Biostatistics - Epidemiology

 Ibrahim Alghamdi

Subtitle

                                             My published articles                                       مقالاتي العلمية المنشورة

Research Title: The incidence rate of female breast cancer in Saudi Arabia: an observational descriptive epidemiological analysis of data from Saudi Cancer Registry 2001-2008

Background: This study presents descriptive epidemiological data related to breast cancer cases diagnosed from 2001 to 2008 among Saudi women, including the frequency and percentage of cases, the crude incidence rate (CIR), and the age-standardized incidence rate (ASIR), adjusted by the region and year of diagnosis.

Methods: This is a retrospective descriptive epidemiological study of all Saudi female breast cancer cases from 2001 to 2008. The statistical analyses were conducted using descriptive statistics, a linear regression model, and analysis of variance with the Statistical Package for the Social Sciences version 20.0.

Results: A total of 6,922 female breast cancer cases were recorded in the Saudi Cancer Reg­istry from 2001 to 2008. The highest overall percentages (38.6% and 31.2%) of female breast cancer cases were documented in women who were 30–44 and 45–59 years of age, respectively. The eastern region of Saudi Arabia had the highest overall ASIR, at 26.6 per 100,000 women, followed by Riyadh at 20.5 and Makkah at 19.4. Jazan, Baha, and Asir had the lowest average ASIRs, at 4.8, 6.1, and 7.3 per 100,000 women, respectively. The region of Jouf (24.2%; CIR 11.2, ASIR 17.2) had the highest changes in CIR and ASIR from 2001 to 2008. While Qassim, Jazan, and Tabuk recorded down-trending rates with negative values.

Conclusion: There was a significant increase in the CIRs and ASIRs for female breast cancer between 2001 and 2008. The majority of breast cancer cases occurred among younger women. The region of Jouf had the greatest significant differences of CIR and ASIR during 2001 to 2008. Jazan, Baha, and Najran had the lowest average CIRs and ASIRs of female breast cancer, whereas the linear trend upward is a concern in certain regions, such as the eastern region, Makkah, and Riyadh. However, further analytical epidemiological research is needed to identify the potential risk factors involved in the increase in the prevalence of breast cancer among Saudi women.

 

Link: http://www.dovepress.com/articles.php?article_id=14713

 

Research Title: The incidence rate of prostate cancer in Saudi Arabia: an observational descriptive epidemiological analysis of data from the Saudi Cancer Registry 2001-2008

Background: This study presents descriptive epidemiological data related to prostate cancer cases diagnosed from 2001 to 2008 among Saudi men, including the frequency and percentage of cases, the crude incidence rate (CIR) and the age-standardised incidence rate (ASIR) adjusted by region and year of diagnosis.

Methods: This is a retrospective descriptive epidemiological analysis of all Saudi prostate cancer cases recorded in the Saudi Cancer Registry (SCR) between January 2001 and December 2008. Statistical analyses were conducted using descriptive statistics, the Poisson regression model, a simple linear regression model and analysis of variance with the Statistical Package for the Social Sciences version 20.0 (SPSS).

Results: A total of 1739 cases were registered in the SCR between January 2001 and December 2008. The eastern region of Saudi Arabia had the highest overall ASIR at 10.1 per 100,000 men, followed by Riyadh at 7.1 and Makkah at 5.2, while Jizan and Najran had the lowest average ASIRs at 1.4 and at 2.0, respectively. The Poisson regression model for the region of Jizan shows that the incidence rate ratio (IRR) was significantly higher (p < 0.001); for the regions of Riyadh at 3.43 times (95% CI, 3.13–3.73), followed by Makkah at 2.56 (95% CI, 2.38–2.74) and the eastern province at 1.93 (95% CI, 1.64–2.23). The annual prediction of the CIR of prostate cancer in Saudi Arabia could be defined by the equation 1.53 + (0.094 · Years), and the prediction of the ASIR could be defined by the equation 2.98 + (0.182 · Years).

Conclusion: There was a steady increase in the CIRs and ASIRs for prostate cancer between 2001 and 2008. The eastern region, Riyadh and Makkah had the highest overall ASIR in Saudi Arabia. Further effective screening programmes and active treatment measures are needed to control prostate cancer disease among Saudi men.

Link: http://www.ncbi.nlm.nih.gov/pubmed/24239850 

 

Research Title: The incidence rate of corpus uteri cancer among females in Saudi Arabia: an observational descriptive epidemiological analysis of data from Saudi Cancer Registry 2001–2008

Background: The present study reviews the epidemiological data on corpus uteri cancer among Saudi women, including its frequency, crude incidence rate, and age-standardized incidence rate (ASIR), adjusted by region and year of diagnosis.

