Cause and age-related mortality trends in Bangladesh

Background The purpose of this study was to analyze mortality trends in Bangladesh from 2000 to 2008, to identify the main causes of death, and categorize them by sex and age group. Methods This study used vital registration, maternal and child health data collected from Matlab, a rural area of Bangladesh, in 2000, 2004 and 2008.The data were collected and published by Health and Demographic Surveillance System of ICDDR, B. Results This study indicates a downward trend in communicable disease, neonatal and maternal, injury and miscellaneous mortality. Only non-communicable diseases (NCDs) revealed an uprising trend for both males and females. Among the NCDs, circulatory system related diseases were most common in Bangladesh. The second major cause of death was neoplasm. The risk of deaths from non-communicable diseases increased with age. The overall death rates were higher for males than females. Males of ages 45 and above were greatly affected by circulatory system related diseases and neoplasm. Circulatory system related deaths were highest (34.01%) in the 70-79 age group. Neoplasm related deaths were highest (34.38%) in the 60-69 age group. Similar patterns were observed for females. Circulatory system related diseases, respiratory related diseases and neoplasms greatly affected females of the 45-59 and above age group. The highest percentage (38.65%) of circulatory system related deaths was found in the 70-79 age group; neoplasm related deaths were highest (29.41%) in the 45-49 age group; and the highest percentage (32.69%) of respiratory related diseases was found in the 60-69 age group. Conclusions It was observed that a large portion of the population died because of non-communicable diseases. Public awareness about common NCDs and the risk factors involved should be raised. Promoting health-related content both in male and female education can bring improvements in reducing NCDs.


Introduction
Mortality trends are important to demographers because they present a useful way of examining mortality differentials and their principal causes across populations.It has been reported that generally mortality rates in Bangladesh have reduced notably over recent decades 1 .However, deaths caused by chronic diseases are rising at an alarming rate 1 .There is a rapid rise observed in the burden of non-communicable diseases (NCDs) worldwide.Demographic transition and changing lifestyles among people are important factors for these kind of health problems 2 .The World Health Organization (WHO) has predicted that, by 2020, two-thirds of the world's global burden of disease will be caused by noncommunicable conditions 3 .In 2005 it was reported that noncommunicable diseases such as heart disease, stroke, diabetes mellitus, cancer, and chronic respiratory diseases were responsible for 59% of the 57 million deaths yearly and 46% of the total burden of disease, globally 3 .
The burden of NCDs has been showing an increasing trend in South Asia, where almost half of all deaths in Asia and 46% of global burden of disease is attributable to these diseases 5 .It was observed in much of sub-Saharan Africa that the leading risks were those associated with poor quality of life 6 .Cardiovascular disease is a major non-communicable disease, taking almost 17 million lives each year 7 .It has been observed that decreasing primary risk factors such as inadequate nutrition, physical inactivity, smoking etc. can decrease death rate significantly 7 .Alam et al. 8 investigated total deaths of adults with increasing age in Bangladesh and found communicable diseases responsible for 18% of overall deaths and NCDs responsible for 66% 8 .The NCDs included those caused by the circulatory system (35%), respiratory system (10%), digestive system (6%), neoplasms (11%) and endocrine and metabolic disorders (6%) 8 .
There are relatively few published studies about mortality, especially for NCDs, in developing countries like Bangladesh.It is therefore a timely necessity to categorize the country's mortality data by cause of death, sex and age group.The aim of this study is to analyze mortality trends in Bangladesh.These will help in the development of strategies regarding the approach of the health sector to disease control.It is also important to increase awareness about which diseases will cause further burden in Bangladesh, in order to supply the suitable drugs.

Materials and methods
This study used vital registration, maternal and child health data collected from Matlab, a rural area of Bangladesh, in

Ethics approval
The ethical considerations of the study were approved on the 12/06/2012 by the University Research Ethics Committee, University of Rajshahi, Bangladesh.

Consent to participate
All participants were informed about the study and gave their written consent to participate.

Results
Table 1 shows total deaths and death rates in Bangladesh in 2000,  2004, and 2008.Regarding causes of death, neonatal and maternal diseases (D1), showed a decreasing trend both in males and females.Communicable diseases (D2) also showed decreasing It is observed that males have a higher mortality rate than females in 2008.Also, the total number of deaths from noncommunicable diseases was significantly higher than in the rest of the disease categories for both sexes.After analyzing Table 2, it has come to our attention that the percentage of male deaths was higher than female deaths across all years.10).Given that the null hypothesis is rejected when the p-value is less than 0.05, this indicates a strong relationship between age and incidence of disease in females (Table 10).

