Temporal trends (2002-2014) of incidence and shockable status of adult emergency medical service attended out-of-hospital cardiac arrest of presumed cardiac aetiology in Queensland.

Abstract

To describe trends in incidence and shockable status of adult out-of-hospital cardiac arrest (OHCA) of presumed cardiac aetiology attended by Queensland Ambulance Service (QAS) paramedics between 2002 and 2014. The QAS cardiac arrest registry was used to collect data. Analyses included age-standardised rates by gender for all adults and older adults only (65 years+); age-specific incidence rates of young adults (18-49), middle age adults (50-64) and five groups of older adults (65-69, 70-74, 75-79, 80-84 and 85+); and proportions of shockable versus non-shockable initial rhythm together and by age group (young, middle age and older adults). Temporal trends were analysed. Over the 13 years, 32 346 cases of adult OHCA of presumed cardiac aetiology were recorded on the QAS OHCA registry. Age-standardised incidence reduced significantly over time overall and in males only, in all adults and independently in older adults. A significant reduction independently in females was observed only in older adults. Age-specific rates reduced in the 18-49, 70-74, 75-79 and 80-84 year age groups, increased in the 50-64 age group (largely attributable to females) and no significant trends were found in the 65-69 and 85+ age groups. The proportion of cases with an initially shockable rhythm significantly decreased overall. This trend was observed independently in older adults, but not in young or middle age adults. Age-standardised incidence has reduced with a period of stagnation in the middle age and early older years. These factors require consideration in data interpretation and strategy planning.