Methods: A retrospective, descriptive epidemiological analysis was conducted of all the corpus uteri cancer cases recorded in the Saudi Cancer Registry between January 2001 and December 2008. The statistical analyses were performed using descriptive statistics, analysis of variance, Poisson regression, and a simple linear model.

Results: A total of 1,060 corpus uteri cancer cases were included. Women aged 60–74 years of age were most affected by the disease. The region of Riyadh in Saudi Arabia had the highest overall ASIR, at 4.4 cases per 100,000 female patients, followed by the eastern region, at 4.2, and Makkah, at 3.7. Jazan, Najran, and Qassim had the lowest average ASIRs, ranging from 0.8 to 1.4. A Poisson regression model using Jazan as the reference revealed that the corpus uteri cancer incidence rate ratio was significantly higher for the regions of Makkah, at 16.5 times (95% confidence interval [CI]: 8.0–23.0), followed by Riyadh, at 16.0 times (95% CI: 9.0–22.0), and the eastern region, at 9.9 times (95% CI: 5.6–17.6). The northern region experienced the highest changes in ASIRs of corpus uteri cancer among female Saudi patients between 2001 and 2008.

Conclusion: There was a slight increase in the crude incidence rates and ASIRs for corpus uteri cancer in Saudi Arabia between 2001 and 2008. Older Saudi women were most affected by the disease. Riyadh, the eastern region, and Makkah had the highest overall disease ASIRs and incidence rate ratios, while Jazan, Najran, and Qassim had the lowest rates. Finally, the northern region experienced the greatest changes in ASIR during the studied period. Further analytical studies are necessary to determine potential risk factors of corpus uteri cancer among female Saudi patients

Link: http://www.dovepress.com/articles.php?article_id=15648 

 

Research Title: Incidence rate of ovarian cancer cases in Saudi Arabia: an observational descriptive epidemiological analysis of data from Saudi Cancer Registry 2001–2008

Purpose: This study provides descriptive epidemiological data, such as the percentage of cases diagnosed, crude incidence rate (CIR), and age-standardized incidence rate (ASIR) of ovarian cancer in Saudi Arabia from 2001–2008.

Patients and methods: A retrospective descriptive epidemiological analysis of all ovarian cancer cases recorded in the Saudi Cancer Registry (SCR) from January 2001–December 2008 was performed. The data were analyzed using descriptive statistics, analysis of variance tests, Poisson regression, and simple linear modeling.

Results: A total of 991 ovarian cancer cases were recorded in the SCR from January 2001–De­cember 2008. The region of Riyadh had the highest overall ASIR at 3.3 cases per 100,000 women, followed by the Jouf and Asir regions at 3.13 and 2.96 cases per 100,000 women. However, Hail and Jazan had the lowest rates at 1.4 and 0.6 cases per 100,000 women, respectively. Compared to Jazan, the incidence rate ratio for the number of ovarian cancer cases was significantly higher (P,0.001) in the Makkah region at 6.4 (95% confidence interval [CI]: 4.13–9.83), followed by Riyadh at 6.3 (95% CI: 4.10–9.82), and the eastern region of Saudi Arabia at 4.52 (95% CI: 2.93–6.98). The predicted annual CIR and ASIR for ovarian cancer in Saudi Arabia could be defined by the equations 0.9 + (0.07× years) and 1.71 + (0.09× years), respectively.

Conclusion: We observed a slight increase in the CIRs and ASIRs for ovarian cancer in Saudi Arabia from 2001–2008. Riyadh, Jouf, and Asir had the highest overall ASIR, while Jazan and Hail had the lowest rates. Makkah, Riyadh, and the eastern region of Saudi Arabia had the high­est incidence rate ratio for the number of ovarian cancer cases. Further analytical studies are required to determine the potential risk factors of ovarian cancer among Saudi women. 

Link: http://www.ncbi.nlm.nih.gov/pubmed/25028565 

 

Research Title: Incidence rate of non-Hodgkin’s lymphomas among males in Saudi Arabia: an observational descriptive epidemiological analysis of data from the Saudi Cancer Registry, 2001–2008

Background: This study describes epidemiological data of non-Hodgkin’s lymphoma (NHL) diagnosed from 2001 to 2008 among Saudi men.

Materials and methods: Retrospective data from all NHL cancer cases among Saudi men recorded in the Saudi Cancer Registry (SCR) between January 2001 and December 2008 were used. Descriptive statistics, analysis of variance, Poisson regression, and simple linear regres­sion were also used.

