Showing 6 results for Methodology
R Heshmat, A.a Keshtkar, R Sheykh-Ol-Eslam, M Baghery, A Nadim,
Volume 1, Issue 1 (12-2005)
Abstract
Background and Objectives:To compare three different methods of signal detection applied to the Adverse Drug Reactions registered in the Iranian Pharmacovigilance database from 1998 to 2005.
Materials and Methods:All Adverse Drug Reactions (ADRs) reported to Iranian Pharmacovigilance Center from March 1998 through January 2005, were included in the analysis. The data were analyzed based on three different signal detection methods including Reporting Odds Ratios (PRRs), Bayesian Propagation Neural Network (BCPNN) and Reporting Odds Ratios (RORs). Signals detected by each method were categorized based on the number of reports per drug-adverse event combination, severity of the event and labeled or unlabeled ADRs. The methods applied to signal detection were then compared in recognizing different types of adverse events.
Results: A total of 6353 cases of ADR reports, describing 11130 reactions, were reported to Iranian Pharmacovigilance Center (IPC) during the study period. The dataset involved 4975 drug-event combinations, which were assessed for detecting signals.
The counts of drug-event combinations was 1, 2 and 3 or more for 3470, 727 and 779 combinations, respectively. There were 500 drug items responsible for 468 reaction terms in the database. According to PRR and 95% Confidence Interval, there were 2838, 872 and 488 drug-event combinations known as a signal for the pairs with the reporting frequency of ³1, ³2 and ³3 reports, respectively. The signals detected with the criteria of PRR³2, c2³4 were 2930, 872 and 480 for the pairs with the same reporting frequencies.
Estimates of RORs and the 95% Confidence Interval showed that 2722, 862 and 481 drug-event combinations were detected to be signal for the pairs with the reporting frequency of ³1, ³2 and ³3 reports, respectively, while measuring IC and IC-2SD detected 1120, 378 and 235 cases for the same reporting frequencies. There were 234 signals detected by all three methods.
Conclusion: Despite the similarities between data mining methodologies for signal detection, there are differences in the numbers of signals detected by each method. The study findings suggest that quantitative signal detection methods should be added to the routine Pharmacovigilance activities in Iran and the trends for quantitative measures over time should be monitored.
Aa Haghdoost,
Volume 5, Issue 1 (6-2009)
Abstract
Sample size estimation is one of the crucial issues in the research methodology in medical sciences. It is an important issue for not only researchers but also readers of medical papers their frequent questions show how much they need to simple but accurate information.
This paper presents the basic concepts of sample size calculation, and simplifies complicated issues using concrete examples to clarify the concept of sample size estimation for none-professional readers in statistics. The paper starts with explaining the basic concepts of sample size calculation such as effect size, confidence interval and confidence coefficient, statistical errors, and assumptions in sample size calculation. Then, it presents the common formulae in the sample size calculation to estimate a mean, a proportion, to compare two means and to compare two proportions.
H Akbarein, A Bahonar, Oa Nekouei Jahromi, H Sharifi,
Volume 7, Issue 1 (6-2011)
Abstract
Background and Objectives: Designing and application of experimental studies in veterinary medicine have
been given paid more attention in recent years. This review aimed to evaluate the methodological quality of all
published articles in Journal of the Faculty of Veterinary Medicine, University of Tehran between 2000 and 2009.
Methods: Evaluation studies with experimental designs were identified by reviewing titles and abstracts. Two
reviewers coded reporting quality of articles.
Results: Of the 738 total published articles, 289 (39.16%) articles had experimental designs. Sample size was
reported in 93.4% of studies, only 36% of studies explained their study design clearly and randomization was
reported only in 33.6%. The ethical approval was mentioned in only two percent. Seventy six percent studies had
comparison group.
Conclusion: The quality of reporting of experimental studies in the Journal of the Faculty of Veterinary Medicine
was not generally acceptable. Therefore it is felt that authors should consider more necessary criteria for
standard publication in veterinary journals.
M Shokouhi, E Mohebbi, A Rastegari, S Hajimaghsoudi, Aa Haghdoost, Mr Baneshi,
Volume 10, Issue 1 (6-2014)
Abstract
Knowing the population size of rare diseases or special subpopulations like injection drug users (IDUs) is one of the most important challenges in public health and health surveillance systems but it is difficult to estimate these groups. During the last few years, new methods have been suggested to estimate hidden or hard-to-reach populations, one of which is the network scale-up method (NSUM). The NSUM itself includes measuring the personal network size and estimating the prevalence of hidden and hard-to-count populations. In this paper, we basically discussed the indirect methods of calculating the population size, and the history of NSUM and its concepts, and then addressed the estimation of hidden populations with NSUM and the applicable notes for such populations.
Hr Gilasi, H Soori, Sh Yazdani, P Taheri Tenjani ,
Volume 11, Issue 2 (9-2015)
Abstract
Background and Objectives: Managers need the results of scientific researches for executive planning. Considering some methodological errors in reported studies in Iran and the lack of specific and summarized references, this article aims to provide practical considerations in elderly studies.
Methods: In this narrative review, we conducted a comprehensive search in all accessible electronic data bases using “epidemiology” or “methodology” and “elderly” or their synonyms as keywords. Related papers and books were selected. After review, considerable notes were extracted and presented.
Results: Considering attrition, death, and non-response rates in sample size calculation, proportional sampling from all strata, and considering differences in clinical manifestations and diagnosis are important. Matching for main confounders, considering recall bias, creating a quiet and comfortable environment to conduct the interview, allocating a certain percentage of participants to high risks, registering age and other quantitative variables in detailed and non-categorized formats, home visit for interview after receiving informed consent from the elderly or their guardians, interview at the closest location to the elderly’s residence, avoiding long interviews, considering bold and legible words in designing the questionnaire, data re-checking with proxy and documents, applying age and sex adjustment for rates, evaluating the functional status, appropriate interpretation related to odds ratio and considering the cost of the studies are the most essential considerations in aging studies.
Conclusion: Using epidemiological methods with respect to the characteristics of the elderly enhances the quality of the collected data. Well designed studies provide policy makers with reliable evidence for planning.
F Fakhri, S Eybpoosh, M Solaymani Dodaran ,
Volume 15, Issue 1 (5-2019)
Abstract
Background and Objectives: A considerable number of clinical trials are conducted in Iran each year. Not much is known about the characteristics of them, this study aimed to investigate key characteristics of Iranian clinical trials.
Methods: All clinical trial protocols registered in IRCT until November 2013 were selected. Text mining techniques were used to extract information from data that was mostly in the textual format. Stata software (v. 11) was used for both extraction and analysis.
Results: Totally 5049 trials where analyzed. Trials were in 40 different areas of medicine and their annual number was increasing. The sample size of registered trials was less than 70 in most trials and showed no significant improvement during the 5-year period (Median sample size= 64, inter quartile range (IQR) = 40-100). Phase III trials comprised 8.4% of the trials with a median sample size of 75 (IQR= 50-120). Of all phase III trials, 69% had a target sample size of less than 100. Most trials used randomization techniques (87.2%) but failed to use placebo (65.3%) and double/triple-blinding techniques (55.8%). The leading sponsors for 99.9% of trials were national bodies and 92.2% of the trials received public funds. Only 1% of the trials were exclusively sponsored by pharmaceutical companies.
Conclusion: The majority of clinical trials conducted in Iran are investigator-initiated and are funded by the public sector. The small sample size and failures in bias control observed in the majority of trials highlights the need for revising current policies of conducting trials in Iran.
