Antibiotic use, hospital admissions, and mortality before and after implementing guidelines for nursing home-acquired pneumonia.

OBJECTIVES: To compare two strategies for implementing guidelines for nursing home-acquired pneumonia (NHAP) and to measure outcomes associated with treatment in accordance with the guidelines. DESIGN: Randomized controlled trial. SETTING: Ten skilled nursing facilities (SNFs) from a single metropolitan area. PARTICIPANTS: Patients with an episode of pneumonia acquired more than 3 days after admission to SNF (N = 350): 226 preintervention episodes of pneumonia and 116 postintervention episodes. INTERVENTIONS: Multi-faceted education intervention including small-group consensus process limited to physicians and a similar intervention that included physicians and nurses within randomly selected SNFs. MEASUREMENTS: Antibiotic use at diagnosis compared with the guidelines, hospital admission, severity of pneumonia, and 30-day mortality. RESULTS: Data were complete for 344 episodes of NHAP. For the preintervention group (n = 226), 62.2% (79/127) of the episodes were treated with parenteral antibiotics (PA) when PA were recommended by the guidelines and 57.6% (57/99) of episodes were treated with oral antibiotics (OA) when OA were indicated by the guidelines. Postintervention, treatment with PA and OA according to the guidelines was not significantly different between the two groups of randomized SNFs. A multivariate analysis comparing PA use pre- and postintervention for all SNFs, adjusted for variation in the frequency and severity of pneumonia, found significantly more of the postintervention episodes were treated with PA in accordance with the guidelines (P < .02). A preintervention significant difference in 30-day mortality observed between episodes with indications for PA (37.8% (48/127)) and episodes with indications for OA (6.1% (6/99)) (P < .001) was not present postintervention (11.5% (6/52); (23.8% (15/64); P = .06). There was no significant difference in 30-day mortality preintervention and postintervention for episodes with guideline indications for OA (P = .35) or for PA (P = .05) (P = .16 for multivariate analysis). The difference in PA use was not associated with significant differences in hospital admissions for episodes on NHAP. CONCLUSION: The increase in the use of PA provides evidence that care within SNFs can be significantly changed using standard quality improvement techniques. Use of the guidelines did not significantly affect mortality. The addition of a practical severity of NHAP model or a change in reimbursement structure may enhance the guidelines' impact on hospitalization for NHAP. The financial benefits available with use of the guidelines will be limited unless the guidelines contribute to a reduction in rates of hospitalization.

Antibiotic-resistant organisms among long-term care facility residents on admission to an inpatient geriatrics unit: Retrospective and prospective surveillance.

BACKGROUND: There is limited information about antibiotic-resistant organisms in community long-term care facilities (LTCFs). The objective of this study was to obtain data on resistant organisms in residents from community LTCFs admitted to an inpatient acute geriatrics service (AGS). METHODS: Two studies were performed. In the first study, bacteriology records of all admissions to the AGS for the period from November 1, 1998, through June 30, 2000, were reviewed for resistant organisms (methicillin-resistant Staphylococcus aureus [MRSA], vancomycin-resistant enterococci [VRE], and resistant gram-negative bacilli). In the second study, residents admitted to the AGS during a 2-month period (N = 92 admissions) had surveillance cultures (nares, gastrostomy site, wounds, and urine) for resistant organisms done within 72 hours of admission. RESULTS: In the retrospective study, there were 727 admissions, of which 437 (60%) had 928 cultures within 72 hours of admission; 590 (64%) cultures grew 1 or more pathogens. Urine (65%) and blood (26%) cultures accounted for 91% of all cultures done. Rates of resistance by culture site were as follows: urine (resistant organism in 16.6% of 373 cultures), blood (6.7% of 60 cultures), wound (52% of 23 cultures), and sputum (40% of 20 cultures). MRSA and enterococci with high-level gentamicin resistance were the most common resistant organisms identified. No VRE were isolated; only 3% of 421 gram-negative isolates were considered resistant strains compared with 19% (P <.001) of gram-positive isolates. In the prospective study, 17% of 92 residents were found to have a resistant organism in 1 or more surveillance cultures; the most common resistant organisms were MRSA and high-level gentamicin-resistant enterococci. Only 1 resident was found to have VRE in a rectal swab culture; resistant gram-negative bacilli also were uncommon. CONCLUSIONS: Among residents of community LTCFs admitted to an AGS, resistant organisms were identified infrequently (<20% of admissions). MRSA was the most common resistant organism; VRE and resistant gram-negative bacilli were rare. These findings vary from other studies suggesting that there may be geographic variation in the epidemiology of resistant organisms among residents of community LTCFs.

Impact of nosocomial infection on length of stay and functional improvement among patients admitted to an acute rehabilitation unit.

OBJECTIVE: To identify factors predictive of length of stay (LOS) and the level of functional improvement achieved among patients admitted to an acute rehabilitation unit for the first time, with special reference to the role of nosocomial infection. SETTING: A 40-bed acute rehabilitation unit within a 300-bed, tertiary-care, public, university-affiliated hospital. STUDY POPULATION: All patients admitted to the unit between January 1997 and July 1998. DESIGN: Prospective cohort study in which demographic and clinical data, including occurrence of nosocomial infection, were collected during the entire unit admission of each patient. Multivariate linear regression analysis was used to identify factors predictive of unit LOS or improvement in functional status as measured by the change in the Functional Independence Measure (FIM) score between admission and discharge (deltaFIM). RESULTS: There were 423 admissions to the rehabilitation unit during the study period, of which 91 (21.5%) had spinal cord injury (SCI) as a principal diagnosis. One hundred seven nosocomial infections occurred during 84 (19.9%) of the 423 admissions. The most common infections were urinary tract (31.8% of all infections), surgical-site (18.5%), and Clostridium difficile diarrhea (15%). Only one patient died of infection. After controlling for severity of illness on admission, functional status on admission, age, and other clinical factors, the significant positive predictors of unit LOS were as follows: SCI (P<.001), pressure ulcer (.002), and nosocomial infection (<.001). Significant negative predictors of deltaFIM were age (P<.001), FIM score on admission (<.001), prior hospital LOS (.002), and nosocomial infection (.007). CONCLUSIONS: Several variables were identified as contributing to a longer LOS or to a smaller improvement in functional status among patients admitted for the first time to an acute rehabilitation unit. Of these variables, only nosocomial infection has the potential for modification. Studies of new approaches to prevent infections among patients undergoing acute rehabilitation should be pursued.

Community-acquired bacteremia at a teaching versus a nonteaching hospital: impact of acute severity of illness on 30-day mortality.

BACKGROUND: Few studies have focused recently on the epidemiology of community-acquired bacteremia (CAB) and there have been few comparisons of CAB in teaching versus nonteaching hospitals. OBJECTIVES: To compare the clinical characteristics, acute severity of illness, and 30-day mortality of patients with CAB admitted to a teaching and a nonteaching hospital and to define predictors of 30-day mortality among patients with CAB that would be identifiable at the time of admission to the hospital. METHODS: This was a retrospective study of CAB at a teaching hospital (n = 174 episodes) compared to a community nonteaching hospital (n = 74 episodes) during 1995. Data collected included demographic characteristics, underlying diseases, sources of CAB, and antimicrobial therapy. Acute severity of illness on admission was measured by using the acute physiology score component of the Acute Physiology and Chronic Health Evaluation III system (APS APACHE III). MAIN OUTCOME MEASURE: Status, dead or alive, 30 days after admission for CAB. RESULTS: At the nonteaching hospital, patients were older but, on average, significantly less acutely ill (as measured by the admission APS APACHE III score) than were those at the teaching hospital. In contrast, patients with HIV infection, posttransplantation, or on hemodialysis were identified only at the teaching hospital. Overall, organisms causing CAB at both hospitals were similar except that Staphylococcus aureus CAB occurred significantly more often at the teaching hospital and Escherichia coli CAB occurred more often at the nonteaching hospital. There was no significant difference in 30-day mortality in patients with CAB between the teaching hospital (19.3%) and the nonteaching hospital (16.7%; P =.63). APS APACHE III score on admission identified episodes of CAB with a low- and a high-risk for 30-day mortality at both hospitals. Independent predictors of 30-day mortality were APACHE III score on admission (P <.001) and pneumonia as a source of CAB (P =.012). CONCLUSIONS: Among patients with CAB, acute severity of illness on admission was the most important predictor of 30-day mortality at both hospitals. Even though patients with CAB were, on average, more severely ill at the time of admission to the teaching hospital, 30-day mortality rates were not significantly different between the two hospitals because deaths correlated with high APS APACHE III scores at both facilities. The APS APACHE III score on admission provides important prognostic information among patients with CAB.

Antibiotic use and cost indicators at a rural hospital: a pilot project.

