CI: Body Weight and Outcomes: Mixed ICU Patients (2007)
- All adult patients hospitalized in the medical ICU from 1/1/1999 to 1/1/2000
- Patients who died or were discharged from ICU within 24 hours
Recruitment Chart review of all patients admitted to ICU and stayed >24 hours
Design: retrospective cohort
Blinding used (if applicable) n/a
Intervention (if applicable) n/a
Statistical Analysis
Continuous data presented as median and interquartile range; X2 or Fisher exact test for categorical data; used Mann-Whitney test to compare numeric data between groups; performed univariate analysis using nonparametric tests, and variables significantly associated with ICU mortality were entered into a multiple logistic regression model. A two-tailed p value of < 0.05 indicated statistical significance.
Timing of Measurements n/a
Dependent Variables
-
Length of Stay: measured in days
-
ICU mortality: measured by death
-
Time and duration of mechanical ventilation: measured in days
-
Nosocomial infections: measured as infections occurring > 48 h after admission
- Invasive procedures performed: urinary or vascular catheter placement, tracheotomy
-
Simplified Acute Physiological Score (SAPS II)
Independent Variables:
- Body Mass Index (patients considered to be obese if BMI > 27 which corresponded with upper quartile of patient BMIs)
Initial N: 813 patients (58% male gender)
Attrition (final N): n/a
Age: cohorts significantly different in age (p<0.001) by univariate analysis
- nonobese mean age 48 (34-65)
- obese mean age 58 (47-71)
Ethnicity: not described
Other relevant demographics:
- No significant differences in admission diagnoses, male gender, smoking history, immunodepression, nosocomial infections, mechanical ventilation, or duration of mechanical ventilation.between obese and non obese groups.
Anthropometrics:
Location: Twenty four bed medical ICU unit in a university hospital in France that has approximately 1000 critical care admissions per year.
Univariate Analysis
Variable |
Non obese |
Obese |
p Value |
Age |
48 (34-65) |
58 (47-71) |
<.0001 |
BMI |
22 |
30.8 |
<.0001 |
Length of Stay (d) |
3 (2-7) |
4 (2-9) |
<.024 |
SAPS II predicted mortality (% given as 95% CI) |
13% (11-15) |
18% (15-260 |
<.0001 |
ICU Mortality (%) |
13% |
32% |
<.0001 |
Multivariate Analysis
Variable | OR | 95% Confidence Interval | p value |
Age | 1.01 | 0.00 - 1.02 | 0.098 |
LOS in ICU | 1.02 | 0.99 - 1.04 | 0.11 |
SAPS II (each additional point | 1.08 | 1.07 - 1.10 | <0.0001 |
BMI > 27 | 1.83 | 1.10 - 2.86 | 0.017 |
Other Findings
University/Hospital: | Hopital Cochin Port-Royal Paris, Institut Jacques Cartier (France) |
The authors classified obesity as upper quartile of BMI. This resulted in individuals of BMI > 27 categorized as "obese". This is different from categorization used by NHLBI in the practice guidelines (BMI > 30 obese). Differences in age and severity of illness at admission may be problematic, although the authors did address these differences through multivariate analysis in contribution to mortality.
Quality Criteria Checklist: Primary Research
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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) | Yes | |
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? | Yes | |
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? | Yes | |
2.4. | Were the subjects/patients a representative sample of the relevant population? | Yes | |
3. | Were study groups comparable? | No | |
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? | No | |
3.3. | Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) | N/A | |
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? | No | |
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.) | N/A | |
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? | N/A | |
4.1. | Were follow-up methods described and the same for all groups? | N/A | |
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%.) | N/A | |
4.3. | Were all enrolled subjects/patients (in the original sample) accounted for? | N/A | |
4.4. | Were reasons for withdrawals similar across groups? | N/A | |
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? | N/A | |
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.) | N/A | |
5.3. | In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? | Yes | |
5.4. | In case control study, was case definition explicit and case ascertainment not influenced by exposure status? | N/A | |
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? | Yes | |
6.5. | Were co-interventions (e.g., ancillary treatments, other therapies) described? | Yes | |
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? | Yes | |
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? | Yes | |
7.3. | Was the period of follow-up long enough for important outcome(s) to occur? | N/A | |
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? | Yes | |
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? | N/A | |
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? | Yes | |
9.1. | Is there a discussion of findings? | Yes | |
9.2. | Are biases and study limitations identified and discussed? | Yes | |
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 | |