancer”, “survival rate” and other Persian and English synonymous keywords, in the period 1392-1339 . Then, all articles with inclusion criteria and acceptable quality were investigated. Der Simonian and Laird random effects models were used to combine the results of all studies. Other analyses including subgroup analysis, sensitivity analysis, and assessment of publication bias were performed by using the funnel plot, and Beg’s and Egger’s tests. Finally, the data was analyzed using STATA software.

  Results: Of the 235 articles found in the initial search, nine studies were eligible for this study. According to these studies, one, three and five-years survival rate of patients with gastric cancer was 0.57 (95% CI: 0.45-0.70), 0.29 (95% CI: 0.22-0.37), 0.17 (95% CI: 0.13-0.21), respectively.

  Conclusion : Researches conducted in different parts of Iran are limited and there are no exact statistics on the survival rate in other parts of Iran. Therefore, further studies in the whole country are required to obtain more precise estimates of the survival and factors affecting it.