Multivariate Longitudinal Assessment of Kidney Function Outcomes on Graft Survival after Kidney Transplantation Using Multivariate Joint Modeling Approach: A Retrospective Cohort Study.

Background: The performance of a transplanted kidney is evaluated by monitoring variations in the value of the most important markers. These markers are measured longitudinally, and their variation is influenced by other factors. The simultaneous use of these markers increases the predictive power of the analytical model. This study aimed to determine the simultaneous longitudinal effect of serum creatinine and blood urea nitrogen (BUN) markers, and other risk factors on allograft survival after kidney transplantation. Methods: In a retrospective cohort study, the medical records of 731 renal transplant patients, dated July 2000 to December 2013, from various transplant centers in Mashhad (Iran) were examined. Univariate and multivariate joint models of longitudinal and survival data were used, and the results from both models were compared. The R package joineRML was used to implement joint models. P values <0.05 were considered statistically significant. Results: Results of the multivariate model showed that allograft rejection occurred more frequently in patients with elevated BUN levels (HR=1.68, 95% CI: 1.24-2.27). In contrast, despite a positive correlation between serum creatinine and allograft rejection (HR=1.49, 95% CI: 0.99-2.22), this relationship was not statistically significant. Conclusion: Results of the multivariate model showed that longitudinal measurements of BUN marker play a more important role in the investigation of the allograft rejection.

Improving Fraud and Abuse Detection in General Physician Claims: A Data Mining Study.

BACKGROUND: We aimed to identify the indicators of healthcare fraud and abuse in general physicians' drug prescription claims, and to identify a subset of general physicians that were more likely to have committed fraud and abuse. METHODS: We applied data mining approach to a major health insurance organization dataset of private sector general physicians' prescription claims. It involved 5 steps: clarifying the nature of the problem and objectives, data preparation, indicator identification and selection, cluster analysis to identify suspect physicians, and discriminant analysis to assess the validity of the clustering approach. RESULTS: Thirteen indicators were developed in total. Over half of the general physicians (54%) were 'suspects' of conducting abusive behavior. The results also identified 2% of physicians as suspects of fraud. Discriminant analysis suggested that the indicators demonstrated adequate performance in the detection of physicians who were suspect of perpetrating fraud (98%) and abuse (85%) in a new sample of data. CONCLUSION: Our data mining approach will help health insurance organizations in low-and middle-income countries (LMICs) in streamlining auditing approaches towards the suspect groups rather than routine auditing of all physicians.

Assessing misdiagnosis of relapse in patients with gastric cancer in Iran cancer institute based on a hidden Markov multi-state model.

BACKGROUND: Accurate assessment of disease progression requires proper understanding of natural disease process which is often hidden and unobservable. For this purpose, disease status should be clearly detected. But in most diseases it is not possible to detect such status. This study, therefore, aims to present a model which both investigates the unobservable disease process and considers the error probability in diagnosis of disease states. MATERIALS AND METHODS: Data from 330 patients with gastric cancer undergoing surgery at the Iran Cancer Institute from 1995 to 1999 were analyzed. Moreover, to estimate and assess the effect of demographic, diagnostic and clinical factors as well as medical and post-surgical variables on transition rates and the probability of misdiagnosis of relapse, a hidden Markov multi-state model was employed. RESULTS: Classification errors of patients in alive state without a relapse (e21) and with a relapse (e12) were 0.22 (95% CI: 0.04-0.63) and 0.02 (95% CI: 0.00-0.09), respectively. Only variables of age and number of renewed treatments affected misdiagnosis of relapse. In addition, patient age and distant metastasis were among factors affecting the occurrence of relapse (state1→state2) while the number of renewed treatments and the type and extent of surgery had a significant effect on death hazard without relapse (state2→state3) and death hazard with relapse (state2→state3). CONCLUSIONS: A hidden Markov multi-state model provides the possibility of estimating classification error between different states of disease. Moreover, based on this model, factors affecting the probability of this error can be identified and researchers can be helped with understanding the mechanisms of classification error.

Association of residential segregation and disability: a multilevel study using Iranian census data.

