• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of amjphAmerican Journal of Public Health Web SiteAmerican Public Health Association Web SiteSubmissionsSubscriptionsAbout Us
Am J Public Health. 1997 December; 87(12): 1944–1950.
PMCID: PMC1381234

The impact of influenza epidemics on mortality: introducing a severity index.

Abstract

OBJECTIVES: The purpose of this study was to assess the impact of recent influenza epidemics on mortality in the United States and to develop an index for comparing the severity of individual epidemics. METHODS: A cyclical regression model was applied to weekly national vital statistics from 1972 through 1992 to estimate excesses in pneumonia and influenza mortality and all-cause mortality for each influenza season. Each season was categorized on the basis of increments of 2000 pneumonia and influenza excess deaths, and each of these severity categories was correlated with a range of all-cause excess mortality. RESULTS: Each of the 20 influenza seasons studied was associated with an average of 5600 pneumonia and influenza excess deaths (range, 0-11,800) and 21,300 all-cause excess deaths (range, 0-47,200). Most influenza A(H3N2) seasons fell into severity categories 4 to 6 (23,000-45,000 all-cause excess deaths), whereas most A(H1N1) and B seasons were ranked in categories 1 to 3 (0-23,000 such deaths). CONCLUSIONS: From 1972 through 1992, influenza epidemics accounted for a total of 426,000 deaths in the United States, many times more than those associated with recent pandemics. The influenza epidemic severity index was useful for categorizing severity and provided improved seasonal estimates of the total number of influenza-related deaths.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.5M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Housworth J, Langmuir AD. Excess mortality from epidemic influenza, 1957-1966. Am J Epidemiol. 1974 Jul;100(1):40–48. [PubMed]
  • Public Health Weekly Reports for NOVEMBER 11, 1932. Public Health Rep. 1932 Nov 11;47(46):2159–2189. [PMC free article] [PubMed]
  • COLLINS SD, LEHMANN J. Trends and epidemics of influenza and pneumonia: 1918-1951. Public Health Rep. 1951 Nov 16;66(46):1487–1516. [PMC free article] [PubMed]
  • EICKHOFF TC, SHERMAN IL, SERFLING RE. Observations on excess mortality associated with epidemic influenza. JAMA. 1961 Jun 3;176:776–782. [PubMed]
  • Stroup DF, Thacker SB, Herndon JL. Application of multiple time series analysis to the estimation of pneumonia and influenza mortality by age 1962-1983. Stat Med. 1988 Oct;7(10):1045–1059. [PubMed]
  • Serfling Robert E. Methods for current statistical analysis of excess pneumonia-influenza deaths. Public Health Rep. 1963 Jun;78(6):494–506. [PMC free article] [PubMed]
  • Alling DW, Blackwelder WC, Stuart-Harris CH. A study of excess mortality during influenza epidemics in the United States, 1968-1976. Am J Epidemiol. 1981 Jan;113(1):30–43. [PubMed]
  • Choi K, Thacker SB. An evaluation of influenza mortality surveillance, 1962-1979. I. Time series forecasts of expected pneumonia and influenza deaths. Am J Epidemiol. 1981 Mar;113(3):215–226. [PubMed]
  • Choi K, Thacker SB. Mortality during influenza epidemics in the United States, 1967-1978. Am J Public Health. 1982 Nov;72(11):1280–1283. [PMC free article] [PubMed]
  • Lui KJ, Kendal AP. Impact of influenza epidemics on mortality in the United States from October 1972 to May 1985. Am J Public Health. 1987 Jun;77(6):712–716. [PMC free article] [PubMed]
  • Glezen WP, Payne AA, Snyder DN, Downs TD. Mortality and influenza. J Infect Dis. 1982 Sep;146(3):313–321. [PubMed]
  • Barker WH, Mullooly JP. Underestimation of the role of pneumonia and influenza in causing excess mortality. Am J Public Health. 1981 Jun;71(6):643–645. [PMC free article] [PubMed]
  • Simonsen L, Clarke MJ, Stroup DF, Williamson GD, Arden NH, Cox NJ. A method for timely assessment of influenza-associated mortality in the United States. Epidemiology. 1997 Jul;8(4):390–395. [PubMed]

Articles from American Journal of Public Health are provided here courtesy of American Public Health Association

Formats: