Showing 3 results for Nested Case-Control Study
R Chaman, A Shamshiri, K Kamali, Ghr Khalili, K Holakouie Naieni,
Volume 2, Issue 1 (3-2006)
Abstract
Background & Objectives: This investigation was prompted by the growing importance of nested case-control studies and the increasing frequency with which they are done in epidemiologic research. After a brief explanation of nested case-control studies, we evaluate the trends in research methodology over the last decade, especially with regard to cohort, case-control, and nested case-control designs.
Methods: Data for this study were extracted from the PubMed database, using these keywords: Nested Case-Control, Risk-Set Sampling and Density Sampling. The search was confined to the 10-year period from 1996 to the end of 2005. As for other methodologies, we used keywords Cohort and Case-Control for a search over the same time period. The search itself was performed on April 25, 2006.
Results: We found 2011 articles reporting nested case-control studies. There were 95 such articles in 1996 the number had increased to 289 in 2005. Case-control and cohort designs accounted for 68456 and 60479 articles, respectively.
The number of case-control articles rose from 4378 in 1996 to 10270 in 2005, while that of cohort articles increased from 2981 to 9771 over the same period.
Conclusions: The number of cohort and nested case-control articles followed similar upward trends over the last decade and their rate of increase was greater than that of simple case-control articles.
R Chaman , M Yunesian , B Golestan , K Holakouie Naieni ,
Volume 3, Issue 3 (2-2008)
Abstract
Background and Objectives: A pregnancy can be considered high-risk if there are conditions that put the mother or the baby at higher-than-average risk of morbidity or mortality. Neonatal mortality rate is one of the most important indices of children's health status. The present study was conducted to evaluate the effects of high-risk states on neonatal mortality.
Methods: We performed a nested case-control study in the rural areas of Kohgiluyeh and Boyerahmad province. Within the study cohort, 97 cases and 97 controls were selected by a risk-set sampling method. Data were analyzed with univariate and multivariate conditional logistic regression models.
Results: Neonatal mortality was shown to increase significantly in high-risk pregnancies. There were no substantial differences between crude odds ratios and those adjusted for the presence of other risk factors (crude odds ratio decreased from 5.5 to an adjusted figure of 3.25 for pregnancies with one risk factor and from 5.21 to adjusted level of 4.80 for pregnancies with more than one risk factor).
Conclusions: High-risk pregnancies need great attention in family health and prenatal care programs, especially in remote rural areas. Within our rural health network there are potential cohorts for use in nested case-control studies, especially in the evaluation of neonatal mortality risk factors.
B Moatamedizadeh, H Ansari, A Payandeh, Sm Tabatabae, A Ramazanpouramirdehi,
Volume 16, Issue 1 (6-2020)
Abstract
Background and Objectives: In addition to effective treatment, tuberculosis recurrence is a very important challenge regarding the treatment of this infection. This study was conducted to evaluate the risk factors associated with tuberculosis recurrence.
Methods: In this nested case-control study, 202 tuberculosis patients with recurrence and 202 matched controls in terms of age, sex and place of residence were studied. The cases and controls were selected from a cohort of tuberculosis patients in Sistan and Baluchestan province between 2011 and 2018. The data were collected using interviews and patients’ records. The independent t-test, chi-square and multiple conditional logistic regression were used to analyze the data.
Results: The drug abuse history (OR=6.1), 3+ smear positive (OR=3.03), chest X-ray suggestive of tuberculosis (OR=4.9), drug resistance (OR=7.3), low socioeconomic status (OR=3.9), weight loss (OR=3.1), chest pain (OR=3.2), history of digestive disease (OR=22.1), smoking (OR=6.1), and imprisonment (OR=3.7) significantly increased the chance of recurrence among tuberculosis patients (p<0.05). On the other hand, the chance of recurrence was significantly lower in patients with coughs (OR=0.29) and a small family size (OR=0.28).
Conclusion: According to the results, tobacco use, drug use, low socio-economic status, life conditions, and disease conditions are the most important determinants of tuberculosis recurrence. In general, epidemiologic factors related to tuberculosis recurrence are not similar in different regions; therefore, educational programs for patients and their families and prevention methods should be considered based on related factors in different regions.