Results: In total, 2,555 new cases of NHL were recorded between January 2001 and December 2008. The region of Riyadh, Saudi Arabia had the highest overall age-standardized incidence rate (ASIR) at 7.8, followed by the Eastern region at 6.8, and Makkah at 6.1 per 100,000 men; however, Jazan, Hail, and Baha had the lowest average ASIRs at 2.5, 3.7, and 3.9 per 100,000 men, respectively. The incidence-rate ratio for the number of NHL cases was signifi­cantly higher in Riyadh (4.68, 95% confidence interval [CI] 4.11–5.32), followed by Makkah (4.47, 95% CI 3.94–5.07), and the Eastern region of Saudi Arabia (3.27, 95% CI 2.90–3.69) than that in the reference region of Jazan. Jouf had the highest changes in the ASIRs of NHL among Saudi men from 2001 and 2008 (5.0 per 100,000 men).

Conclusion: A significant increase in the crude incidence rate and ASIR for NHL in Saudi Arabia between 2001 and 2008 was found. Riyadh, the Eastern region, and Makkah had the highest overall ASIR in Saudi Arabia. Jazan, Hail, and Baha had the lowest rates. Additionally, Riyadh, Makkah, and the Eastern region had the highest incidence-rate ratio for the number of NHL cases. Finally, Jouf had the highest changes in crude incidence rate and ASIR from 2001 to 2008. Further analyti­cal studies are needed to determine the potential risk factors of NHL among Saudi men 

Link:  http://www.ncbi.nlm.nih.gov/pubmed/25028562 

 

 Research Title: The Incidence Rate of Thyroid Cancer Among Women in Saudi Arabia: An Observational Descriptive Epidemiological Analysis of Data from Saudi Cancer Registry 2001–2008

Abstract: This study provides a descriptive epidemiological data of thyroid cancer cases diagnosed from 2001 to 2008 among Saudi women, including the frequency and percentage of cases, the crude incidence rate (CIR) and the age-standardised incidence rate (ASIR) stratified by the region and year of diagnosis. This is a retrospective descriptive epidemiological analysis of all Saudi thyroid cancer cases recorded in the Saudi Cancer Registry (SCR) between January 2001 and December 2008. The statistical analyses were applied using descriptive statistics with the Statistical Package for the Social Sciences version 20.0. A total of 2,930 cases were recorded in the SCR between January 2001 and December 2008. The region of Riyadh in Saudi Arabia had the highest overall ASIR at 9.43 per 100,000 women, followed by Tabuk at 7.11 and eastern region at 6.5, while Jazan and Jouf had the lowest average ASIRs at 1.97 and at 2.72, respectively. The region of Qassim recorded the greatest changes of ASIR at 5.5 per100,000 women from 2001 to 2008. There was a slight increase in the CIRs and ASIRs for thyroid cancer in Saudi Arabia between 2001 and 2008. Riyadh, Tabuk and eastern region were the highest overall ASIR in Saudi Arabia. While, Jazan and Hail had the lowest rates. Finally, the region of Qassim had the highest changes in CIR and ASIR from 2001 to 2008. Further analytical studies are needed to determine the potential risk factors of thyroid cancer disease among Saudi women. 

 Link:http://www.ncbi.nlm.nih.gov/pubmed/24859807

 

Research Title: The incidence of leukemia in Saudi Arabia: Descriptive epidemiological analysis of data from the Saudi Cancer Registry (2001-2008)

Objectives: To describe the epidemiological data of leukemia cases diagnosed from 2001 to 2008 among male and female Saudis, including the frequency and percentage of cases, the crude incidence rate (CIR), and the age-standardized incidence rate (ASIR) stratified by leukemia subtype, region, and year of diagnosis.

Methods: This is a retrospective descriptive epidemiological analysis of all Saudi leukemia cases recorded in the Saudi Cancer Registry (SCR) between January 2001 and December 2008. The study was carried out in 2013 to investigate the pattern of leukemia in the Saudi population. Descriptive statistics and Poisson regression model were used.

Results: A total of 3852 leukemia cases were registered in the SCR between January 2001 and December 2008. The region of Riyadh, Saudi Arabia had the highest overall ASIR among Saudi males at 5.2 per 100,000 males, followed by both the Eastern region and Northern region at 4.9 per 100,000 males. Furthermore, the region of Najran recorded the highest overall ASIR among Saudi females at 4.5 per 100,000 females. However, Jazan had the lowest average ASIRs of leukemia in Saudi Arabia.

Conclusion: There was a slight increase in the CIRs and ASIRs of leukemia in Saudi Arabia between 2001 and 2008. Riyadh, the Eastern region, and the Northern region had the highest overall ASIRs of leukemia among Saudi males, and Najran had the highest overall ASIRs of leukemia among Saudi females; while Jazan had the lowest rates among the Saudi population.

