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Converting Incidence and Prevalence Data of Nosocomial Infections Results From Eight Hospitals

Published online by Cambridge University Press:  02 January 2015

Petra Gastmeier*
Affiliation:
Institute of Hygiene, Free University Berlin, University Freiburg, Germany
Helga Bräuer
Affiliation:
Institute of Hygiene, Free University Berlin, University Freiburg, Germany
Dorit Sohr
Affiliation:
Institute of Hygiene, Free University Berlin, University Freiburg, Germany
Christine Geffers
Affiliation:
Institute of Hygiene, Free University Berlin, University Freiburg, Germany
Dietmar H. Forster
Affiliation:
Institute for Environmental Medicine and Hospital Epidemiology, University Freiburg, Germany
Franz Daschner
Affiliation:
Institute for Environmental Medicine and Hospital Epidemiology, University Freiburg, Germany
Henning Rüden
Affiliation:
Institute of Hygiene, Free University Berlin, University Freiburg, Germany
*
Institute of Hygiene, Free University, Berlin, Heubnerweg 6, 14059 Berlin, Germany

Abstract

Objective:

To investigate the use of the formula of Rhame and Sudderth for the interconversion of prevalence and incidence data on the frequency of nosocomial infections.

Design:

Comparison of observed and calculated incidence data and prevalence data.

Setting:

One 8-week incidence investigation in the surgical and intensive care units of eight medium-sized hospitals; three separate point-prevalence studies in the same units.

Results:

The overall prevalence observed after the three prevalence studies in 2,169 patients was 6.8% (95% confidence interval [CI95], 5.7-8.0). In 2,882 discharged patients observed during the incidence study, the mean hospitalization was 9.8 days; patients with one or more nosocomial infection had a mean hospitalization time of 22.3 days and a mean interval of 8.2 days from admission to the first day of infection. Based on these data, the overall calculated incidence was 4.7%, whereas the observed incidence was 4.3% (CI95, 3.6-5.2). Vice versa, an overall prevalence of 6.2% was found when calculated from the observed incidence data.

The incidence data calculated from prevalence data also were within the confidence interval of the incidences observed for urinary tract infections and surgical-site infections. (However, it was not possible to convert the data for two of the eight hospitals.)
Conclusion:

The approximate mathematical relationship between the prevalence and incidence data of nosocomial infection is confirmed by this study. However, although it is theoretically possible, we would not recommend the conversion of prevalence into incidence data or vice versa.

Type
Original Articles
Copyright
Copyright © The Society for Healthcare Epidemiology of America 2001

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References

1.Freeman, J, Hutchison, G. Prevalence, incidence and duration. Am J Epidemiol 1980;112:707723.CrossRefGoogle ScholarPubMed
2.Freeman, J, McGowan, JJ. Day-specific incidence of nosocomial infection estimated from a prevalence survey. Am J Epidemiol 1981;114:888901.CrossRefGoogle ScholarPubMed
3.Rhame, F, Sudderth, W. Incidence and prevalence as used in the analysis of the occurrence of nosocomial infection rates. Am J Epidemiol 1981;113:111.CrossRefGoogle Scholar
4.French, G. Repeated prevalence surveys. In: Emmerson, A, Ayliffe, G, eds. Clinical Infectious Diseases. London, UK: Baillière; 1996:179195.Google Scholar
5.Garner, JS, Emori, WR, Horan, TC, Hughes, JM. CDC definitions for nosocomial infections. Am J Infect Control 1988;16:128140.CrossRefGoogle ScholarPubMed
6.Horan, TC, Gaynes, RP, Martone, WJ, Jarvis, WR, Emori, TG. CDC definitions of surgical site infections: a modification of CDC definitions of surgical wound infections. Infect Control Hosp Epidemiol 1992;13:606608.CrossRefGoogle ScholarPubMed
7.Gastmeier, P, Geffers, C, Daschner, F, Rüden, H. Diagnostic training in the surveillance of nosocomial infections: what is feasible and useful? Zent.bl.Hyg.Umweltmed. 1998;201:153166.Google Scholar
8.Gastmeier, P, Kampf, G, Wischnewski, N, Schumacher, M, Daschner, F, Rüden, H. Importance of the surveillance method—various national prevalence studies on nosocomial infections and limits of comparison. Infect Control Hosp Epidemiol 1998;19:661667.CrossRefGoogle Scholar
9.Vincent, J-L, Bihari, D, Suter, PM, Bruning, HA, White, J, Nicolas-Chanoin, MH, et al. The prevalence of nosocomial infections in intensive care units in Europe. JAMA 1995;274:639644.CrossRefGoogle ScholarPubMed
10.Mayon-White, R, Ducel, G, Kereselidze, T, Tikomirov, E. An international survey of the prevalence of hospital-acquired infection. J Hosp Infect 1983;11(suppl A):4348.CrossRefGoogle Scholar
11.French, GL, Wong, SL, Cheng, AFB, Donnan, S. Repeated prevalence surveys for monitoring effectiveness of hospital infection control. Lancet 1989;28:10211023.CrossRefGoogle Scholar
12.French, GL, Cheng, AF. Measurement of the costs of hospital infection by prevalence surveys. J Hosp Infect 1991;18:6572.CrossRefGoogle ScholarPubMed
13.National Nosocomial Infections Surveillance System. National Nosocomial Infections Surveillance (NNIS) Report, Data Summary from October 1986-April 1997, issued May 1997. Am J Infect Control 1997;25:477487.CrossRefGoogle Scholar
14.Delgado-Rodríguez, M, Cueto Espinar, A, Rodríguez-Contreras Pelayo, R, Galvez Vargas, R. A practical application of Rhame and Sudderth's formula on nosocomial infection surveillance. Rev.Epidém.et Santé Publ. 1987;35:482487.Google ScholarPubMed
15.Emori, TG, Edwards, JR, Culver, DH, Sartor, C, Stroud, LM, Gaunt, E, et al. Accuracy of reporting nosocomial infections in intensive-care–unit patients to the National Nosocomial Infections Surveillance System: a pilot study. Infect Control Hosp Epidemiol 1998;19:308316.CrossRefGoogle Scholar
16.Gastmeier, P, Kampf, G, Hauer, T, Schlingmann, J, Schumacher, M, Daschner, F, et al. Experience with two validation methods in a prevalence survey on nosocomial infections. Infect Control Hosp Epidemiol 1998;19:668673.CrossRefGoogle Scholar