Influenza and Pneumonia Mortality Trends 2000-2007 DS 10-10000
California Total Population
The age-adjusted death rate of influenza and pneumonia significantly declined from 2000 to 2007. In 2007, the age-adjusted death rate for influenza and pneumonia per 100,000 California residents was 18.8, which represented a decrease of 35.6 percent from a rate of 29.2 in 2000. The chart below displays California age-adjusted death rates from 2000 through 2007 and a trend line. For additional information about trend analysis, see Technical Notes.
The minor annual variability of influenza and pneumonia death rates between 2004 and 2005 was due to the peak dates of occurrence for the influenza season, which do not necessarily align with the calendar year.6 Refer to Table 3 (PDF)for detailed influenza and pneumonia age adjusted rates.
Age-Specific Death Rate
Except for those under 1, the risk of dying from influenza and pneumonia increases with age. The minimum and maximum age-specific death rates for age groups that had reliable rates during each year of study were as follows:
• Under 1 year (4.6 to 7.1)
• 25-34 years (0.4 to 0.8)
• 35-44 years (1.1 to 1.9)
• 45-54 years (3.0 to 4.6)
• 55-64 years (8.4 to 12.0)
• 65-74 years (32.6 to 47.4)
• 75-84 years (134.8 to 204.0)
• 85 and older (582.3 to 947.9)
The age-specific death rate for persons in each age group showed slight year-to-year variations from 2000 through 2007. Annual age-specific influenza and pneumonia death rates for the California population are displayed in Table 2a (PDF). For additional information about age-specific death rates and age groups, please see the Technical Notes.
Crude Death Rates
During this period, the actual risk of dying per 100,000 population, or crude rate, ranged from 17.2 to 24.5. (Table 2a (PDF)).
Crude death rates show the actual rate of dying in a given population, but because populations will vary in age distribution, crude rates do not provide a statistically valid method for comparing sex or race/ethnic groups, geographic areas, or multiple reporting periods.7 Please see age specific or age-adjusted death rates for comparisons.
Number of Deaths
From 2000 to 2007, California recorded 1,872,245 resident deaths, of which 61,523 deaths (3.3 percent) were attributed to influenza and pneumonia. In 2007, California recorded 233,467 deaths of which 6,522 deaths (2.8 percent) were due to influenza and pneumonia. The number of deaths by influenza and pneumonia of California residents decreased from 8,355 in 2000 to 6,522 in 2007.
The number of deaths decreased every year relative to 2000, although slight increases occurred between 2002 and 2003 (86 deaths) and between 2004 and 2005 (206 deaths). The increase in the number deaths between these years is primarily due to the occurrence of the influenza season peak dates. Both nationally and in California, the 2003-2004 influenza season peaked at the end of 2003 whereas the 2004-2005 influenza season peaked in the beginning of 2005, resulting in a decrease of deaths during the calendar year of 2004. 6 The chart below illustrates the fluctuation in seasons 2002-2003 through 2005 2006 by week of deaths beginning with week 40 and ending at week 20, the end of the influenza season.
Traditionally, influenza circulates during winter months, but durations and timing can vary. On the national level, CDC conducts surveillance during the influenza season, which usually begins October (week 40) and continues to mid-May (week 20).8 In addition, the Immunization Branch within the California Department of Public Health conducts influenza surveillance in California within the same time span, using inpatient, pharmacy, sentinel physician, and laboratory data. 9
Number of Deaths by Sex
During 2000-2007, the number of females dying from influenza and pneumonia was 33,410 (54.3 percent), outnumbering male deaths at 28,113 (45.7 percent). In 2007, females accounted for 54.0 percent (N=3,523) of deaths whereas males accounted for 46.0 percent (N=2,999). This was consistent throughout the period.
Number of Deaths by Race/Ethnicity
Of the 61,523 influenza and pneumonia deaths from 2000 through 2007, Whites accounted for 73.0 percent followed by Hispanics (12.0 percent), Asians (8.3 percent), Blacks (6.1 percent), American Indian (0.3 percent), Two or More Races (0.2 percent), and Pacific Islander (0.2 percent). A similar pattern is seen in the 2007 race/ethnicity composition, which is the last year examined. In 2007, out of the 6,522 deaths, there were 4,439 White deaths (68.1 percent) followed by 891 Hispanic deaths (13.7 percent), 690 Asian deaths (10.6 percent), 448 Black deaths (6.9 percent), 14 American Indian deaths (0.2 percent), 23 Two or More Races deaths (0.4 percent), and 17 Pacific Islander deaths (0.3 percent). Percentages may not add to 100 percent due to rounding.
For additional information regarding the number of events, please see Technical Notes.
Age Distribution of Influenza and Pneumonia Deaths
The average age of a California resident who died of influenza and pneumonia between 2000 and 2007 was 81.4 years with a standard deviation of 14.1 years. Almost 50 percent of influenza and pneumonia deaths occurred to people aged 85 and older, and when people aged 65 to 84 were included it rose to approximately 90 percent.
The chart below shows the age distributions of influence and pneumonia deaths.