 

Link: http://www.ncbi.nlm.nih.gov/pubmed/25028223

 

Research Title: The pattern of Middle East respiratory syndrome coronavirus in Saudi Arabia: a descriptive epidemiological analysis of data from the Saudi Ministry of Health

Purpose: This study describes the epidemiology of Middle East respiratory syndrome coronavirus (MERS-CoV) in Saudi Arabia

Patients and methods: Epidemiological analysis was performed on data from all MERS-CoV cases recorded by the Saudi Ministry of Health between June 6, 2013 and May 14, 2014. The frequency of cases and deaths was calculated and adjusted by month, sex, age group, and region. The average monthly temperature and humidity of infected regions throughout the year was also calculated

Results: A total of 425 cases were recorded over the study period. The highest number of cases and deaths occurred between April and May 2014. Disease occurrence among men (260 cases [62%]) was higher than in women (162 cases [38%]), and the case fatality rate was higher for men (52%) than for women (23%). In addition, those in the 45–59 years and 60 years age groups were most likely to be infected, and the case fatality rate for these people was higher than for other groups. The highest number of cases and deaths were reported in Riyadh (169 cases; 43 deaths), followed by Jeddah (156 cases; 36 deaths) and the Eastern Region (24 cases; 22 deaths). The highest case fatality rate was in the Eastern Region (92%), followed by Medinah (36%) and Najran (33%). MERS-CoV infection actively causes disease in environments with low relative humidity (20%) and high temperature (15°C–35°C)

Conclusion: MERS-CoV is considered an epidemic in Saudi Arabia. The frequency of cases and deaths is higher among men than women, and those above 45 years of age are most affected. Low relative humidity and high temperature can enhance the spread of this disease in the entire population. Further analytical studies are required to determine the source and mode of infection in Saudi Arabia

 

Link: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4149400/

 

Research Title: 

The power of the age standardized incidence rate to discover the gene link between cancer diseases: development of a new epidemiological method to save money, time, and effort for genetic scientists

Background: This study provides an incipient epidemiological rule using the concept of direct method of standardization to determine the genetic link between cancer diseases.

Methods: The overall 8 or 10 years age standardized incidence rate (ASIR) for both cancer diseases, for example (A) and (B) should be calculated for all regions of the country. A line chart should be used to display the overall ASIR trend of both diseases (A and B). Pearson’s correlation can be used to determine the strength of the association between the overall ASIRs of both diseases. The overlap or opposite direction of the overall ASIR trend of both diseases (A and B) should be determined and studied for possible associations between cancer diseases.

Results: If the trend of the overall 8 or 10 years ASIR of a disease (A) follows that of disease (B) in all regions of the country, then the genes of patients with both diseases (A and B) will be highly homogeneous, and they should be studied in the region with the highest and lowest overall ASIR for both diseases (A and B). In addition, if there is an opposite direction or overlapping trend for both diseases (A and B) in certain regions of the country or among specific groups of people with the same demographic characteristics, then the genes of patients will be investigated for both diseases to identify the potential gene link between cancer diseases.

Conclusion: This study revealed that the overall ASIR trends of female breast cancer, prostate cancer, and ovarian cancer are very similar in all regions of Saudi Arabia and England. Our epidemiological evidence helps to save money, time, and effort for testing the potential gene link between cancer diseases.

 

Link: http://dx.doi.org/10.2147/OTT.S75785

 

 Research Title: Early marriage is a potential risk factor for female breast cancer in the Eastern Region of Saudi Arabia

Abstract:

This study investigates the potential risk factors of female breast cancer in the eastern region of Saudi Arabia. It is a hospital-based case control study of all Saudi women who were diagnosed with breast cancer during the period from 2010 to 2011. It includes 225 cases and 450 age-matched controls. The statistical analyses were conducted using descriptive statistics, the Student Sample t-test, the Mann-Whitney U test, Chi square test and matched logistic regression model. The factor of early marriage or early sexual intercourse, that is, for females under 18 years of age (OR = 13.9, 95% CI, 6.0 to 32.3), was the strongest risk factor for breast cancer among women in the eastern region of Saudi Arabia; this was followed by the factors of obesity with a high body mass index (BMI) greater than or equal to 30 (OR = 5.7, 95% CI, 2.53 to 13.0); and prolonged use of birth control pills ≥ 36 months (OR = 5.0, 95% CI, 2.13 to 11.8). This study concluded that early marriage is the strongest potential risk factor for female breast cancer among Saudi women. Therefore, it is recommended to increase family awareness and knowledge about the suitable age for marriage.


Link: http://www.usa-journals.com/wp-content/uploads/2012/11/Alghamdi.pdf