Compound Poisson frailty model with a gamma process prior for the baseline hazard: accounting for a cured fraction.

Cox model and traditional frailty models assume that all individuals will eventually experience the event of interest. This assumption is often overlooked, and situations will arise where it is not realistic. We introduce Compound Poisson frailty model for survival analysis to deal with populations in which some of the individuals will not experience the event of interest. This model assumes that the target population is a mixture of individuals with zero frailty and those with positive frailty. In this paper, we consider a compound Poisson frailty model for right-censored event times from a Bayesian perspective and compute the Bayesian estimator using the Markov Chain Monte Carlo method, where a Gamma process prior is adopted for the baseline hazard function. Furthermore, we evaluate the approach using simulation studies and demonstrate the methodology by analyzing the data from achalasia patient cohort.

The Effect of the COVID-19 Pandemic on Non-Communicable Disease Prevention and Management Services in the Primary Health Care System of Iran.

Background: The COVID-19 pandemic has caused significant disruptions in the provision of non-communicable disease (NCDs) prevention and control services in many countries, and there is a concern that it would lead to long-term complications of the diseases. The aim of this study is to assess the changes in the provisions of selected NCD services before and after the COVID-19 epidemic in Iran's primary healthcare system. Methods: In this descriptive-analytical retrospective study, the number of eight NCD services provided during the first 10 months of the COVID-19 pandemic from Feb 2020 to Dec 2020 were compared with the same period in the previous year using the data from the Iranian integrated electronic health record system (SIB) and also the association between the number of deaths due to COVID-19 and a sample of NCD services were assessed using cross-correlation analysis. The statistical analysis was performed in Stata Software v.14. Results: The NCD services have decreased by an average of 18.89% compared to the same period in the previous year; this decline was much more severe at the beginning of the epidemic period (up to 75% in some services) and was greater in physician-provided services than in non-physician services. Also, examining the course of the selected services during this period, a gradual compensation was evident after the initial reduction. Conclusion: The general trend of the selected services of prevention and control of NCDs in the PHC system of Iran within 10 months after the onset of COVID-19 showed a sharp decline and subsequent gradual compensation. Although the process of compensation in some services may be considered somewhat reassuring, in the case of some essential services, more effort and attention to the implementation of programs or compensatory policies seem necessary.

Assessing the Relationship between Chronic Lymphoid Leukemia Mortality Rates and Human Development Index: A 26-Year Trend Analysis Using Location-Scale Mixed Effects Model.

BACKGROUND: Chronic lymphoid leukemia (CLL) is one of the most prevalent types of leukemia, which is responsible for a remarkable mortality rate in the world. This study aimed to investigate the global trend of this cancer from 1990 to 2015 and to determine the relationship between trend of CLL mortality rate and Human Development Index (HDI) throughout the world. METHODS: The age-standardized mortality rate data of all countries of the world (per 100,000) were extracted from the GBD database. In addition, the HDI values for the studied countries in different years were obtained from the UNDP database. The statistical analysis was performed using the mixed-effects location-scale model in the SAS software, version 9.4. RESULTS: The findings of the statistical modeling showed a downward slope for CLL Age Standardized Mortality Rate (ASMR) for total world countries (ß̂ = -0.002). We also find a significant association between CLL ASMR and HDI. Countries with higher HDI had higher level of CLL ASMR in years 1990 to 2015 with a negative slope. Furthermore, countries with lower HDI had Lower level of CLL ASMR with rather fixed rates in this period. CONCLUSION: These findings showed a decreasing trend of global CLL ASMR in the previous decades, although, the fixed trend of CLL ASMR in countries with low HDI is worrisome. The health policymakers should make more efforts to decrease the mortality due to this cancer in these countries.

Cardiovascular disease mortality and years of life lost attributable to non-optimal systolic blood pressure and hypertension in northeastern Iran.

BACKGROUND: High blood pressure is the second most important risk factor of cardiovascular diseases (CVDs) in Iran. It is imperative to estimate the burden of CVDs that can be averted if high blood pressure is controlled at the population level. The aim of the current study was to estimate the avertable CVD mortality in the setting of Golestan Cohort Study (GCS). METHODS: Over 50,000 participants were recruited and followed for a median of 7 years. The exposures of interest in this study were non-optimal systolic blood pressure (SBP) and hypertension measured at baseline. Deaths by cause have been precisely recorded. The Population Attributable Fraction (PAF) of deaths and Years of Life Lost (YLLs) due to CVDs attributable to exposures of interest were calculated. RESULTS: Overall, 223 deaths due to ischemic heart disease (IHD), 207 deaths due to cerebrovascular accidents (CVA), and 460 deaths due to all CVDs could be averted if the SBP of all subjects in the study were optimal. Similarly, 5,560 YLLs due to IHD, 4,771 YLLs due to CVA, and 11,135 YLLs due to CVDs could be prevented if SBP were optimal. In all age groups, the avertable deaths and YLLs were higher due to IHD compared with CVA. Deaths and YLLs attributable to non-optimal SBP in women were less than men. CONCLUSIONS: A very large proportion of CVD deaths can be averted if blood pressure is controlled in Iran. Effective interventions in primary and secondary health care setting are mandatory to be implemented as early as possible.

Direct Sequencing of Cyclooxygenase-2 (COX-2) Revealed an Intronic Variant rs201231411 in Iranian Patients with Pancreatic Cancer.

BACKGROUND There are hoarding documents for the biological importance of cyclooxygenase-2 (COX-2) in pancreatic carcinogenesis. We aimed to thoroughly investigate the DNA sequence variations of whole COX-2 exons in a large case-control study of pancreatic cancer by direct sequencing. METHODS The entire exonic regions of COX-2 including 10 exons were sequenced in the germline DNA of 96 patients with pancreatic cancer. Selected variants within exons six to seven (E6E7) amplicon from the test panel were genotyped in 96 controls. RESULTS The COX-2 gene was demonstrated to be genetically conserved. Four missense mutations were found in three cases. However the common variant c.724-10_724-7delATTT (rs201231411) that is located in intron 6, showed significant difference between cases and controls (21 [21.9%] vs 11 [%11.5], p=0.05). CONCLUSION This study determined that COX-2 has a conservative sequence, which is required for its enzymatic activity and supports the important role of this enzyme's expression in pancreatic cancer rather than any changes in its activity. The effect of intronic variant rs201231411 on COX-2 expression could be analyzed in future studies.