A paradoxical change in economic inequality in presenting visual acuity between 2009 and 2014: a nonuseful decline

Background: Despite the widespread literate on health inequalities and their determinants, changes in health inequalities over time have not received enough attention. Aims: To measure and decompose the over-time changes in economic inequality in presenting visual acuity measured using Logarithm of the Minimum Angle of Resolution. Methods: We analyzed 4,706 participants who had complete data on presenting visual acuity and economic status in 2009 and 2014 in the Shahroud Eye Cohort Study. We measured changes in presenting visual acuity concentration indices and decomposed them the using a longitudinal approach. Results: Both the presenting visual acuity and economic status deteriorated between 2009 and 2014. The mean (standard deviation) for presenting visual acuity and economic status scores in 2009 versus 2014 were 0.090 (0.2) versus 0.103 (0.2) and 0.01 (1.0) versus 0.0005 ( 1.07), respectively. Presenting visual acuity concentration index (95% confidence interval) in the first versus second phases of the study were –0.245 (–0.212 to –0.278) versus –0.195 (–0.165 to –0.225), respectively. Longitudinal decomposition of this change in concentration indices during the 5-year period indicated that the most important contributor to reduction in economic inequality of presenting visual acuity was deterioration of presenting visual acuity among people with higher economic status due to their aging. Conclusion: Unexpectedly, reduction in economic inequality in presenting visual acuity was due to presenting visual acuity deterioration among the higher economic status group rather than its amelioration among the lower economic status group. Therefore, the needs of all socioeconomic groups should be considered separately to modify presenting visual acuity in each group and, consequently, reduce the economic inequality in presenting visual acuity.

Life and health satisfaction in the adult population of Iran / 한국역학회지

OBJECTIVES: Increasing interest has emerged in the use of subjective well-being as a development indicator and for the evaluation of public policies. The aim of this study was to assess life and health satisfaction and their determinants in the adult population of Iran. METHODS: We conducted a survey of a sample of 3,150 adults at least 18 years of age in Tehran, the capital of Iran. The subjects were selected using a stratified random sampling method, and they were interviewed face-to-face at their usual residence by trained interviewers. Life satisfaction was used as a measure of subjective well-being. We used ordinary least square regression models to assess the associations of life and health satisfaction with socio-demographic variables. RESULTS: On a 0-10 scale, the mean (standard deviation) scores for life and health satisfaction were 6.93 (2.54) and 7.18 (1.97), respectively. The average score for life satisfaction in females was 0.52 points higher than in males. A U-shaped relationship was found between age and life satisfaction, with respondents 35 to 44 years of age having the lowest average level of life satisfaction. Satisfaction with life and health among divorced respondents was significantly lower than among never-married and married participants. The scores for life satisfaction in respondents who rated their health status as poor were 3.83 points lower than in those who rated their health status as excellent. CONCLUSIONS: The majority of the population of Tehran was satisfied with their life and health. Self-rated health status had the greatest impact on life satisfaction.

Assessing Markov and time homogeneity assumptions in multi-state models: application in patients with gastric cancer undergoing surgery in the Iran cancer institute.

BACKGROUND: Multi-state models are appropriate for cancer studies such as gastrectomy which have high mortality statistics. These models can be used to better describe the natural disease process. But reaching that goal requires making assumptions like Markov and homogeneity with time. The present study aims to investigate these hypotheses. MATERIALS AND METHODS: Data from 330 patients with gastric cancer undergoing surgery at Iran Cancer Institute from 1995 to 1999 were analyzed. To assess Markov assumption and time homogeneity in modeling transition rates among states of multi-state model, Cox-Snell residuals, Akaikie information criteria and Schoenfeld residuals were used, respectively. RESULTS: The assessment of Markov assumption based on Cox-Snell residuals and Akaikie information criterion showed that Markov assumption was not held just for transition rate of relapse (state 1-state 2) and for other transition rates - death hazard without relapse (state 1-state 3) and death hazard with relapse (state 2-state 3) - this assumption could also be made. Moreover, the assessment of time homogeneity assumption based on Schoenfeld residuals revealed that this assumption - regarding the general test and each of the variables in the model - was held just for relapse (state 1-state 2) and death hazard with a relapse (state 2-state 3). CONCLUSIONS: Most researchers take account of assumptions such as Markov and time homogeneity in modeling transition rates. These assumptions can make the multi-state model simpler but if these assumptions are not made, they will lead to incorrect inferences and improper fitting.

Factors affecting survival of patients with oesophageal cancer: a study using inverse Gaussian frailty models

<p><b>INTRODUCTION</b>Oesophageal cancer is one of the most common causes of cancer mortality in developing countries, including Iran. This study aimed to assess factors affecting survival of patients with oesophageal cancer using parametric analysis with frailty models.</p><p><b>METHODS</b>Data on 359 patients with oesophageal cancer was collected from the Babol Cancer Registry for the period 1990-1991. By 2006, the patients had been followed up for a period of 15 years. Hazard ratio was used to interpret the risk of death. To explore factors affecting the survival of patients, log-normal and log-logistic models with frailty were examined. The Akaike Information Criterion (AIC) was used for selecting the best model(s). Cox regression was not suitable for this patient group, as the proportionality assumption of the Cox model was not satisfied by our data (p = 0.007).</p><p><b>RESULTS</b>Multivariate analysis according to parametric models showed that family history of cancer might increase the risk of death from cancer significantly. Based on AIC scores, the log-logistic model with inverse Gaussian frailty seemed more appropriate for our data set, and we propose that the model might prove to be a useful statistical model for the survival analysis of patients with oesophageal cancer. The results suggested that gender and family history of cancer were significant predictors of death from cancer.</p><p><b>CONCLUSION</b>Early preventative care for patients with a family history of cancer may be important to decrease the risk of death in patients with oesophageal cancer. Male gender may be associated with a lower risk of death.</p>

Preventing Mother-to-Child Transmission of HIV/AIDS: Do Iranian Pregnant Mothers Know about it?

INTRODUCTION: Nowadays, HIV is mostly spreading in Asian countries. One of the important routes for HIV transmission in these countries is the vertical route which infects 35% to 45% of newborns. Mother's education, drug prophylaxis and Cesarean section, accompanied by banning breastfeeding will decrease this rate to 2%. Therefore, mothers' knowledge about Prevention of Mother to Child Transmission (PMTCT) has a great role in HIV/AIDS prevention. This study was designed to evaluate knowledge of pregnant women about HIV, its vertical transmission and prevention in Tehran, Iran. MATERIALS AND METHODS: This cross-sectional study was conducted on 1577 pregnant women aged 15 - 46 years who were attending prenatal care clinics in Tehran, Iran. The research material was a questionnaire which was completed daily by trained midwives. The data were statistically analyzed by ANOVA, independent sample t-test, Pearson correlation and linear regression with a significance level of p = 0.05. RESULTS: About 16.5% of the participants had good knowledge about HIV/AIDS and 54.1% about its transmission routes but awareness about its prevention was only 5.7%. Fifty-seven percent of the participant had not been tested for HIV earlier and 20.2% were not willing to undergo such tests. About 86.2% of the participants had no idea about the availability of drug prophylaxis in Iran for PMTCT. CONCLUSION: The fact that 28.2% of the participants were not willing to undergo HIV testing reflects negative attitude about HIV infection. Although the overall awareness about the infection and its transmission was good but knowledge about its prevention especially by PMTCT and its availability in Iran was low. Educational programs through mass media or prenatal care programs by focusing on HIV/AIDS prevention maybe useful.