Persistent increase in hospitalisation for atrial fibrillation in USA between 2000 and 2010

Patel NJ, Deshmukh A, Pant S, et al.,
Circulation. 2014 May 19

Background

The prevalence of atrial fibrillation (AF) is projected to increase to 15.9 million worldwide by the year 2050 [1,2].  More than half of these patients will be aged 80 years or older, thus the socioeconomic implications are enormous. The economic burden associated with AF is growing considerably, mainly due to the rising cost of hospitalisations [3].
Understanding trends in AF-related hospitalisation is important for appropriate health care planning and to be able to reduce the demands on the health care system. Furthermore, a national study may also identify specific patters across subpopulations and geographic regions, which may help to identify vulnerable groups for targeted health care interventions.
This study therefore performed a contemporary evaluation of the burden of AF-related hospitalisation, to determine temporal trends and to assess the effect of comorbid diagnoses and demographics on in-hospital mortality, length of stay and total cost of care during the hospitalisation. To this extent, the Nationwide Inpatient Sample (NIS) inpatient database was used, which contains all discharge data from over 1200 American hospitals. 3960011 hospitalisations for AF in the period from 2000 to 2010 were analysed.

Main results

• AF hospitalisation rate increased from 1522 to 1812 per million US inhabitants per year in the period from 2000 to 2010 (relative increase: 14.4%, P<0.001). A rise was seen in all age groups, albeit to different extends, except for those aged 18-34 years old (-3.1%, P=0.686).
• AF hospitalisation rate was higher in females and white race throughout the study period. Relative rates of increment were, however, higher in males (16.9% vs. 12.1% in females, P<0.001), and in non-whites vs. whites (35.1% vs. 25.3%, P<0.001).
• Mean age of hospitalised female patients was 74, and of male patients 66 years. Above 65 years, there were more females than males (61% vs. 39%), while in those younger than 65 years, the ratio was the other way around (34% vs. 66%).
• Overall AF-related inpatient mortality decreased from 1.2% in 2000 to 0.9% in 2010. Mortality was highest in those 80 years and older (1.9%). Also patients with heart failure (8.2%) and chronic renal failure (2.6%) showed significantly higher mortality, as compared to patients without these comorbidities.
• Median length of stay (LOS) was 3 days (IQR: 2-5), which was stable over the study period.
• After inflation correction, the mean cost of AF hospitalisation increased with 24.0% (P<0.001) between 2001 and 2010.

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Conclusion

These data show that in the United States, over a period of 11 years, AF hospitalisations increased significantly. Most admissions occurred in patients over 65 years old, and patients of 80 years and older exhibited the largest increase in admissions and greater in-hospital mortality than other age groups. Mortality associated with AF decreased over time, except in patients with heart failure. Length of stay was stable over time, but cost of care increased during the study period.
In light of the persistent increase in AF hospitalisation and associated costs, prevention of AF hospitalisation and effective outpatient management should be employed to reduce burden on the health care system.

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Referenties

1. Go AS, Hylek EM, Phillips KA, et al. Prevalence of diagnosed atrial fibrillation in adults: National implications for rhythm management and stroke prevention: The anticoagulation and risk factors in atrial fibrillation (atria) study. JAMA. 2001;285:2370-2375.
2. Miyasaka Y, Barnes ME, Gersh BJ, et al. Secular trends in incidence of atrial fibrillation in olmsted county, minnesota, 1980 to 2000, and implications on the projections for future prevalence. Circulation. 2006;114:119-125.
3. Coyne KS, Paramore C, Grandy S, et al. Assessing the direct costs of treating nonvalvular atrial fibrillation in the united states. Value health. 2006;9:348-356.