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Standardized Infection Surveillance in Long-Term Care Interfacility Comparisons From a Regional Cohort of Facilities

  • Kurt B. Stevenson (a1), James Moore (a2), Holly Colwell (a2) and Barbara Sleeper (a2)



To measure infection rates in a regional cohort of long-term-care facilities (LTCFs) using standard surveillance methods and to analyze different methods for interfacility comparisons.


Seventeen LTCFs in Idaho.


Prospective, active surveillance for LTCF-acquired infections using standard definitions and case-finding methods was conducted from July 2001 to June 2002. All surveillance data were combined and individual facility performance was compared with the aggregate employing a variety of statistical and graphic methods.


The surveillance data set consisted of 472,019 resident-days of care with 1,717 total infections for a pooled mean rate of 3.64 infections per 1,000 resident-days. Specific infections included respiratory (828; rate, 1.75), skin and soft tissue (520; rate, 1.10), urinary tract (282; rate, 0.60), gastrointestinal (77; rate, 0.16), unexplained febrile illnesses (6; rate, 0.01), and bloodstream (4; rate, 0.01). Initially, methods adopted from the National Nosocomial Infections Surveillance System were used comparing individual rates with pooled means and percentiles of distribution. A more sensitive method appeared to be detecting statistically significant deviations (based on chi-square analysis) of the individual facility rates from the aggregate of all other facilities. One promising method employed statistical process control charts (U charts) adjusted to compare individual rates with aggregate monthly rates, providing simultaneous visual and statistical comparisons. Small multiples graphs were useful in providing images valid for rapid concurrent comparison of all facilities.


Interfacility comparisons have been demonstrated to be valuable for hospital infection control programs, but have not been studied extensively in LTCFs.


Corresponding author

Qualis Health, 720Park Boulevard, Suite 120, Boise, ID


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1.Smith, PW, Rusnak, PG. Infection prevention and control in the long-term-care facility. Infect Control Hosp Epidemiol 1997;18:831849.
2.Haley, RW, Culver, DH, White, JW. The efficacy of infection surveillance and control programs in preventing nosocomial infections in U.S. hospitals. Am J Epidemiol 1985;121:182205.
3. Centers for Disease Control and Prevention. Public health focus: surveillance, prevention, and control of nosocomial infections. MMWR 1992;41:783787.
4.Roy, MC, Perl, TM. Basics of surgical-site infection surveillance. Infect Control Hosp Epidemiol 1997;18:659668.
5.Misset, B, Timsit, JF, Dumay, MF, et al.A continuous quality-improvement program reduces nosocomial infection rates in the ICU. Intensive Care Med 2004;30:395400.
6.Smith, PW. Development of nursing home infection control. Infect Control Hosp Epidemiol 1999;20:303305.
7.Goldrick, BA. Infection control programs in skilled nursing long-term care facilities: an assessment, 1995. Am J Infect Control 1999;27:49.
8.Strausbaugh, L, Joseph, CL. Epidemiology and prevention of infections in residents of long term care facilities. In: Mayhall, CG, ed. Hospital Epidemiology and Infection Control. Philadelphia: Lippincott Williams & Wilkins; 1999:14611482.
9.Strausbaugh, LJ. Infection control in long-term care: news from the front. Am J Infect Control 1999;27:13.
10.Loeb, M. Antibiotic use in long-term-care facilities: many unanswered questions. Infect Control Hosp Epidemiol 2000;21:680683.
11.Goldrick, BA. Infection control programs in long-term-care facilities: structure and process. Infect Control Hosp Epidemiol 1999;20:764769.
12.Archibald, LK, Gaynes, RP. Hospital-acquired infections in the United States: the importance of interhospital comparisons. Infect Dis Clin North Am 1997;11:245255.
13.Stevenson, KB. Regional data set of infection rates for long-term care facilities: description of a valuable benchmarking tool. Am J Infect Control 1999;27:2026.
14.White, C, Pizer, SD, White, AJ. Assessing the RUG-III resident classification system for skilled nursing facilities. Health Care Financing Review 2002;24:715.
15.Kane, RL. Improving the quality of long-term care. JAMA 1995;273: 13761380.
16.McGeer, A, Campbell, B, Emori, TG, et al.Definitions of infection for surveillance in long-term care facilities. Am J Infect Control 1991;19:17.
17.Greenland, S, Rothman, KJ. Introduction to categorical statistics. In: Rothman, KJ, Greenland, S, eds. Modern Epidemiology. Philadelphia: Lippincott Williams & Wilkins; 1998.
18.Duncan, AJ. Quality Control and Industrial Statistics. Columbus, OH: McGraw-Hill; 1986.
19.Tufte, ER. The Visual Display of Quantitative Information. Cheshire, CT: Graphics Press; 1983.
20.Centers for Disease Control and Prevention. National Nosocomial Infections Surveillance (NNIS) System report: data summary from January 1992 through June 2003, issued August 2003. Am J Infect Control 2003;31:481498.
21.Gaynes, RP, Culver, DH, Emori, TG, et al.The National Nosocomial Infections Surveillance System: plans for the 1990s and beyond. Am J Med 1991;91(suppl 3B):116S120S.
22.Centers for Medicare & Medicaid Services. Nursing Home Compare. Baltimore, MD: Centers for Medicare & Medicaid Services. Available at
23.Emori, TG, Edwards, JR, Culver, DH, 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.
24.Morton, AP, Whitby, M, McLaws, ML, et al.The application of statistical process control charts to the detection and monitoring of hospital-acquired infections. Journal of Quality in Clinical Practice 2001;21:112117.
25.Sellick, JA Jr.The use of statistical process control charts in hospital epidemiology. Infect Control Hosp Epidemiol 1993;14:649656.
26.Benneyan, JC. Statistical quality control methods in infection control and hospital epidemiology: Part II. Chart use, statistical properties, and research issues. Infect Control Hosp Epidemiol 1998;19:265283.


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