The association of racial segregation and health outcomes has been reviewed recently in the literature, but the health effect of other contexts of segregation with respect to residential environment has not as yet been fully reviewed. Besides, most of the literature on segregation has been performed in Western countries. Here, we undertake a multilevel analysis of residential segregation of socioeconomic and demographic factors and disability rate in an Eastern developing country in order to elucidate the effects of this aspect of segregation on disability rate. The latest Iranian national census in 2006 was used to measure segregation indices and perform the analysis. Information theory index and its ordinal form were applied to measure evenness dimension of segregation of categorical and ordinal variables, respectively. Segregation of contextual and structural characteristics of residential environment, which are important determinants of socioeconomic status in Iran, had different relations with disability rate. Provinces which were segregated by type of occupation of residents, sex, and ownership of a motorcycle had a lower individual disability rate, while age segregation and house ownership had a positive effect on the rate of individual disability in the province. The findings also showed that almost all the aforementioned segregation indices had the same effect on the rate of family disability. The unique contribution of this study is that it considers how segregation with respect to aspects of social characteristics other than race affects health outcomes. Further studies in this regard may reveal new insights into health outcome inequalities.

The spatial distribution of esophageal and gastric cancer in Caspian region of Iran: an ecological analysis of diet and socio-economic influences.

Recent studies have suggested a systematic geographic pattern of esophageal cancer (EC) and gastric cancer (GC) incidence in the Caspian region of Iran. The aims of this study were to investigate the association between these cancers and the region's dietary and socioeconomic risk factors and to map EC and GC after adjustment for the risk factors and the removal of random and geographic variations from area specific age standardised incidence ratios (SIRs). We obtained cancer data from the Babol cancer registry from 2001 to 2005, socioeconomic indices from the Statistical Centre of Iran, and dietary patterns from the control group in a case control study conducted in the study region. Regression models were fitted to identify significant covariates, and clusters of elevated rates were identified. We found evidence of systematic clustering for EC and GC in men and women and both sexes combined. EC and GC SIRs were lower in urban areas, and were also lower in areas of high income. EC SIRs were lower in areas with higher proportions of people having unrestricted food choice and higher in areas with higher proportions of people with restricted food choice. EC and GC were associated with aggregated risk factors, including income, urbanisation, and dietary patterns. These variables represent the influence of improved lifestyle which has coincided with a decrease in upper gastrointestinal cancer frequency over recent decades but which has not necessarily been uniform throughout the region.

Flash flood preparedness in Golestan province of Iran: a community intervention trial.

OBJECTIVE: To evaluate effectiveness of a community-based preparedness program for flash floods. DESIGN: A controlled community intervention trial with preassessment and postassessment. SETTING: Fifteen intervention villages and 16 control villages in Golestan province of Iran. PARTICIPANTS: People more than six years of age. INTERVENTION: Intervention program consisted assembling Village Disaster Taskforces (VDTs), training of VDTs and community, evacuation drill, and program monitoring. MAIN OUTCOME MEASURES: Individual participation in household preparedness actions including, preparedness meeting, risk mapping, preparation of emergency supplies, assisting vulnerable people, and evacuation drill. RESULTS: Our intervention improved preparedness of local community for flash floods in term of all interested outcome measures. For instance, adjusted odds ratio for participation in an evacuation drill in intervention area in postassessment compared with preassessment was 29.05 (95% confidence interval [CI]: 21.77-38.76), whereas in control area it was 2.69 (95% CI: 1.96-3.70). Difference in these odds ratios was statistically significant (p < 0.001). Participation in a family preparedness meeting and risk mapping were helpful in motivating individuals to take other preparedness actions. Women were found prepared as much as the men. Younger people showed lower participation in preparation of family emergency supplies but higher attendance in evacuation drills. Participation in evacuation drills decreased with increasing age. It was a positive association between risk perception and taking all preparedness actions. CONCLUSION: Flood preparedness programs should focus on participatory risk assessment and preparedness techniques, strive to improve risk perception and female capabilities, and ensure providing assistance to the older people during evacuation.

Correlates of mammography utilization among working Muslim Iranian women.

Most countries in Middle East have been successful in establishing and furthering basic facilities for screening, diagnosis, and treatment of breast cancer. The rate of compliance with mammography screening, however, remains well below North American and Western European countries. We utilized the Health Belief Model (HBM) to explore factors associated with mammography screening behavior among a sample of 320 Muslim women aged > or = 35. Carrying out this cross-sectional study, we found that screening behavior was associated with older age, higher perceived benefit of breast cancer screening, and lower perceived barrier. Additionally, we demonstrate the importance of religious beliefs in influencing mammography screening behavior and explaining the link between religious involvement and mammography behavior.