Methods

DisMod II, a software programme, was used to estimate the number of deaths attributable to diabetes in the year 2007 in persons 20-79 years old. The programme was developed for the Global Burden of Disease 2000 study   1 , and is based on a set of differential equations that describe age-specific incidence, remission, case fatality (or relative risk on total mortality), ‘all other causes’ mortality, prevalence and disease-specific mortality. DisMod II implements exact mathematical solutions of these equations. The input data in this study were:

  • Number of persons by 10-year age and sex groups for each country for the year 2007 (UN population projections).
  • Expected number of all deaths in each country, by 10-year age stratum and gender (by applying the age and sex-specific mortality rate for the year 2001 to the population of the year 2007).
  • Estimates of diabetes prevalence by 10-year age and sex groups for each country for the year 2007 (see Diabetes).
  • Remission (equal to zero) and age and sex-specific relative risks of mortality.
  • Remission of diabetes (equal to zero).
  • Relative risk of dying for persons with diabetes compared to those without diabetes, from population-based follow-up studies (see Table 4.1). The published studies were from USA   2  and Taiwan   3 . The unpublished relative risks of death by age and sex were obtained by personal communication from investigators of the DECODE and DECODA studies   4   5 .

DisMod was used to calculate the number of excess deaths that could be attributed to diabetes in each region, i.e. the number of deaths among those with diabetes over and above those expected according to underlying mortality rates. Given that the diabetes-specific variables in the computer model are the prevalence, remission and relative risk of death, DisMod II smoothes out the age-specific relative risks of death available from the different studies (see Table 4.1) and calculates what proportion of all deaths is attributable to diabetes using a simple formula for population-attributable fraction   6 .

1.Barendregt,J.J. Van Oortmarssen,G.J. Vos,T. Murray,C.J. A generic model for the assessment of disease epidemiology: the computational basis of DisMod II. Popul Health Metr.2003; 1(1): 4-
2.Gu,K. Cowie,C.C. Harris,M.I. Mortality in adults with and without diabetes in a national cohort of the U.S. population, 1971-1993. Diabetes Care.1998; 21(7): 1138-1145
3.Tseng,C.H. Mortality and causes of death in a national sample of diabetic patients in Taiwan. Diabetes Care.2004; 27(7): 1605-1609
4.The DECODE study group Is the current definition for diabetes relevant to mortality risk from all causes and cardiovascular and noncardiovascular diseases?. Diabetes Care.2003; 26(3): 688-696
5.Nakagami,T. Hyperglycaemia and mortality from all causes and from cardiovascular disease in five populations of Asian origin. Diabetologia.2004; 47(3): 385-394
6.Miettinen,O.S. Proportion of disease caused or prevented by a given exposure, trait or intervention. Am J Epidemiol.1974; 99(5): 325-332

contents

browse