THE AGE‐ AND SEX‐SPECIFIC INCIDENCE AND MEDICAL EXPENSES OF HEART FAILURE HOSPITALIZATION IN 2005 IN TAIWAN: A STUDY USING DATA FROM THE NATIONAL HEALTH INSURANCE

Abstract

To the Editor: Heart failure increases sharply with aging.1-6 Vital statistics in Taiwan show that life expectancy has been increasing—from 70.8 in 1985 to 71.9 in 1995 and 74.5 in 2005 for men and from 75.8 in 1985 to 77.8 in 1995 and 80.8 in 2005 for women.7 Although the clinical burden of heart failure is expected to increase in Taiwan, its epidemiology remains unclear. This study analyzed the incidence of and medical expenses for hospitalization for heart failure in Taiwan during 2005 using the reimbursement data of the National Health Insurance (NHI), which is a compulsory and universal health insurance implemented since March 1, 1995.8 The NHI covered 98.0% of the total population, and more than 90% of the medical institutes were contracted to the Bureau of NHI for providing healthcare services (those not contracted provided fewer services) in 2005.9 For each admission, computerized data of medical expenses, dates of admission and discharge, identification number, sex, birth date, and diagnostic codes based on the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) were available. The National Health Research Institute of Taiwan extracted the data of a random sample of 1,000,000 subjects covered by the NHI during 2005 for the purpose of academic research. The sample was representative of the general population of Taiwan.10 A total of 79,299 of the 1,000,000 subjects had records of one or more hospitalizations during 2005. Of them, 2,712 (3.4%) had a diagnosis of heart failure (ICD-9-CM codes 398.91, 402.11, 402.91, 404.11, 404.13, 404.91, 404.93, and 428) as a primary or secondary diagnosis. Patients with a first hospitalization with a diagnosis of heart failure were recruited. The incidence of and total medical expenses for hospitalization for heart failure for 2005 were calculated according to age (each 5-year increment) and sex. The numerators of the incidences were the total number of patients with a diagnosis of heart failure in the specific subgroups of age and sex, and the denominators were the number of insured in the subgroups in the randomly selected 1,000,000 subjects from the NHI data set. The incidence of hospitalization for heart failure and percentage of total medical expenses according to age and sex are shown in Table 1. The total medical expenses for men, women, and all patients were 151,752,015, 123,736,224, and 275,488,239 New Taiwan dollars, respectively (33 New Taiwan dollars equals approximately 1 U.S. dollar). Incidence was highly dependent on age in either sex and was especially high in subjects aged 65 and older. Men had a higher incidence than women in all age groups except those aged 75 and older. The population aged 65 and older represented less than 10% of the total population in either sex but used 81.1% (77.5% in men and 85.6% in women) of the total medical expenses for first hospitalization for heart failure. Consistent with other studies,1-6 these data showed that heart failure was age dependent and that men had a higher incidence than women (Table 1). In the Framingham follow-up study, the incidence of heart failure was 2, 5, and 10 per 1,000 person-years for subjects aged 45 to 54, 55 to 64, and 65 to 74, respectively, in men and 1, 3, and 8 per 1,000 person-years, respectively, in women.2 These were comparable to the data in Table 1. In the United States, more than 80% of hospitalizations for heart failure occurred in people aged 65 and older.6 This was similar to the current study, which showed that 78.4% of all heart failure occurred in such elderly subjects (74.3% in men, 82.8% in women; Table 1). Similarly, these elderly subjects also used 81.1% (77.5% in men, 85.6% in women; Table 1) of the total medical expenses for heart failure hospitalization. In summary, data from a representative population using the NHI in Taiwan shows that the incidence of heart failure hospitalization increased sharply with age, with male predominance. Although people aged 65 and older accounted for less than 10% of the total population, they represented more than 80% of the subjects admitted for heart failure and used approximately 80% of the total medical expenses for hospitalization for heart failure. With the aging of the population, prevention and control of risk factors are important in curbing the increasing burden of heart failure in Taiwan. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the author and has determined that the author has no financial or any other kind of personal conflicts with this paper. Author Contributions: Author is the sole contributor to this letter. Sponsor's Role: None.