Analysis of the Underlying and Multiple Causes of Death for the Kuwaiti Population 40 years and over in Kuwait ; Part I : Demographics

Background: Improved health care brought about major changes in mortality pattern; life expectancy has increased and the causes of death are more likely to result from chronic diseases, death rarely result from a single cause and the use of the underlying cause of death (UCD) will overlook many of the contributing diseases that are highlighted by multiple cause of death (MCD) analysis. Objective: The paper addresses the demographic and non-clinical variables related to the number of causes recorded in the death certificates notification (DCN). Methods: All the DCN for the Kuwaiti population, 40 years or over for the period 1993-2001 were compiled and all the causes up to five additional causes were recorded. A total of 13960 cases (7966 males and 5994 females), reported in the period 1993-2001, were analyzed. The causes of death were provided according to the WHO ICD9. Results: A single cause (UCD) was reported in 5.6% of the cases, 27.1% had 3 causes and 12.5% had 6 causes. The mean number of causes amounted to 3.64 and 3.8 for the males and females. Variability according to the year was not marked. Those dying in the hospitals had a relatively higher mean number of causes compared to those dying in other places, and this was common to the 2 gender groups. A rising trend was seen with age; with the males the 60-, 70or 80+ age groups had higher mean number of causes compared to the younger groups. With females the means for the 60and 70groups were relatively higher than the other groups, the group 40+ was having lower means compared to the other groups and this was common to the 2 gender groups, particularly with the males. Conclusion: The UCD alone was reported for less than 7% of the causes of death among the Kuwaiti population 40 years or over. Use of multiple cause of death will add a lot of useful information that can be used to highlight several disease conditions not shown by the UCD.


INTRODUCTION
The socioeconomic development of industrialized countries in the 20 th century has brought about a change in the pattern of mortality; first, life expectancy at birth has increased, and second, the major causes of death are currently chronic and long-term diseases with which normally co-exist other diseases. (1)Death rarely results from a single cause and it can be caused by a variety of factors. (2)Causes of death are defined as all the diseases, morbid conditions or injuries, which either resulted in or contributed to death.The underlying cause of death (UCD) is defined as the disease or injury, which initiated the train of events leading eventually to death. (3)By convention UCD is selected as the one that initiated the death process. (4)The multiple causes of death (MCD) are defined as all causes of death mentioned on the death certificate. (5)is model of selection of the UCD presents certain limitations, the major one being that of the arbitrariness of selection of the underlying cause of death if more than one sequence of logical causes exists . (3)alysis based on UCD is useful and relatively simple to tabulate and interpret.It remains the primary tool for many researchers and is adequate for examining many conditions, however, it provides a limited picture of mortality and health of the population. (5).Various authors began to point out that deaths due to chronic diseases were inadequately described by the single UCD statistics, consequently, increasing the difficulties of the epidemiologist.In addition, death certificates include a greater quantity of information, which, as a consequence of the selection of only one cause, is lost, thus, wasting much valuable information provided by the death certificates. (6)rael et al. (7) gave a sort of rallying call for researchers to consider the analytical potential of multiple causes of death.The Australian Bureau of Statistics points out that using multiple cause of death allows researchers to comprehensively understand and track deaths due to other diseases which do not often appear as the underlying cause of death; it provides better documentation on multi-morbid associations and the strength of the association between conditions which led to death, (5) MCD, by considering all diagnosis mentioned in the death certificate, highlights conditions that are underestimated by the UCD, that has traditionally been used in mortality statistics. (9)Certain chronic diseases often increase the risk of other associated long term conditions. (10)day, statistical support provides epidemiologists with the possibility of completing these statistics by additionally counting all the causes which appear in the death certificate (multiple coding).The coding of multiple causes of death adds information about interaction of diseases, number of deaths in which a disease acts as a contributory factor, nature of the lesions in deaths from external causes, and validity of the mortality statistics. (1)MCD can rectify inconsistency of UCD.Bah (11) used a MCD approach to rectify inconsistency between 2 sets of data about maternal mortality in South Africa.MCD can assist in identifying problems with the process of recording and coding cause of death. (12)MCD analysis was also used to look at trends in certain diseases. (13).Mannino et al. (14)

MATERIAL AND METHODS:
To provide better insight into the magnitude of the specific causes of death and their contribution to the mortality pattern Significance was tested by the t or F values as appropriate; a P < 0.05 was considered significant.

