Prevalence and characteristics of nursing home-acquired infections in the aged.

OBJECTIVES

This study provides estimates of the prevalence of infections in all patients from a representative sample of 53 Maryland nursing homes; identifies risk factors for these infections; and describes diagnostic procedures carried out.

METHODS

The records of 4,259 patients in a stratified random sample of 53 Maryland nursing homes were reviewed for diagnostic procedures, medical, functional, and behavioral status. Infections were identified by signs, symptoms, and laboratory findings.

RESULTS

Study patients were characteristic of aged patients in US nursing homes. The prevalence of infections actually acquired in the nursing home (80% of all infections) was 4.4%. Multivariate analysis revealed that skin infections (35% of nursing home-acquired infections) were associated with skin ulcers and inversely with urine incontinence. Fevers of uncertain source (13%) were associated with bladder catheters. Symptomatic urinary infections (12%) and lower respiratory infections (12%) were associated with bedfast status, and the latter with tracheostomy and lung disease. Skin ulcers, urethral catheters, and bedfast status were markers for nursing home-acquired infection. The prevalence of infection in patients with all three markers was 32%; in patients with none, 2%. Fewer than a quarter of the four most common nursing home-acquired infections received an evaluation which met minimal diagnostic criteria established by a panel of infectious disease specialists and geriatricians. Patients with dementia, those in large homes (greater than 150 beds), and those in urban homes were less likely to be evaluated in a manner meeting these criteria.

CONCLUSIONS

Use of three characteristics (ie skin ulcers, urethral catheters, bedfast status) to identify patients at risk for nursing home-acquired infections may allow targeted infection surveillance and prevention programs. In addition, nursing home-acquired infections are not evaluated uniformly across patients and facilities, suggesting the need to establish, through further study, guidelines for such evaluations.