A comparison of breast cancer survival among young, middle-aged, and elderly patients in southern Iran using Cox and empirical Bayesian additive hazard models / 한국역학회지

OBJECTIVES: A survival analysis of breast cancer patients in southern Iran according to age has yet to be conducted. This study aimed to quantify the factors contributing to a poor prognosis, using Cox and empirical Bayesian additive hazard (EBAH) models, among young (20-39 years), middle-aged (40-64 years), and elderly (≥ 65 years) women. METHODS: Data from 1,574 breast cancer patients diagnosed from 2002 to 2012 in the cancer registry of Fars Province (southern Iran) were stratified into 3 age groups. The Kaplan-Meier method was used to estimate the overall survival rates. Cox and EBAH models were applied to each age category, and the Akaike information criterion was used to assess the goodness-of-fit of the 2 hazard models. RESULTS: As of December 2012, 212 women (13.5%) in our study population had died, of whom 43 were young (15.3%), 134 middle-aged (11.8%), and 35 elderly (22.3%). The 5-year survival probability by age category was 0.83 (standard error [SE], 0.03), 0.88 (SE, 0.01), and 0.75 (SE, 0.04), respectively. CONCLUSIONS: The Nottingham Prognostic Index was the most effective prognostic factor. The model based on Bayesian methodology performed better with various sample sizes than the Cox model, which is the most widely used method of survival analysis.

A comparison of breast cancer survival among young, middle-aged, and elderly patients in southern Iran using Cox and empirical Bayesian additive hazard models / 한국역학회지

OBJECTIVES: A survival analysis of breast cancer patients in southern Iran according to age has yet to be conducted. This study aimed to quantify the factors contributing to a poor prognosis, using Cox and empirical Bayesian additive hazard (EBAH) models, among young (20-39 years), middle-aged (40-64 years), and elderly (≥ 65 years) women.METHODS: Data from 1,574 breast cancer patients diagnosed from 2002 to 2012 in the cancer registry of Fars Province (southern Iran) were stratified into 3 age groups. The Kaplan-Meier method was used to estimate the overall survival rates. Cox and EBAH models were applied to each age category, and the Akaike information criterion was used to assess the goodness-of-fit of the 2 hazard models.RESULTS: As of December 2012, 212 women (13.5%) in our study population had died, of whom 43 were young (15.3%), 134 middle-aged (11.8%), and 35 elderly (22.3%). The 5-year survival probability by age category was 0.83 (standard error [SE], 0.03), 0.88 (SE, 0.01), and 0.75 (SE, 0.04), respectively.CONCLUSIONS: The Nottingham Prognostic Index was the most effective prognostic factor. The model based on Bayesian methodology performed better with various sample sizes than the Cox model, which is the most widely used method of survival analysis.

Longitudinal standards for growth velocity of infants from birth to 4 years born in West Azerbaijan Province of northwest Iran / 한국역학회지

OBJECTIVES: Growth velocity is an important factor to monitor for appropriate child growth. This study presents the growth velocity of infants based on length, weight, and head circumference. METHODS: The subjects of this study were 308 neonates (160 boys and 148 girls) born in West Azerbaijan Province of northwestern Iran who were followed from birth for 4 years. The weights and lengths of the subjects were recorded at birth, 1, 2, 4, 6, and 9 months, and 1, 1.5, 2, 3, and 4 years of age, while the head circumferences were measured just up to 1.5 years of age. In this study, the Lambda-Mu-Sigma (LMS) method using LMS Chartmaker Pro (Institute of Child Health, London, UK) was utilized to obtain growth velocity percentiles. RESULTS: After obtaining growth velocity charts for weight, length, and head circumference (5th, 50th, and 95th percentiles), the researchers could deduce that there was a sharp decrease in the velocity growth charts from birth to 2 years of age but these charts remained relatively stable up to 4 years for both sexes. Growth velocities for the length and weight of boys in the present sample are slightly but not significantly greater than those in girls through the first months of infancy and there was no significant difference between girls and boys up to 4 years. CONCLUSIONS: This paper provided the first local growth velocity standards of length, weight, and head circumference for infants by analyzing longitudinal measurements produced for West Azerbaijan Province, which should be updated periodically. It seems that there has been a significant difference between the growth velocity of infants in northwestern Iran and southern Iran within the past few years.

Prognostic factors of first birth interval using the parametric survival models

In recent years, the study of birth intervals has been a main determinant of the levels of fertility in the populations, as it is associated with rates of fertility and population growth. The purpose of this study was to firstly apply survival analysis for modeling of first birth interval and secondly to explore its determinants. In a cross sectional study, the fertility history of 858 women was collected in rural areas of Shiraz [southern Iran] in 2008. We used the survival analysis such as cox regression and alternative parametric models to evaluate the prognostic factors of first birth interval. Among the explanatory variables of interest, age at marriage, level of women's education, and menstrual status had highly significant effects on the duration of birth interval after marriage [p<0.01]. It is concluded that the suitable parametric models would be a useful tool for fitting to first birth interval, the fact that has been less paid attention to in researches

Blood pressure standards for Shiraz [southern Iran] school children in relation to height

This study aims at providing local reference values for blood pressure by height and determining distribution pattern of systolic and diastolic blood pressure in 6.5-11.5 elementary school children for the first time in Shiraz [Southern Iran]. Height, systolic blood pressure [SBP] and diastolic blood pressure [DBP] were measured with standard methods in 2270 healthy school children [1174 boys, 1096 girls] who were selected by multi-stage random sampling in 2003-2004 academic years. We produced blood pressure percentiles by height percentiles using Healy-Rasbash-Yang method. The blood pressure [both systolic and diastolic] tends to increase with age, but after adjusting the measurements for height, no significant correlation was found between either systolic blood pressure or diastolic blood pressure and age [r=-0.03 and P=0.15 for systolic blood pressure, r=-0.005 and P=0.8 for diastolic blood pressure]. Then systolic and diastolic blood pressure percentile values by age and height percentiles, and blood pressure smoothed centiles by height in 6.5-11.5 years school children were derived. Due to genetic, cultural and environmental difference among populations, it is suggested to use local blood pressure standards in Iran. We produced blood pressure percentiles by height instead of age because it seems that it would lead to better evaluation for real hypertensive diagnosis

New trends in weight-for-height charts of Shirazi school children in relation to the CDC reference data

The paper presents a new trend of weight-for-height index of 2397 school children [1268 boys and 1129 girls] aged 6.5-11.5 years by sex in a representative sample from primary schools of Shiraz [Southern Iran[at an interval of 15 years [1988-2003] and its relation to the center for Disease Control and Prevention [CDC] data [2000]. The data relate to a multi-stage random sample of healthy school children in Shiraz, southern Iran, collected in 2002-2003 academic year. The mean +/- SD age of these children was 9.1 +/- 1.4 years. The weight and height were estimated as 28.2 +/- 6.9 kg and 131 +/- 9.6 cm, respectively. Cross-sectional weight-for-height curves were constructed for both sexes. Parametric Lambda-Median-Standard Deviation [LMS] method was applied to estimate weight-for-height centiles. Weight-for-height centiles for boys and girls were nearly close to each other, except for the children of older age in which boys' centiles lay below those of girls. Centiles of the present study lay above previous ones. In both sexes CDC weights were greater than those of Iranians for a given height. This discrepancy was more pronounced in extreme high centiles. The necessity for updating local weight-for-height reference data for clinical work in Iran is emphasized. The positive trend in weight-for-height had been influenced by socio-economic development and improvement of health indicators in Iran during the post war reconstruction period