CI: Blood Glucose Control (2009)

Citation:

Krinsley JS and Jones RL, Cost analysis of initensive glycemic control in critically ill adult patients. Chest. 2006. 129:644-650.

PubMed ID: 16537863
 
Study Design:
Retrospective Cohort Study
Class:
B - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:
The purpose of this analysis was to determine if there was a difference in cost of care for critically ill adult medical, surgical, and cardiac patients when ICU personnel initiated a protocol to maintain patient blood glucose levels between 80 and 140 mg/dL.ICU personnel initiated a protocol to maintain patient blood glucose levels between 80 and 140 mg/dL.
Inclusion Criteria:

Database records of all consecutive admissions of critically ill adult medical, surgical, or cardiac patients.

Exclusion Criteria:
No cardiovascular surgeries were performed at the institution.
Description of Study Protocol:

Recruitment

  • Subjects were not recruited--database records of all consecutive admissions of critically ill adult medical, surgical, or cardiac patients were used for the study.

Design

  • Nonconcurrent cohort study

Blinding used (if applicable)

  • Not applicable: Investigators queried a comprehensive ICU database that was created in 1998.

Intervention (if applicable)

  • In the second cohort, ICU personnel had initiated a protocol to maintain patient blood glucose levels between 80 and 140 mg/dL.

Statistical Analysis

  • Analzed costs associated with ICU and non-ICU patient days, days of mechanical ventilation, and costs for laboratory, pharmacy, and radiology services.
  • Nonparametric univariate comparisons used Mann-Whitney rank-sum test. Categorical variables compared using X2 test. P value <0.05 indicated statistical significance.
  • Cost studies were adjusted for inflation.
Data Collection Summary:

Timing of Measurements

  • 800 baseline patients were consecutively admitted to ICU between February 23, 2002 and January 31, 2003.
  • 800 treatment patients were admitted consecutively between February 1, 2003 and January 10, 2004.

Dependent Variables

  • Length of stay (LOS) measured in 0.1-day increments
  • post-ICU LOS (measured in calendar days)
  • duration of mechanical ventilation (measured in 0.1-day increments)
  • Lab, pharmacy, and radiology costs

Independent Variables

  •  Blood glucose value (protocol for treatment group to maintain blood glucose between 80 and 140 mg/dL)

Control Variables

  • age
  • APACHE scores
  • mechanical ventilation status
Description of Actual Data Sample:

Initial N:

  • 1600 patients

Attrition (final N):

  • No attrition as this was a database study.

Age:

  • Described in a previous article: the two groups were well-matched with respect to age, gender, race, distribution of admitting diagnoses, prevalence of diabetes and APACHE II scores.

 

 Age and APACHE II Scores of Patients Grouped by Ventilation Status

Variables

Baseline

Mean (range)

Treatment

Mean (range)

p Value
Age--No ventilation at ICU admission 68 (51-79) 65 (50-77) 0.217
Age--Ventilation at ICU admission 72 (56-82) 73 (56-81) 0.981
APACHE II--No ventilation at ICU admission 12 (8-17) 12 (8-18) 0.739
APACHE II--Ventilation at ICU admission 23 (16-29) 22 (16-29) 0.511

Ethnicity:

  • Not described

Other relevant demographics: none

Anthropometrics

  • Not described

Location:

  •  Stamford Hospital, Stamford, CT
Summary of Results:

After initiation of the protocol to maintain blood glucose levels between 80 and 140 mg/dL, there was a mean adjusted cost savings per patient of $1,580. Patients with cardiac, GI, and surgical diagnosis had greates cost savings. Net deficits occurred among patients who were more severely ill--especially those with septic shock where mortality rate was 60.5% among baseline patients and 33.3% among treatment patients.

 Adjusted Net Cost Savings per Patient

Diagnosis Cost Savings Adjusted ($)
Cardiac 1,523
GI 1,987
Surgical 4,602
Respiratory (325)
Septic shock (2,890)
Other medical (1,394)

The cost savings were attributable to decreases in resource costs for imaging and laboratory costs among ventilated patients.

Resource Costs per Patient 

Variable

Baseline Group

median (IQR)

Treatment Group

median (IQR)

Significance

Total ICU patient days

4,171 (1-47)

3,586 (1-60)

13.9 % reduction

Total ICU patient hours

79,351 hours

65,688 hours

 17.2% reduction

Patient floor days before discharge

5 (3-9)

4 (2-8)

 p Value = 0.054

Lab--total group mean cost/day $1,091 (512-2,269) $795 (397-1,719) p Value < 0.001
Lab--no ventilation cost/day  $725 (364-1,290)  $573 (286-962) p Value =  0.004
Lab--ventilation cost/day  $2,032 (1,286-4,300)  $1,693 (1,008-3,052) p Value =  0.012
Pharmacy--total group mean cost/day  $475 (165-1,361)  $405 (1640-1037) p Value = 0.099*
Imaging--total group mean cost/day $1,062 (354-2,316) $848 (308-1,822) p Value = 0.003
Imaging--no ventilation mean cost/day  $657 (208-1,769  $848 (308-1,822)  p Value NS
Imaging--ventilation mean cost/day $1,707 (773-3,360) $1,348 (557-2,400) p Value = 0.004

TOTAL MEAN GROUP COST/DAY

$2,832 (1,296-5757) $2,145 (1,142-4,577) p Value < 0.001
TOTAL cost per day--no ventilation $1,715 (939-3369) $1,560 (938-2,809) NS
TOTAL cost per day--ventilation $5,483 (3,110-11,326) $4,661 (2,339-9499) p Value = 0.029

 Other Findings

 

Daily Cost of ICU
  Day 1 Day 2 Subsequent Days
Mechanical Ventilation $10,794 $4,796 $3,968
No Ventilation $ 6,667 $3,495 $3,184

Author Conclusion:
An intervention for intensive glycemic control in critically ill adult patients resulted in an annualized savings of $1,339,500 for the institution.  This is an estimated savings of $1,580 per patient due to decreases in all major categories of resource utilization.
Funding Source:
Reviewer Comments:
This article is a substantial addition to data analysis from Krinsley;s previous work in 2003 and 2004. The authors have furnished actual cost data for laboratory, pharmacy, imaging, and ventilator 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) 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) Yes
 
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? N/A
  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? Yes
  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? Yes
  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? Yes
  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? Yes
  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? N/A
  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? Yes
  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? N/A
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  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