BACKGROUND: Recently, simple antibiotic use and cost indicators were developed for use in long-term care facilities. It was hypothesized that these indicators also may be applicable to the acute hospital setting. METHODS: For a 24-month period, data were collected quarterly on antibiotic use and cost indicators for 11 primary care physicians in a 40-bed rural hospital. Indicators included antimicrobial use ratio (AUR, ratio of the number of antibiotic days to the number of patient care days), cost per antibiotic day, and cost of antibiotics per patient care day. One-way analysis of variance and simple linear regression were used to analyze data. RESULTS: Quinolones (oral plus parenteral) accounted for 26% of the total antibiotic days (N = 6020) followed by ceftriaxone (19%) and cefuroxime (11.8%; oral plus parenteral). Overall trends in antibiotic use and cost included a significant increase in quarterly AUR (R(2) = 0.78, P =.004) and cost per patient care day (R(2) = 0. 82, P =.002) but no significant change in quarterly total antibiotic costs or cost per antibiotic day. Among physicians there was a significant difference in mean quarterly AUR (P <.001) and mean quarterly cost per patient care day (P <.001) but no significant difference in mean quarterly cost per antibiotic day. Variation in physician-specific cost per patient care day was best explained by variation in AUR (R(2) = 0.75, P <.001). CONCLUSIONS: Significant variation in simple antibiotic use and cost indicators was identified at a rural hospital from both the facility and physician perspective. Standardized methods for antibiotic use and cost monitoring, like the one described in this article, are required before the relationship between antibiotic use and resistance can be fully understood.

Staphylococcus aureus bacteremia: predictors of 30-day mortality in a large cohort.

We performed a retrospective study of a large cohort of patients who had episodes of Staphylococcus aureus bacteremia (SAB) from January 1995 through February 1999 at 1 medical center to identify predictors of 30-day mortality in SAB. Among 293 patients with episodes of SAB, 68 died (23.2%) within 30 days of onset. There was no significant difference in 30-day mortality associated with treatment with vancomycin, a beta-lactam, or a miscellaneous group of antimicrobial agents (P=.180). By logistic regression, an acute physiology score (a component of the acute physiology and chronic health evaluation [APACHE III]) >60 at onset of SAB was the most important predictor of 30-day mortality (odds ratio [OR], 15.7). Other significant predictors were lung (OR, 5.8) or unknown (OR, 4.1) focus of SAB, age > or =65 years (OR, 2.0), and diabetes mellitus (OR, 2.4). Future investigators of SAB should take into consideration acute severity of illness at onset as well as other factors when evaluating or comparing outcomes.

Outcome of nursing home-acquired pneumonia: derivation and application of a practical model to predict 30 day mortality.

OBJECTIVES: To derive a prediction model of 30 day mortality for nursing home-acquired pneumonia (NHAP) based on factors that can be readily identified by nursing home staff at the time of diagnosis and to apply the model to management issues related to NHAP including clarifying the importance of prepneumonia functional status as a predictor of outcome of NHAP. DESIGN: This was a retrospective chart review of 378 episodes of NHAP treated in the nursing home or hospital during two periods: November 1997 to April 1998 and November 1998 to April 1999. SETTING: Eleven nursing homes in the greater Buffalo, NY region. PARTICIPANTS: Nursing home residents with radiographically proven pneumonia who had at least one of the following signs/symptoms: cough, fever, purulent sputum, respiratory rate > or =25 breaths/minute, localized auscultatory findings, or pleuritic pain. MEASUREMENTS: Status (alive or dead) of each resident at 30 days (30 day mortality) after diagnosis of NHAP was the dependent variable. Factors predicting 30 day mortality were identified by logistic regression analysis. A scoring system was developed based on the results of the logistic model. Each episode of NHAP in the derivation cohort was scored using the model and the cohort was stratified by the model score into six categories or risk for mortality (0-5). The predictability of the model in the derivation cohort was measured using receiver operator characteristics curve analysis. RESULTS: Of 378 episodes of NHAP, 74% were treated initially in the nursing home and 26% were hospitalized initially for treatment. The overall 30 day mortality was 21.4%; however, the mortality rate was significantly higher for those treated initially in the hospital (29.6% vs 16.6%; P = .012). Logistic regression analysis identified four predictors of 30 day mortality: (1) respiratory rate >30 breaths/minute (2 points), (2) pulse > 125 beats/minute (1 point), (3) altered mental status (1 point), and (4) a history of dementia (1 point). Applying the scoring system to each episode in the derivation cohort demonstrated increasing mortality with increasing score. The c statistic for the model in the derivation cohort was .74. Based on the severity of NHAP, model episodes treated initially in the hospital were more acutely ill than those who were treated initially in the nursing home, and episodes treated with a parenteral antibiotic in the nursing home were more acutely ill than those who were treated with an oral agent. Functional status was not a predictor of 30 day mortality although there was a trend of higher mortality in the most dependent group (P = .065). The severity of NHAP model was able to define low and high risk mortality groups within a functional status category. CONCLUSIONS: A severity of NHAP model was derived from a large cohort of episodes in multiple facilities. The model had reasonable discriminatory power in the derivation cohort. The model may aid clinicians in making treatment decisions in the nursing home setting and in making hospitalization decisions. Although prepneumonia functional status provides a reasonable estimate of NHAP severity and prognosis, the severity of NHAP model permitted further refinement of these estimates. The severity of NHAP model requires validation before it can be recommended for general use.

Infection control in subacute care.

Little or no published data are available regarding infections or infection control measures in subacute care units in the United States. Infection-control measures designed for long-term care facilities should, in general, suffice for subacute care units. When developing an infection-control program for a subacute unit, one must be continuously cognizant of the objectives of care rendered by such a unit to ensure that policies and procedures are consistent with those objectives.

Prospective surveillance for antibiotic-resistant organisms in patients with spinal cord injury admitted to an acute rehabilitation unit.

BACKGROUND: The objective of this study was to evaluate the epidemiology of antibiotic-resistant organisms among patients with spinal cord injury admitted to an acute rehabilitation unit for the first time. METHODS: After informed consent, 63 patients with spinal cord injury admitted to an acute rehabilitation unit between January 1997 and July 1998 had surveillance cultures (nares, urine, wounds or ulcers, and perineum) done on admission and every 2 weeks thereafter until discharge or as long as 6 weeks after admission. RESULTS: Of the 4 surveillance sites, perineal cultures most commonly grew one or more potential pathogens; however, antibiotic-resistant organisms were most often isolated from wounds or ulcers and least often in urine cultures. Staphylococcus aureus (methicillin-sensitive plus methicillin-resistant) and enterococci represented 44% of all organisms isolated in surveillance cultures. Methicillin-resistant S aureus was the most common resistant organism isolated. Less than 30% of the gram-negative bacilli isolated were considered antibiotic-resistant strains. Nosocomial infection as a result of any resistant organism was infrequent. After adjusting for various confounding factors in a logistic regression model, only the presence of a pressure ulcer predicted carriage of any resistant organism on admission to the rehabilitation unit. Acquisition of a resistant organism after admission to the unit at one or more surveillance sites occurred in 8 (22%) of 36 patients not colonized on admission. CONCLUSIONS: Methicillin-resistant S aureus was the most common resistant organism colonizing patients with spinal cord injury at the time of admission to an acute rehabilitation unit and throughout their stay. However, acquisition of any resistant organism after admission was uncommon on this unit, which used Standard Precautions in the routine care of patients. These findings have implications for the type of isolation procedures on acute rehabilitation units. The low rate of acquisition and infection with MRSA after admission argues against attempts at eradication as a method of control.

Blood cultures: clinical aspects and controversies.

During the past two decades, there have been important advances in blood culture methodology. These advances have resulted in earlier detection and identification of pathogens causing bloodstream infections. However, there are many facets of the blood culture as a diagnostic test that are not affected by new culture methods or systems that continue to cause problems with interpretation of results. The objective of this review is to focus on those factors influencing the results of blood cultures that have clinical relevance. Such factors include skin preparation, timing, procurement techniques, volume of blood obtained, number of cultures, anaerobic blood cultures, and contamination. In addition, bacteremia prediction models are discussed and suggestions are provided as to how these models could be of greater clinical use. Blood culture methods and systems are not discussed in this review.

Epidemiology of nosocomial infection and resistant organisms in patients admitted for the first time to an acute rehabilitation unit.

The objectives of this study were to define the epidemiology of nosocomial bacterial colonization and infection and to define predictors of nosocomial infection among a cohort (n=423) of admissions to an acute rehabilitation unit. Overall, methicillin-resistant Staphylococcus aureus (MRSA) and enterococci were the most commonly identified colonizing organisms. Escherichia coli and Pseudomonas aeruginosa were the most commonly identified colonizing gram-negative bacilli. During 70 (16.5%) of the 423 hospitalizations in the unit, 94 nosocomial infections occurred. The most common infections were those of the urinary tract (30% of 94 infections) or a surgical site (17%), Clostridium difficile diarrhea (15%), and bloodstream infection (12.8%). Antibiotic-resistant bacteria most commonly caused bloodstream infection (41.7%) and surgical site infection (56.3%). Independent predictors of nosocomial infection at the time of admission were functional status (measured with the functional independence measure), APACHE III score, and spinal cord injury. In conclusion, gram-positive organisms were the predominant strains causing nosocomial colonization and infection. The logistic model, if verified, may be useful in defining patients who should be targeted for measures to prevent nosocomial infection.

Treatment guideline for nursing home-acquired pneumonia based on community practice.

OBJECTIVES: To describe the findings of a retrospective study of the treatment of nursing home-acquired pneumonia (NHAP) in 11 nursing homes in one community and the development of a treatment guideline for NHAP using data from the retrospective study. DESIGN: A retrospective chart review of 239 episodes of NHAP occurring between November 1, 1997, and April 30, 1998, was performed. Data regarding antibiotic treatment of NHAP were used to revise a treatment guideline developed by the authors. Further refinements of the guideline were made based on small group discussions with physicians and nurse practitioners caring for the study population. SETTING: Residents with NHAP were identified among the populations of 11 nursing homes in the metropolitan Buffalo, New York area (Erie county). These 11 nursing homes had a total of 2375 beds, comprising nearly one-third of all nursing home beds in the county. PARTICIPANTS: Nursing home residents with chest X-rays showing infiltrates and signs and symptoms of pneumonia. MEASUREMENTS: Antibiotic treatment (drug used, route of administration, and duration of treatment), location of initial treatment (nursing home or hospital), and status (alive or dead) of each resident were recorded 30 days after diagnosis of NHAP. RESULTS: Of the 239 episodes of NHAP, 171 (72%) were initially treated in nursing homes. Of these 171 patients, 105 (61%) were treated only with an oral regimen, whereas 66 (39%) were treated initially with an intramuscular antibiotic and subsequently with an oral regimen. There was no significant difference in 30-day mortality rates between those initially treated in nursing homes (22%) and those initially treated in hospitals (31%; P = .15) or between those initially treated with an oral regimen in nursing homes (21%) and those initially treated with an intramuscular antibiotic in nursing homes (25%; P = .56). There was no consistency in how physicians made the choice to use intramuscular antibiotics in nursing homes, and a logistic model for predicting this approach could explain very little. The frequency of the prescription of various antibiotic agents in nursing homes and in hospitals was tabulated as well as the duration of treatment; specific attention was paid to the timing of the switch to an oral agent among episodes initially treated with a parenteral agent. These data were used in the guideline to make specific recommendations regarding which agent to prescribe, the duration of parenteral therapy, the timing of the switch to an oral regimen, and the duration of treatment. In the setting of informal small groups, the guideline was discussed with physicians who cared for residents with NHAP in the study nursing homes. Revisions made to the guideline were based on these discussions. CONCLUSIONS: A treatment guideline for NHAP was developed primarily on the basis of the practices of geriatricians in one community. These treatment practices were similar to those reported in the literature in terms of the proportion of patients treated in nursing homes and the antibiotics prescribed. The guideline also provided specific recommendations for timing of the switch to an oral agent after parenteral therapy and for duration of treatment. Studies are in progress to determine if use of this guideline will reduce some of the variation observed in the treatment of NHAP.

"Pulse" nasal mupirocin maintenance regimen in patients undergoing continuous ambulatory peritoneal dialysis.

OBJECTIVE: To determine, among patients undergoing continuous ambulatory peritoneal dialysis (CAPD) who were Staphylococcus aureus nasal carriers, if periodic brief "pulses" of nasal mupirocin calcium ointment 2% after completion of a mupirocin eradication protocol would maintain these patients free of carriage. DESIGN: Noncomparative, nonblinded study with historical controls. SETTING: A county medical center. PATIENTS: Patients in a CAPD program during the period April 1996 to May 1998. METHODS: All patients in the CAPD program had monthly nasal cultures for S. aureus. After informed consent, S. aureus nasal carriers were administered mupirocin to the nares twice a day for 5 days followed by nasal mupirocin twice monthly. Peritonitis and exit-site infection rates were monitored independently by CAPD nursing staff. Patients were monitored monthly for adverse effects of mupirocin and compliance with the maintenance regimen. RESULTS: Twenty-four patients in the CAPD program were enrolled in the study and had a median duration of follow-up of 8.5 months. Fifteen (63%) of the 24 patients remained free of nasal carriage on follow-up cultures. Of the 9 patients with positive nasal cultures during the study, 8 had only one positive culture. There was no significant difference in the mean yearly peritonitis rate or S. aureus peritonitis rate (January 1995-May 1998). However, there was a significant decrease in the mean yearly exit-site infection rates both overall (from 8.8 episodes per 100 patients dialyzed per month in 1995 to 4.0 in 1998; P = .008) and due to S. aureus (from 5.6 in 1995 to 0.9 in 1998; P = .03). Adverse effects of nasal mupirocin were mild overall; 1 patient was removed from the study due to an allergic reaction to mupirocin. CONCLUSIONS: Among CAPD patients who were S. aureus nasal carriers, periodic brief treatment with nasal mupirocin after an initial eradication regimen kept them free of carriage, for the most part, with few adverse effects. The pulse mupirocin regimen offers simplicity and possibly better compliance, as well as minimizing exposure to this agent, thereby possibly reducing the risk of resistance. Further studies are warranted to compare this regimen to other commonly used mupirocin maintenance regimens in dialysis patients.

Using admission characteristics to predict return to the community from a post-acute geriatric evaluation and management unit.

OBJECTIVE: To compare the Cumulative Illness Rating Scale (CIRS) and the Nursing Severity Index (NSI) as independent predictors of discharge outcome from a post-acute GEM unit and to define a multivariate model for predicting the same outcome. DESIGN: Retrospective chart review for the entire sample. The sample was split into two cohorts, a derivation cohort (n = 298) and a validation cohort (n = 154). SETTING: A 20-bed, post-acute GEM unit in a nonproprietary skilled nursing facility. PARTICIPANTS: All 452 patients admitted to the GEM from the unit's inception in December 1994 until January 1998. MEASUREMENT: Demographics, CIRS, NSI, functional status, and social support variables were measured using data available on admission to the GEM unit. The discharge outcome was dichotomized as return to the community or not. RESULTS: A total of 99.7% of the individuals in the derivation cohort were living in the community before the index hospitalization; 75.8% of patients in the derivation cohort returned to the community. The NSI, individual "severe" items from the CIRS, age, and social support were in the final logistic regression model fitted to the derivation cohort. A total of 87.7% of the observed discharge outcomes were predicted when the model was applied to the validation cohort and the calculated probability of return to the community. CONCLUSIONS: Variables for severity of illness, function, social support, and age combined into a logistic regression equation that predicted more than 80% of the dichotomized discharge outcome in the derivation cohort. The proportion of discharge outcomes that were predicted with the validation cohort remained high at 87.7%. The NSI and CIRS were each important to a model that is anticipated to refine the selection of geriatric patients for post-acute services.

Antimicrobial prescribing in long-term care facilities: prospective evaluation of potential antimicrobial use and cost indicators.

BACKGROUND: Few studies exist regarding methods of monitoring antimicrobial prescribing in the long-term care setting. METHODS: Data were collected monthly in 4 long-term care facilities (LTCFs) for 20 to 26 months. The data included incidence (No. of antimicrobial courses started per 1000 resident care days) of antimicrobial use, antimicrobial utilization ratio (ratio of the number of antimicrobial-days to the number of resident care days), cost of antimicrobial-day, and cost of therapy per resident care day. In one facility, physician-specific data were also collected. RESULTS: Seasonal variation in the incidence of antimicrobial use was identified, with the highest rates occurring in the winter months. Significant differences in the mean incidence of antimicrobial use, mean antimicrobial utilization ratio, mean cost per antimicrobial-day, and mean cost per resident care day were identified among the 4 LTCFs during the study period. A significant correlation existed between incidence of antimicrobial use or antimicrobial utilization ratio and the overall infection rate or site-specific rates when the data from all 4 LTCFs were aggregated for analysis. Monthly variation in cost per antimicrobial-day was best explained by the monthly variation in prescribing of high-cost (>$15 per day) agents. With these same parameters for use and cost, considerable variation in prescribing and cost of therapy was noted among 7 physicians in the same facility. CONCLUSIONS: The parameters evaluated detected significant differences in prescribing and cost of antimicrobials among 4 LTCFs. If these findings are verified in larger studies, these parameters may be useful for monitoring trends in prescribing and for interfacility comparisons after adjustment for case-mix differences.

Validation and application of the pneumonia prognosis index to nursing home residents with pneumonia.

OBJECTIVES: To evaluate the predictability of a pneumonia prognosis index in nursing home residents with pneumonia and to use the index to account for acute severity of pneumonia before comparing the short-term outcome of residents with pneumonia treated with intravenous antibiotic therapy in two different settings: an inpatient geriatrics unit and a nursing home DESIGN: A retrospective chart review of 158 episodes of nursing home-acquired pneumonia treated initially with intravenous antibiotics; 100 episodes were treated in an inpatient acute geriatrics service (AGS), and 58 were treated completely in a nursing home (Nursing Home group) SETTING: The AGS is a 20-bed unit within a 400-bed, public, university-affiliated hospital. The Nursing Home group consisted of residents of two nonproprietary nursing homes. PARTICIPANTS: Nursing home residents with radiographically proven pneumonia who had at least one of the following signs/symptoms: cough, fever, purulent sputum, respiratory rate > or = 25 per minute, localized auscultatory findings, or pleuritic pain. MEASUREMENTS: The pneumonia prognosis index was calculated for each resident at the time of diagnosis of pneumonia; the index has been validated as a predictor of hospital outcome in patients with community-acquired pneumonia and is also considered a measure of acute severity of pneumonia. Status (alive or dead) of each resident at 30 days after diagnosis was the major dependent variable RESULTS: Mean (+/-SD) duration of antibiotic therapy for the Nursing Home group (10.7+/-4.5 days) was not significantly different from that of the AGS group (9.6+/-3.4 days; P = .26). The pneumonia prognosis index stratified the 158 episodes of pneumonia into low- and high-risk groups for 30-day mortality; the mortality rates in each risk strata were not significantly different from those reported in the original derivation and validation studies of the index. In addition, the distribution of episodes among the risk strata of the index was not significantly different for the two study groups, which was an indication that the two groups were similar in terms of acute severity of pneumonia. Thirty-day mortality was not significantly different between the two groups: AGS, 21% and Nursing Home, 24.1% (P = .66). CONCLUSION: The pneumonia prognosis index seems to have the same capability for predicting the outcome in nursing home residents with pneumonia as in residents with community-acquired pneumonia. The index is also a measure of acute pneumonia severity. Nursing home residents with pneumonia, even those who are most acutely ill, can be treated successfully with intravenous therapy in the nursing home; their 30-day mortality was no different than that of those with the same acute severity of illness who were admitted to a hospital for treatment.

Laboratory surveillance method for nosocomial Clostridium difficile diarrhea.

BACKGROUND: Clostridium difficile is the most common infectious cause of endemic nosocomial diarrhea, but traditional surveillance methods for this infection can be time-consuming. The purpose of this article is to (1) describe a laboratory surveillance method for nosocomial diarrhea and nosocomial Clostridium difficile diarrhea (CDD) that does not require chart review and (2) describe some of the epidemiology of these infections at a university-affiliated, public hospital by using this surveillance method. METHODS: The main assumption underlying the surveillance method is that all patients with nosocomial diarrhea have a C. difficile stool toxin assay performed. On the basis of this assumption, the frequency of testing stool samples for toxin is considered a surrogate for the occurrence of nosocomial diarrhea; it is also assumed that the results of the stool toxin assay distinguish between those with (positive assay) and without (negative assay) CDD. During the study period (January 1, 1993, to August 30, 1996) surveillance for nosocomial CDD was performed by monitoring results of C. difficile stool toxin assays done with the Cytoclone A and B enzyme immunoassay. Each month a list of results of all assays performed was reviewed and patients were excluded on the basis of the following criteria. First, patients with assays done within the first 4 days of admission were assumed to have community-acquired diarrhea and excluded. Among patients with assays done > 4 days after admission, patients with two or more assays done within a 7-day period were counted only once; repeated assays (positive or negative) in the 14 days after an initial positive assay (indicating nosocomial CDD) were excluded, but assays done more than 14 days after a positive or a negative assay were counted separately (representing a relapse or new episode of diarrhea). Patients remaining on the list after all the exclusion criteria were applied represented those with nosocomial diarrhea. RESULTS: The mean (+/- SD) frequency of episodes of nosocomial diarrhea per month for each study year (1993, 1994, 1995, and first 8 months of 1996) was 52.6 +/- 16.2, 51.4 +/- 10.5, 49.2 +/- 9.3, 57.8 +/- 11.6, respectively (p = 0.48 by ANOVA); the mean frequency of nosocomial diarrhea per 1000 admissions per month was 48.4 +/- 14.5, 47.7 +/- 10.9, 44.0 +/- 9.6, and 51.6 +/- 9.3, respectively (p = 0.52); and the mean frequency of nosocomial CDD episodes per 100 episodes of nosocomial diarrhea was 24.7 +/- 8.5, 18.9 +/- 4.8, 17.4 +/- 5.7, and 12.2 +/- 7.2, respectively (p = 0.003). The median time (days) after admission to the onset of nosocomial CDD (first positive assay) for each study year was 14.5, 13.0, 12.0, and 13.0, respectively. CONCLUSIONS: Although not all of the underlying assumptions of the method have been verified, the similarity of the findings in the present study to those of previously published studies of nosocomial CDD suggests that the method is valid. Alternatives to traditional methods of performing nosocomial infection surveillance need to be developed so that infection control practitioners can focus more of their efforts on prevention activities.

Derivation and validation of a pulmonary tuberculosis prediction model.

OBJECTIVE: To describe the derivation and validation of a pulmonary tuberculosis (TB) prediction model that would enable early discontinuation of unnecessary respiratory isolation. DESIGN: Patients placed in isolation for suspected pulmonary TB were studied retrospectively (derivation cohort) and prospectively (validation cohort). Independent predictors of pulmonary TB in the derivation cohort (January 1992-March 1994) were identified by retrospective analysis. Predictors in the model were assigned weights on the basis of the results of the multivariate analysis in order to quantitate the risk of TB in an individual patient. The prospective validation consisted of application of the model to patients placed in isolation during the period April 1994 to June 1995. The predictability of the model in the derivation and validation cohorts was evaluated using receiver operating characteristics (ROC), curve analysis, and calculation of the area under the ROC curve (AUC). SETTING: A university-affiliated, urban, public hospital with a large population of prison inmates and patients with human immunodeficiency virus infection. INTERVENTIONS: Prospective application of the prediction model to patients placed in isolation during the validation period. RESULTS: Four factors were found to be independent predictors of pulmonary TB among 296 isolation episodes in the derivation cohort; positive acid-fast sputum smear (odds ratio [OR], 5.8; 95% confidence interval [CI95], 3.0-11.0; weight = 3 points), localized chest radiograph findings (OR, 2.5; CI95, 1.3-4.9; weight = 2 points), residence in a correctional facility (OR, 2.3; CI95, 1.2-4.4; weight = 2 points), and history of weight loss (OR, 1.8; CI95, 1.0-3.2; weight = 1 points). Infection control practitioners applied the model prospectively to 220 isolation episodes. The mean (+/-SE) AUCs of the ROC curve for the derivation and validation cohorts were not significantly different (.86 +/- .04 vs .86 +/- .07; P = .90). There was a significant decline in the mean duration of isolation from the onset of an automatic TB isolation policy in August 1992 to the end of the study (P = .045 by analysis of variance). CONCLUSIONS: A pulmonary TB prediction model was derived and validated prospectively in a hospital with a moderately high prevalence of TB. The model quantitated the risk of TB in an individual patient and aided infection control practitioners and primary-care physicians in their decisions to discontinue isolation during the validation period. Utilization of the model was responsible, in part, for a decrease in the mean duration of isolation during the study period. Although the model may not have general applicability due to the uniqueness of the patient population studied, this study illustrates how prediction models can be developed and used effectively to deal with a clinical problem.

Relationships between periodontal disease and bacterial pneumonia.

Bacterial pneumonia is a prevalent and costly infection that is a significant cause of morbidity and mortality in patients of all ages. The continuing emergence of antibiotic-resistant bacteria (e.g., penicillin-resistant pneumococci) suggests that bacterial pneumonia will assume increasing importance in the coming years. Thus, knowledge of the pathogenesis of, and risk factors for, bacterial pneumonia is critical to the development of strategies for prevention and treatment of these infections. Bacterial pneumonia in adults is the result of aspiration of oropharyngeal flora into the lower respiratory tract and failure of host defense mechanisms to eliminate the contaminating bacteria, which multiply in the lung and cause infection. It is recognized that community-acquired pneumonia and lung abscesses can be the result of infection by anaerobic bacteria; dental plaque would seem to be a logical source of these bacteria, especially in patients with periodontal disease. It is also possible that patients with high risk for pneumonia, such as hospitalized patients and nursing home residents, are likely to pay less attention to personal hygiene than healthy patients. One important dimension of this personal neglect may be diminished attention to oral hygiene. Poor oral hygiene and periodontal disease may promote oropharyngeal colonization by potential respiratory pathogens (PRPs) including Enterobacteriaceae (Klebsiella pneumoniae, Escherichia coli, Enterobacter species, etc.), Pseudomonas aeruginosa, and Staphylococcus aureus. This paper provides the rationale for the development of this hypothesis especially as it pertains to mechanically ventilated intensive care unit patients and nursing home residents, two patient groups with a high risk for bacterial pneumonia.

Measuring antibiotic use in a long-term care facility.

BACKGROUND: In the long-term care facility setting, there is little information about correlation of antibiotic use with care delivered or with the occurrence of fever or use of Foley catheters. The objectives of this study were to compare various measures of quantitating antibiotic use and to correlate these measures with febrile morbidity and Foley catheter use in a hospital-based, long-term care facility. METHODS: This was a prospective study in which the number of residents with fever (rectal temperature of 100.5 degrees F or greater) or a Foley catheter was documented daily. Antibiotic use was measured in several ways; incidence (courses per 100 resident care days), proportion of resident care days that were antibiotic days, the number of antibiotic courses per month, and the number of residents treated per month. RESULTS: Between January and December 1989, 111 (71%) of 156 residents were prescribed 263 antibiotic courses. Incidence of antibiotic use was 0.61 courses per 100 resident care days. On average only about 5% of resident care days per month were associated with antibiotic use, whereas an average of 18 residents per month received antibiotic therapy. Trimethoprim/sulfa and ciprofloxacin together accounted for 55% of the courses prescribed. No significant correlations were found between any antibiotic use measure and febrile days or Foley catheter days each month. CONCLUSIONS: In the long-term care facility setting, monitoring the number of residents treated with antibiotics per month is a more practical and useful measure of use than measurement of resident care days on antibiotics per month.