Discussion
In 1990, worldwide and regional cause-of-death patterns were measured across age groups.It was found that 98% of all deaths in children below 15, 83% of all deaths in the 15-59 age group, and 59% of all deaths in the 70+ age group were occurring in the developing world 9 .The disease mortality pattern in elderly patients of a Nigerian teaching hospital was studied from January 2007 to December 2011.A total of 3,002 elderly (>65 years) people were admitted, of which 561 died.Among the population, 317 were male and the rest were females.Cerebrovascular disease was the top cause of death (25.1%).The second and third major causes of death were malignancies (15.2%) and diabetes mellitus (8%) 10 .A cross-sectional study involving 535 inhabitants of Sokoto in Nigeriato displayed the prevalence and pattern of non-communicable diseases.The participants were overweight, obese and morbidly obese, and represented 12.3%, 6.7% and 0.9% of the population, respectively.The prevalence of pre-hypertension and hypertension was 8.5% and 30.2%, respectively 11 .
Among the total female respondents, 234 (54%) of NCD related deaths in 2004 fall under the category of circulatory related disease, 46 (10%) of them fall in the neoplasm group, and 34 (8%) of them were respiratory related.Then, 51 (12%) female NCD related deaths fall under the category of digestive disease, 29 (6%) under endocrine disorder, 13 (3%) under neuro-psychiatric, 17 (4%) under genito-urinary and 12 (3%) under the other noncommunicable disease category.Among the total female respondents, 282 (61%) of NCD related deaths in 2008 fall under the category of circulatory related disease, 51 (11%) fall in the neoplasm group and 52 (11%) of them were respiratory related.Then, 21 (4%) female NCD related deaths fall under the category of digestive disease, 31 (7%) under endocrine disorder, 8 (2%) under neuro-psychiatric, 13 (3%) under genito-urinary and 5 (1%) under the other non-communicable disease category.There were more male deaths due to neoplasms and more and female deaths due to circulatory related disease.
It is recognized that a huge portion of the population will die because of non-communicable diseases.The number of deaths rapidly increases year by year 12,19

Conclusions
This study recognized that a huge number of people die because of non-communicable diseases.This number increases year by year at a large scale.Deaths from circulatory related diseases were significantly higher than from other non-communicable diseases.
In females, the mortality rate was very high for these.The second major cause of death was from neoplasms for the male population in 2008.Circulatory system related diseases and neoplasms greatly affected the 45-59 age groups and above.For females, the death rate was very high for respiratory related diseases.Females were affected by non-communicable diseases at a younger age than males.Circulatory system related diseases, neoplasms and respiratory related diseases are the top three NCDs which have massive impact on the health of the population, and should therefore be given the utmost attention.These three NCDs and their associated risk factors should be targeted in all public health awareness programs.
The national policy and action plan should take these points into consideration, and focus on improving basic education and expanding public health systems to raise awareness.Mass media outlets such as television, newspapers, radios, and the internet can play an effective role to promote consciousness and alert people to the dangers posed by NCDs.Awareness campaigns can positively modify attitudes.Finally, the Ministry of Health and Family Welfare should train more personnel, achieve national coverage and promote more research on the subject, thus ensuring high standards are kept. 1. 2.
(delete "in") the rest of the disease categories for both sexes".Authors should mention here about statistical analysis before presenting the findings in the result section.
: Cause-Specific mortality rate Definition: delete "of disease" as particular cause can be either disease or injury or accident etc. Formula: it should be "per 1000", not 100 : This article is based on secondary data analysis.Suggestion is "All participants Consent to participate gave their written consent when ICDDR,B collected data for vital registration".
As authors presented their study findings in tables (mainly Table 5 & 6); they do not need to Results: mention the findings of each row and column in text.They should mention only the important findings which they will interpret in the discussion section.Example: the main focus of this manuscript is NCD; in this case, congenital malformations, neuro-psychiatric, digestive disease, genito-urinary are not relevant to highlight in the result section.
Authors repeated their study findings in the 2 , 3 and last part of 4 paragraph which they Discussion: should not do.In this section, they should interpret their results and describe the significance of their study findings by comparing with the findings of other studies.They should do critical analysis of their study findings.In the 1 paragraph, they compared their study findings with a hospital based study where the respondents were elderly patients and this is not relevant as Matlab DHSS is population based.And in the last part of 1 paragraph where they mentioned about a cross sectional study; how this study finding is related to interpret their study findings.
: Author should add this section.In this section, they can mention that they do not Limitation of study have detailed and correct information about causes of death related to NCD; e.g.whether "respiratory disease" is representing only COPD, which is NCD or other respiratory disease.In the similar way, whether "endocrine disorder" includes only diabetes or other endocrine problem like Thyroid disease.In Tables 5 & 6, I did not find the information on 2000 and in Table 7 I did not find the information on "respiratory".Does it mean that these information were not available, if yes, authors should mention in this section.

