Secular trends in all-cause and cause-specific mortality rates in people with diabetes in Hong Kong, 2001-2016: a retrospective cohort study

Aims/hypothesis The aim of the study was to describe trends in all-cause and cause-specific mortality rates in Hong Kong Chinese people with diabetes from 2001 to 2016. Methods The Hong Kong Diabetes Surveillance Database (HKDSD) is a territory-wide diabetes cohort identified from the Hong Kong Hospital Authority electronic medical record system. Deaths between 2001 and 2016 were identified from linkage to the Hong Kong Death Registry. We used Joinpoint regression analysis to describe mortality patterns among people with diabetes by age and sex, and standardised mortality ratios (SMRs) to compare all-cause mortality rates in people with and without diabetes. Results Between 2001 and 2016, a total of 390,071 men and 380,007 women aged 20 years or older with diabetes were included in the HKDSD. There were 96,645 deaths among men and 88,437 deaths among women. Mortality rates for all-cause, cardiovascular disease and cancer among people with diabetes declined by 52.3%, 72.2% and 65.1% in men, respectively, and by 53.5%, 78.5% and 59.6% in women, respectively. Pneumonia mortality rates remained stable. The leading cause of death in people with diabetes has shifted from cardiovascular disease to pneumonia in the oldest age group, with cancer remaining the most common cause of death in people aged 45-74 years. The all-cause SMRs for men declined from 2.82 (95% CI 2.72, 2.94) to 1.50 (95% CI 1.46, 1.54), and for women, they declined from 3.28 (95% CI 3.15, 3.41) to 1.67 (95% CI 1.62, 1.72). However, among people aged 20-44 years, the declines in all-cause mortality rates over the study period were not statistically significant for both men (average annual per cent change [AAPC]: -3.2% [95% CI -7.3%, 1.0%]) and women (AAPC: -1.2% [95% CI -6.5%, 4.4%]). The SMRs in people aged 20-44 years fluctuated over time, between 7.86 (95% CI 5.74, 10.5) in men and 6.10 (95% CI 3.68, 9.45) in women in 2001, and 4.95 (95% CI 3.72, 6.45) in men and 4.92 (95% CI 3.25, 7.12) in women in 2016. Conclusions/interpretation Absolute and relative mortality has declined overall in people with diabetes in Hong Kong, with less marked improvements in people under 45 years of age, calling for urgent action to improve care in young people with diabetes.