Quantifying years of life lost in Australia: a multiple cause of death analysis.

Background: Deaths in Australia and other high-income countries increasingly involve multiple conditions. However, key burden of disease measures typically only use the underlying cause of death (UC). We quantified sex and cause-specific years of life lost (YLL) based on UC compared with a method integrating multiple causes of death.

Methods: Causes of death for all deaths in Australia (2015-17), mapped to 136 groups based on International Classification of Diseases 10th revision (ICD-10), were ascribed using (1) the UC only and (2) a multiple cause weighting (WT) strategy. Applying the Global Burden of Disease 2010 life table, YLLUC and YLLWT rates were calculated for each sex and cause of death and compared using relative and absolute measures.

Results: All-cause YLL rates were 113.4/1000 for males and 79.9/1000 for females. Cancers, cardiovascular diseases, external causes, respiratory diseases and nervous system diseases were the five biggest contributors to YLL for each method. For the top 20 causes combined, YLLWT rates were 10% lower for males (YLLWT = 74.93/1000 vs YLLUC = 67.38/1000) and 7% lower for females (YLLWT = 51.34/1000; YLLUC = 47.90/1000); YLLWT rates were lower for ischaemic heart disease and all cancers, but higher for diabetes and dementia, and for chronic obstructive pulmonary disease in males. With multiple cause weighting, renal failure emerged among the top 20 causes of YLL, as did atrial fibrillation and hypertension among females. YLLWT rates for substance abuse, mood disorders, hypertension and schizophrenia were relatively high compared with YLLUC.

Conclusion: The YLLWT metric highlights epidemiologically important conditions that are less often selected as the UC.