These researchers analysed nationally linked data for all publicly funded health expenditure (including hospitalisation, outpatient, pharmaceutical, laboratory testing, and primary care) on 6 noncommunicable diseases (NCDs) listed as cancer, CVD, diabetes, musculoskeletal, neurological, and chronic lung, liver, or kidney disease, for New Zealand adults between 1 July 2007 and 30 June 2014. The data yielded 18.9 million person-years and a total health expenditure of $US26.4 billion ($US calculated in 2016). The analysis compared the costs of having ≥2 NCDs versus those expected from the independent costs of each NCD. It also disaggregated total health spending by NCDs across age and by sex. Around two-thirds (59%) of health expenditure was on NCDs and nearly one-quarter (23.8%) of all health expenditure on chronic NCDs was explained by costs relating to ≥2 diseases (i.e. costs due to comorbid conditions, exceeding the sum of having the diseases separately). Excess comorbidity costs for patients with 2 diseases were higher for younger-aged versus for older-aged patients; e.g. excess expenditure for 45–49-year-old males with CVD and chronic lung, liver, or kidney disease was 10 times higher than for 75–79-year-old males and 6 times higher for females. The remaining three-quarters of health expenditure was broken down as follows across the 6 NCDs (as though they were the only disease to affect a person): heart disease and stroke, 18.7%; musculoskeletal, 16.2%; neurological, 14.4%; cancer, 14.1%; chronic lung, liver, or kidney disease, 7.4%; and diabetes, 5.5%.
