EAL

UWL: Association With Outcomes (2009)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

The purpose of this study was to determine the risk factors and the incidence of nosocomial pneumonia in a university geriatric hospital.

Inclusion Criteria:

Patients with nosocomial pneumonia had to meet the following criteria:

Age 65 or older
New onset of pneumonia at least three days after initial admission
Chest X-ray confirming signs of pneumonia
At least two of the following clinical signs: Body temperature more than 38 degrees C, chest pain, recent onset or deterioration of clinical signs on auscultation, altered respiratory rate with tachypnea above 20 breaths per minute at risk and purulent sputum.

Controls not presenting any signs of nosocomial pneumonia or any suspicion of nosocomial pneumonia were selected.

Exclusion Criteria:

None specifically mentioned.

Description of Study Protocol:

Recruitment

Cases and controls were recruited from 11 departments in a university geriatric hospital from January 1, 1999 to April 15, 1999. They were admitted to either short-, intermediate- or long-term care facilities.

Design

Case-control study.

For each case with nosocomial pneumonia, two controls not presenting any signs or suspicion of nosocomial pneumonia were selected using a randomization table adapted to bed numbering. One of the controls was matched as closely as possible. The second control was not paired. Each control group was separately compared with cases in a "one case vs. one control" analysis; both control groups were then combined and compared with cases in a "one case vs. two controls" analysis. Each case was followed for up to 30 days to determine complication and mortality rates.

Statistical Analysis

Continuous variables were dichotomized by creating malnutrition level ranges
Multivariate analysis was performed on the factors found to be significant on univariate analyzes, and was based on characterization of a nominal variable, multiple correspondences and logistic regression model
Incidence rates were calculated with a 95% confidence interval (95% CI)
Comparison of risk factors between cases and controls was performed by a chi-square test and the results were expressed as the odds ratio (OR) and 95% CI.

Data Collection Summary:

Timing of Measurements

Each case was followed for up to 30 days to determine complication and mortality rates.

Dependent Variables

Complication and mortality rates associated with nosocomial pneumonia.

Independent Variables

BMI
Plasma albumin less than 30g per L or prealbumin 150mg per L or less
Swallowing disorders
Neurologic disease
Oxygen therapy
Chronic obstructive pulmonary disease
Heart failure
Active smoking
Antibiotic therapy during the previous month
Corticosteroid therapy
Diabetes mellitus
Dependency in activities of daily living
Pressure ulcers
Presence or absence of immunization against pneumococcus and influenza.

Control Variables

Age
Facility type.

Description of Actual Data Sample:

Initial N: 75 cases of nosocomial pneumonia, 150 controls
Attrition (final N): Same as above
Age: Nosocomial pneumonia cases average age was 87 years, with a range of 67 to 100 years; controls average age was 85 years, with a range of 65 to 100
Location: University geriatric hospital in Irvy-sur-Seine, France.

Summary of Results:

Risk Factor	Cases, percentage	Controls, percentage	Odds Ratio (95% CI)	P-value
Prior nosocomial pneumonia	38.4	10.7	4.50 (2.17 to 9.35)	<0.001
Oxygen therapy	10.7	0.7	16.15 (1.89 to 137.67)	<0.001
Malnutrition	31.4	8.6	4.81 (1.22 to 20.43)	<0.001
Heart failure	37.3	18.8	2.57 (1.38 to 4.19)	0.001 to 0.05
Antibiotic therapy during last month	54.1	26.8	3.20 (1.78 to 5.74)	<0.001
Eating dependency	37.3	24.1	1.87 (1.02 to 3.40)	0.001 to 0.05
Feeding by nasogastric tube	5.6	0.0	_________	0.001 to 0.05

Other Findings

75 cases of nosocomial pneumonia were diagnosed in 2,142 patients
The average incidence rate of nosocomial pneumonia was 3.5% (short-term facilities, 0.5%; intermediate-term facilities, 8.3%; and long-term care facilities, 5.3%)
The incidence density was 3.3 per 10,000 days of hospitalization
The complication rate was 58.1%
The most frequent complications were recurrent nosocomial pneumonia, heart and respiratory failure, phlebitis and pressure ulcers
The nosocomial pneumonia mortality rate was 12.2%
The independent risk factors of nosocomial pneumonia were a history of nosocomial pneumonia during the previous six months (OR=4.50) and oxygen therapy (OR=16.15), P<0.001
Additional risk factors were severe malnutrition, heart failure, prescription of antibiotics during the month preceding the emerging nosocomial pneumonia, eating dependency and feeding by nasogastric tube.

Author Conclusion:

The main risk factor for a nosocomial pneumonia is a history of pneumonia. Nosocomial pneumonia prevention in geriatrics should rely on early management of respiratory infections and malnutrition, surveillance of oxygen therapy and enteral feeding, rational use of antibiotics and adaptation to the patient's dependency.

Funding Source:

University/Hospital:

Charles Foix University Hospital, Ivry-sur-Seine, France; Bichat University Hospital, Paris, France

Reviewer Comments:

The study used BMI as a marker of malnutrition but did not define the actual value. There were two controls per case, but the second control was not matched. Subjects were only followed for 30 days.

Quality Criteria Checklist: Primary Research
Relevance Questions
	1.	Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)	N/A
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	Yes
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	Yes
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	N/A

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	Yes
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
2.	Was the selection of study subjects/patients free from bias?		???
	2.1.	Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?	Yes
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	???
	2.4.	Were the subjects/patients a representative sample of the relevant population?	???
3.	Were study groups comparable?		???
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	Yes
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	???
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	Yes
	3.4.	If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?	N/A
	3.5.	If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)	???
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
4.	Was method of handling withdrawals described?		Yes
	4.1.	Were follow-up methods described and the same for all groups?	Yes
	4.2.	Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)	Yes
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	Yes
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
5.	Was blinding used to prevent introduction of bias?		Yes
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	N/A
	5.2.	Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)	Yes
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	N/A
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	Yes
	5.5.	In diagnostic study, were test results blinded to patient history and other test results?	N/A
6.	Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?		Yes
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	N/A
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	Yes
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	Yes
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	N/A
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	N/A
	6.6.	Were extra or unplanned treatments described?	N/A
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	N/A
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
7.	Were outcomes clearly defined and the measurements valid and reliable?		???
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	???
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	???
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	Yes
	7.5.	Was the measurement of effect at an appropriate level of precision?	Yes
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	???
	7.7.	Were the measurements conducted consistently across groups?	Yes
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		Yes
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	Yes
	8.2.	Were correct statistical tests used and assumptions of test not violated?	Yes
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	Yes
	8.4.	Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?	N/A
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	Yes
	8.6.	Was clinical significance as well as statistical significance reported?	Yes
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	N/A
9.	Are conclusions supported by results with biases and limitations taken into consideration?		???
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	No
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes