SCI: Pressure Ulcers (2007)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
Not noted by author.
Inclusion Criteria:
None noted by author.
Exclusion Criteria:
None noted by author.
Description of Study Protocol:


Not described by author


Time Series with Comparison Group; groups and numbers of subjects within groups were not well defined.

Blinding used (if applicable)

Lab tests were blinded.

Intervention (if applicable):  Not applicable 

Statistical Analysis

Data were analyzed using descriptive statistics. Two tailed t-tests were used to compare various values obtained from participants to controls.  Significance was set at an alpha level of 0.05. Correlation coefficients were utilized to represent parallel or inverse trends in the data. The lymphocyte adhesion was espressed as a percentage of the unstimulated HUVEC (human umbilical vein endothelial cell) binding.  The mean percentage of the binding for the unstimulated HUVEC matrix was 0.7% for the control group and 0.2% for the participant group.

Data Collection Summary:

Timing of Measurements

NK-cell function, urine-free cortisol, serum ACTH, T-lymphocyte function was measured at 2 weeks and monthly thereafter up to one year post-injury.

Adhesion molecule levels were measured weekly for 6 weeks post debridement surgery.

It is not clear when serum albumin, serum prealbumin and serum zinc were measured.

Dependent Variables

  • T lymphocyte function
  • NK ( natural killer) -cell function
  • ACTH assay
  • Urine-free cortisol assay
  • FIM (functional independence measurement) score
  • Binding assay
  • serum prealbumin
  • serum albumin
  • Serum zinc

Independent Variables

  • Spinal cord injury

Control Variables

 None noted

Description of Actual Data Sample:

Initial N:

34 patients participated in the short term (<6 month) stress and immune function tests.

54 patients particpated in the long-term (> 6 month) study

Control group - no number was indicated

15 patients in the NK-cell function, CAM (cellular adhesion molecules) quantity and function and nutrition status testing.

Attrition (final N):

Not discussed by author


Short-term (< 6 month study) stress and immune function tests - average age 25 years.

Long-term (> 6 month) study average age 25 years

New patients with pressure ulcers average age of 40 years

Patients without ulcers served as controls (no age noted by author)

Patients in the NK-cell function, CAM quantity and function and nutrition status testing (no age noted by author)

Patients in the NK-cell function, CAM quantity and function and nutrition status testing


Not described

Other relevant demographics:

Short-term (< 6 month study) stress and immune function tests - 29 quadriplegics and paraplegics and 5 stroke patients.

Long-term (> 6 month) study - 28 quadriplegics, 21 paraplegics, 5 stroke patients

New patients with pressure ulcers - 13 quadriplegics and 18 paraplegics

Patients without ulcers served as controls (no other demographics noted by author)

Patients in the NK-cell function, CAM quantity and function and nutrition status testing - 9 quadriplegics and 6 paraplegics, 9 were ulcer free, 6 paraplegics had pressure ulcers.


  • Controls were healthy and age -matched but number was not attached

Location:  Mississippi

Summary of Results:



SCI patients

Mean ± SD

Control group

Mean ± SD

Statistical Significance of Group Difference

Serum prealbumin mg/dL

23.0 ± 1.0552

25.5 ± 0.7040


Serum albumin g/dL

 3.1 ± 0.1074

 4.2 ± 0.1179


NK-cell function (2 weeks post-injury) 21.0% 48.6% p<0.01
Urine-free corticsol (2 weeks post-injury) 162.4µg/24hr 53.6µg/24hr p<0.05
Plasma ACTH 17.0pg/ml 11.2 pg/ml p<0.01


 SCI patients without ulcers

 SCI patients with ulcers


Serum zinc µg/dL

82.0 ± 4.386 52.3 ± 4.313 p = 0.0003*

 * significance is set at an alpha level of 0.05.

Other Findings

  • T lymphocyte function demonstrated a significant decline beginning at 2 weeks post-injury diminishing from 92.5% of normal to 40.2% at 3 months postinjury, p<0.01.
  • NK-cell function was in the lower normal range by 6 months postinjury in patients receiving rehabilitation therapy (mean of 40.6%) and their T-cell function was restored to normal at this time (mean of 92%).  However at 12 months NK-cell function declined to 23.0%, p<0.05 but T cell function was maintained at 12 months in these individuals.
  • Those not receving rehabilitation had a sustained decline in NK-cell function (mean 11.8%, p<0.05) at 6 months and a mean of 11.8%, p<0.05 at 12 months post-injury. T-lymphocyte values remained at normal levels. 
  • NK-cell function was depressed in SCI patients, mean 2.0% ± 0.7 compared to controls 16.7% ± 4.8.  In SCI injury patients, those without pressure ulcers averaged higher than those with  ulcers (3.2% ± 1.1 and 0.8% ± 0.2).
  • FIM scores improved significantly from a mean of 49.7, p<0.01 prior to rehabilitation therapy to a  mean of 74.0 after treatment compared to a mean of 126 for normal healthy controls. Thoracic SCI patients had a FIM score of 79.8, p<0.01 prior to rehabilitation and improved to a mean of 97.3 following rehabilitation compared to thoracic SCI not receiving rehabiltation who maintained FIM scores of less than 50.
  • Lymphocyte adhesion molecules were less numerous on the SCI patietns compared to controls for eight of the nine markers. Granulocyte adhesion molecules were less numerous on 5 of the 7 surface markers in the SCI patients compared to the controls.
Author Conclusion:
By two weeks post injury SCI patients have decreased natural and adaptive immune responses. NK-cell function is decreased, while plasma ACTH and urine-free cortisol levels are increased. T cell function and activiation were both diminished.  During rehabilitation therapy, NK and T cell function both increased, but without rehabilitation NK levels remained depressed. If rehabilitation was stopped, NK function also decreased. In comparision with levels of spinal cord injury, cervical SCI patients had less NK and T function than thoracic SCI patients. Cellular adhesion molecules (CAM) were depressed in SCI patients. SCI patients with pressure ulcers have lower CAM levels than patients without pressure ulcers. All SCI patients had low levels of serum albumin and those SCI patients with pressure ulcers had decreased prealbumin and serum zinc levels.
Funding Source:
Reviewer Comments:
The study described several different groups which were used to study different outcome measures.  It was not clear which groups were used to measure each outcome.  In addition, the use of controls was not well described or clear to the reader. Timing of the nutritional measurements was not described. Differences between SCI and stroke patients were not described in the results.  No discussion of limitations of the study was included.
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? No
  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? No
  1.3. Were the target population and setting specified? No
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? No
  2.2. Were criteria applied equally to all study groups? ???
  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) ???
  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.) ???
  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")? Yes
4. Was method of handling withdrawals described? No
  4.1. Were follow-up methods described and the same for all groups? No
  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%.) No
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? ???
  4.4. Were reasons for withdrawals similar across groups? ???
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? Yes
5. Was blinding used to prevent introduction of bias? ???
  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? ???
  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? Yes
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? Yes
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? Yes
  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? No
  7.7. Were the measurements conducted consistently across groups? No
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? ???
  8.1. Were statistical analyses adequately described and the results reported appropriately? ???
  8.2. Were correct statistical tests used and assumptions of test not violated? ???
  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)? N/A
  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? No
  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