Iranian Journal of

---

Background & Objectives: Despite decreasing the trend of coronary artery diseases in developed countries and outstanding improvements in clinical management of these patients, case fatality rate after an acute myocardial infarction (AMI) remains high in both genders. Identifying predicting factors of short-term survival in patients with AMI may play an important role in reducing mortality in these patients.
Methods: In this cohort study, all patients with acute myocardial infarction (AMI) admitted to all hospitals in Isfahan, Iran, during 2000-2008 which registered in Isfahan cardiovascular research Institute were analyzed. We used Cox regression models, uni- and multi-variable analysis. 
Results: Within the study period, 8800 AMI patients (73.6% male) were admitted with mean age of 61.85±12.5, and overall 28-day survival of 90.5%. Relative risk (RR) of death for 50-70 years old patients was 2.5 (CI:2-3.1), for over 70 years old RR=5 (CI:4-6.3), for women RR=1.7 (CI:1.5-1.9), for patients who had not received streptokinase RR=0.9 (CI:0.8-1.1), for inferior MI RR=4.2 (CI:2.2-7.8) and for anterior MI, RR was equal to 7.2 (CI:4-13.3).
Conclusion: Recognizing the predicting factors of short-term survival of AMI patients may help health professionals to provide better healthcare services for more at risk patients, i.e. elderly, women and patients with an anterior MI.

---

  Background & Objectives : The length of stay (LOS) is a useful indicator that can be used according to the objective to improve hospital care performance. The purpose of our study was to find factors affecting infants LOS in NICU at Children's Medical Center, Imam Khomeini Hospital, Tehran University of Medical Sciences, using the Cox multiple hazards regression model.

  Methods : This historical cohort study reviewed 369 medical records of all NICU admitted newborns at Children's Medical Center in 2009. The required data were collected through a data collection form. The Cox multiple hazards regression model was used to determine the factors affecting LOS in infants who were discharged on the physician‘s order.

 Results: The median of stay in NICU was 9 days. Of 369 infants, 272 were discharged with improvement. The results of multiple Cox proportional hazards regression model showed the following factors were associated with LOS in the NICU: prematurity, referral from other hospitals, gastrointestinal diseases and infections, central venous catheterization, mechanical ventilation, and antibiotic therapy (P < 0.05).

  Conclusion : Cox proportional hazards regression model should be used when the dependent variable is time and we have censored data. Improving prenatal health care, constructing NICU in hospitals with high risk labor, reduction of preterm birth risk factors, and improving primary health-care services can help us to reduce LOS in NICU.

---

  Background & Objectives : Gastric cancer has a low survival and remains a serious threat to the health of human life, especially in developing countries such as Iran. The present study was performed to estimate the main effective factors in the survival rate of patients with gastric cancer in the Province of Kohgilouyeh & Boyerahmad.

  Methods: All cases of gastric cancer in Kohgiloyeh and Boyerahmad recorded in Provinces of Fars and Kohgiloyeh and Boyerahmad cancer registry were enrolled in this study. The impact of the independent variables on the survival was estimated by single and multivariate Cox regression controlled for the probable confounding variables. Survival analysis was performed using Kaplan Meier curves, the log-rank test, and Wilcoxon test to compare the results. Analysis of the data was performed by SPSS 19, and P-values less than 0.05 were considered significant.

 Results: Among the 348 studied patients, 75.6% were male and the rest (24.4%) were female. In general, in this study, 1, 2, 3, 4, and 5-year survival rate of the patients was 37, 27, 20, 19, and 18%, respectively. By combining these end variables in regression models, three risk groups were identified. In the high risk group, the cumulative survival rate was 0% at the end of the fifth year.

 Conclusion: Execution of the down-staging program through public education, considering the low survival rate in this province seems essential especially for high-risk groups such as farmers, ranchers and regional nomadic populations.