RESULTS:
The The means for the 60, and 70 age groups were significantly higher than that for 40 and 50 groups.As for females, the overall mean (3.80± 1.35) was slightly higher than that for the males.The lowest means were those for the 40-and 50 years groups.The mean for the 40 years was significantly lower than that for the 70-and 60-years age groups.

DISCUSSION:
Policies and programs to combat disease and injuries should be based on current timely information about the nature and extent of health problems, their determinants and how the impact of such diseases is changing with respect to both magnitude and distribution in populations. (15)Despite their limitations mortality statistics are the most readily available sources of information on long term trends for many diseases. (16).

Swain et al. stressed the importance of proper filling up of the death certificate;
especially in the era of increasing reliance on evidence-based medicine. (17)e modal number of causes (3) was the same, and the means (3.64) for males and (3.80) females was identical to that reported for Sanitaria in Spain. (18)The mean number of causes of death per certificate was slightly higher than that reported for Brazil (19) where the mean number was 2.81 with an overall range from 2.07 to 3.  (20), that for the US was 2.65 (21) both were slightly lower than that for Kuwait.
A different pattern was reported for South Africa (SA), the first African country to publish multiple causes of death and make them available on the net. (8)The modal number for 2003 and 2004 was one; that is a single cause (22) , the mortality is governed by females. (8)e trend of lower reporting of the causes of death seen in the study period in the US (13) was not seen in the present study.
The mean number of multiple causes according to the sex was almost equal or slightly higher with females.This was in line with reports from Canada, (20) the higher life expectancy with females in Canada may explain the difference.However, the finding in the present study was somewhat different from that reported by Wall et al. (13) who found a slightly higher ratio for males, though the difference was quite small (1% with the method used by Rezende et al. (9) though they put the line at 20 years.The pattern of larger number of mentions with older age was generally in line with that reported for Canada. (20)This was also seen for the United States (7) and Spain. (1)creased reporting of non underlying causes with older age is likely due to the actual differences in the cause of death.
Hospital inpatients, 71.0% for males and 75.3% for females, had the highest probability of reporting multiple cases of death, dying at home or elsewhere was associated with a lower mean number of causes of death and this was common to both the males and females; the differences between the means were highly significant.The higher mean number of causes of death for those dying in the hospitals is similar to that reported by Wall et al., (13) possibly due to a better documentation of disease history, and the more familiarity of the certifier with the dead. (13)25) CONCLUSIONS in a holistic manner, all the DCN for the Kuwaiti population, 40 years or over were compiled and all the causes up to five additional causes were recorded.The DCN Bull High Inst Public Health Vol.39 No.2 [2009] in Kuwait normally show the day, month and year, together with the sex, nationality, age, residence and place of death.A total of 13960 cases (7966 male and 5994 female), which were all those reported in the period 1993-2001, for the nationals 40 years or over were analyzed.The causes of death were provided according to the ICD9.The coding of the cause of death for those who die in the hospitals is done by the attending physician in charge.The physicians are trained by the staff of the Vital and Health Statistic Department at MOH.The coding is done according to WHO rules.Only one cause is mentioned as the UCD.A single person at the Vital and Health Vital Statistics Department is in charge of verifying the DCN and their coding.Statistical manipulations were done by SPSS version 14 for windows.The ratios were computed as percentages and the differences tested by χ 2 , for continuous variable the means ± the SD were computed.