Understanding changing patterns of survival and hospitalization for heart failure over two decades in New Zealand: utility of 'days alive and out of hospital' from epidemiological data

To describe changes in heart failure (HF) epidemiology in New Zealand between 1988 and 2008 using the number of days alive and out of hospital after a first hospitalization for HF, and to use these data to evaluate the overall impact of changing patterns of hospitalization and survival. We performed a population analysis of all HF hospitalization and mortality data from 1 January 1988 to 31 December 2008 in New Zealand. The main outcome measures were: days alive and out of hospital, age standardized hospitalization rates, and mortality after an index hospitalization for HF. The number of days alive and out of hospital at 2 years increased by 2 months over the two decades of the study (from 448.8 to 511.3 days). Age standardized index HF hospitalization rates increased from 1988 to 1999, and declined thereafter, current rates are 106.9/100 000 for women and 174.3/100 000 for men. Patient age at index admission progressively increased, and hospital length of stay decreased. Mortality rates progressively decreased until 2000, but there has been no further decrease since then. Total hospital days have decreased up to 2008. There have been major changes in the epidemiology of HF in New Zealand between 1988 and 2008, during which time there have been important changes in HF management. Despite increasing age, hospitalization rates are now declining and patients with HF are surviving longer out of hospital and with fewer hospital days. These results support the need for continued emphasis on delivery of effective community-based care for patients with this long-term condition.