My minor comments
Authors should avoid repetition; e.g.In the last paragraph of Discussion and first paragraph of Conclusion "huge portion …..year by year"-more or less same meaning.Table 5 is for male, so no need to mention "male 2004" under "Frequency and Percent".Same comment for Table 6 Table 1: could be re-organized.After the column "Total deaths", authors can add the column "Overall rate per thousand" D1 and Rate: These two columns under D1; 1 column is for total number of deaths due to D1 and 2 column is death rate per 1000 due to D1.These two columns can be reorganized  2: authors should delete two digits (.00) after the number of total deaths.They can add one more row for "Total percentage" in addition to "Total deaths"  It is very significant to directly report the mortality trend in developing countries like Bangladesh.The data are from original vital registration and maternal and children health.However authors do not describe the vital registration and maternal and children health collecting systems.How to work of these collecting systems?Who report the status of victims to whom?How many cases are diagnosed by hospital?These basic information are very necessary in the manuscript.Also how about the quality of these collecting system, underreporting, or misreporting?Authors should supplement these messages.
As the number of deaths per year is only about 800, it is understanding why authors classified a bigger age span for mortality.I still suggest mortality aged from 15-59 is divided into 2 groups: 15-39, and 40 -59.In addition authors do not emphasize the total mortality rate is crude death rate or standard death rate, but it should be the standard death rate for comparison with different annual mortality.
The third, the death causes.Authors very briefly define the death causes: D1neonatal and maternal diseases (D1), D2 Communicable diseases, D3: Non-communicable diseases and D4 Injuries and miscellaneous causes.The definition on death causes is hard to satisfy the death causes analysis.Authors should refer to the International classification of death causes, the results of the manuscript can be understood by international colleagues.Especially authors list the subdivision category of chronic non-communication diseases without ICD code in Table 5, so it is hard to understand whether the diseases is same disease on the international category of diseases causes.
No competing interests were disclosed.

Competing Interests:
I have read this submission.I believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.
Rate per 1000 | Total deaths | Rate per 1000 | Total deaths | Rate per 1000 | Total deaths | Rate per 1000 | Table Is the work clearly and accurately presented and does it cite the current literature?PartlyIs the study design appropriate and is the work technically sound?PartlyAre sufficient details of methods and analysis provided to allow replication by others?PartlyIf applicable, is the statistical analysis and its interpretation appropriate?YesAre all the source data underlying the results available to ensure full reproducibility?Yes Are the conclusions drawn adequately supported by the results?Yes No competing interests were disclosed.Competing Interests: Referee Expertise: | I have read this submission.I believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above. of Basica Medical Sciences, Chinese Academy of Medical Sciences, Beijing, China The manuscript' objective is to analyze mortality trends in Bangladesh from 2000 to 2008, to identify the main causes of death, and categorize them by sex and age group with vital registration, maternal and child health data collected from Matlab, a rural area of Bangladesh, in 2000, 2004 and 2008 though main causes of death, and categorize them by sex and age group with vital registration, maternal and child health data collected from Matlab, a rural area of Bangladesh, in 2000, 2004 and 2008 though Health and Demographic Surveillance System of ICDDR, B.

Table 3
The trends remained the same for 2008.This was also true for the age group 15-59.There was no statistically significant difference in death rates between males and females of the age group 0-14.Infant mortality was highest in 2000 amongst this age group, at 15 per thousand both in male and female infants.Female infant mortality exhibited a gradual decline over the years from 2000 to 2008, similar to male infant mortality.Infant mortality rate was 11 per thousand in 2004 and 6 per thousand in 2008.

Table 5
shows that among the total male NCD related deaths in year 2004, 232 (43%) fall under the category of circulatory related disease, 82 (15%) of them fall in the neoplasm group, and 78 (14%) of them were respiratory related.Then, 59 (11%) male NCD related deaths fall under the category of digestive disease, 47 (9%) under

Table 7
shows the distribution by age group of male circulatory and neoplasm related deaths.Circulatory system related diseases and neoplasms greatly affected the age groups 45-59 and above.Circulatory system disease related deaths were highest (34.01%) in the age group 70-79, and neoplasm related deaths were highest (34.38%) in the age group 60-69.The asymptotic significance level was 0.000.Given that the null hypothesis is rejected when the p-value is less than 0.05, this indicates a strong relationship between age and incidence of disease in men.(Table8).Table9shows the distribution by age group of female deaths caused by three major NCDs: circulatory system related diseases, neoplasms, and respiratory related diseases.Similar to what was observed in the male population, circulatory system related diseases, respiratory related diseases, and neoplasms had a greater effect on age groups 45-59 and above.Circulatory system disease related deaths were highest (38.65%) in the age group 70-79, neoplasm related deaths were highest (29.41%) in the age group 45-59 and respiratory related deaths were highest (32.69%) in the age group 60-69.The asymptotic significance level was less than 0.05 (Table