SCI: Pressure Ulcers (2007)

Citation:

Krause JS, Vines CL, Farley TL, Sniezek J, Coker J.  An exploratory study of pressure ulcers after spinal cord injury: realtionship to protective behaviors and risk factors. Arch Phys Med Rehabil 2001;82:107-113.

PubMed ID: 11239295
 
Study Design:
Cross-Sectional Study
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
To identify protective behaviors and risk factors associated with the development of pressure ulcers (PUs) after spinal cord injury (SCI).
Inclusion Criteria:

Particpants must have a

  • spinal cord injury
  • exhibit 3 of 4 of the following charateristics; lack of normal motor control, lack of normal sensation, lack of normal bladder function, and/or lack of normal bowel function
  • current residents of Arkansas
  • 18 years or older
  • at least 1 year post injury
  • no cognitive disability

 

Exclusion Criteria:
All persons who were ambulatory.
Description of Study Protocol:

Recruitment All participants were drawn from the Arkansas Spinal Cord Commission (ASCC) registry.

Design:  Cross-Sectional Study

Blinding used (if applicable):  not applicable

Intervention (if applicable)

ASCC registry case managers interviewed most participants at their residences during scheduled visits.  A small percentage were interviewed by telephone, while visiting ASCC offices, while being admitted to rehabilitation hospitals, or while attending clinics throughout the state.  Information came from the survey and case data maintained as part of routine registry activities. The survey measured protectivce behaviors and risk factors.  thirty conditions were included in the survey, falling within 7 major body or organ systems with the subset of items that related to skin conditions, demographics, protective behaviors, and risk factors.

Statistics

Univariate and logistic regression analyses were performed. Univariate comparisons were made between demographic and risk factors and the 3 PU outcomes variables.  Odds ratios were calculated to define the relation among the categoric predictors and the 3 outcome measures.  t-tests were calculated for continuous variables (age, age at injury, years since injury, number of cigarettes smoked per day, number of drinks consumed per week). Logistic regression was used to identify variables that were significantly associated with the PU outcomes when all variables were considered simultaneously.  5 demographic variables were used in the analyses as well as the protective behaviors and risk factors related to at least 1 PU outcome during univariate analyses. If 2 highly similar behaviors were significantly related only one was selected. If items were multilevel, they were dichotomized for ease of interpretation. ORs were calculated for each variable controlling for the effects of other variables in the equation. 

 

 

Data Collection Summary:

Timing of Measurements

Particpants were interviewed for the survey from May through November of 1995, information was obtained retrospectively from the ASCC registry

Dependent Variables

  • Current PU
  • PU during the past year
  • Hospitalization for a PU at any time since injury

Independent Variables

  • Protective behaviors to include personal characteristics that might be related indirectly to PUs (employment status, marital status, educational level, whether the participant was currently a student)
  • Health promotion behaviors (exercise, diet, healthy lifestyle, maintaining a healthy weight as a proxy for proper nutrition, frequent turning in bed, pressure releases while using wheelchair, checking skin for problem areas, using special cushions or mattresses, keeping skin dry)
  • Risk factors (alcohol or drug use, cigarette smoking, use of prescription medications, suicidal behavior, self-reported incarceration)

Control Variables

  • Gender
  • Race
  • Age at injury
  • Years since injury
  • Level of injury
Description of Actual Data Sample:

Initial N: 991 eligible cases met criteria, 650 agreed to participate in survey.

Attrition (final N): 560 after ambulatory subjects were excluded.

Age: 43.6 (range 20 to 86 years)

Ethnicity: Caucasian (76%), Black (22%), Other (2%)

Other relevant demographics: 23.7% with current PU, 40.2% with at least 1 PU within past year, 41.7% hospitalized for a PU since injury. 

57.7% were paraplegic, 74.1% had completed at least high school education, mean number of years since injury was 14.5 (median, 25 years) and 43.5% had been injured 1 to 10 years earlier.

Anthropometrics: Groups were divided into into those with a current PU, PU within the past year, and those hospitalized with a PU.

Location: All particpants resided in Arkansas

 

Summary of Results:

  

 

Variable ß

Standard

error

OR

CI

Upper

CI

Lower

Current PU

         
    Being underweight -.69 .31 2.00 1.09 3.66
    Smoked at least 100 cigarettes over a liftime .66 .29 1.93 1.10 3.42
PU in past year          
    Currently employed -.80 .40 .45* .21 .98
    Married -.60 .24 .55 .34 .88
    College degree -.99 .43 .37 .16 .86
Ever hospitalized for PU          
    Years postinjury .05 .01 1.06 1.03 1.07
    Gender (men) -.60 .27 .55 .32 .93
    Medication for spasticity .52 .22 1.68 1.09 2.59
    Ever incarcerated .78 .39 2.18 1.02 4.69

Other Findings

Being underweight [OR = 1.21], having used medications to treat pain [OR = 1.33] or spasticity [OR=1.31], having smoked at least 100 cigarettes over a lifetime [OR=1.31], and being a current smoker [OR=1.21] were associated with having a PU in the past year. Having completed a college degree [OR = 0.23], being married [OR 0.49] and being currently employed [OR = 0.54] were associated with a lower risk of having a PU in the past year.  Being underweight [OR = 1.94], history of incarceration [OR = 1.78], having attempted suicide [OR= 1.71] and reporting alcohol or drug treatment [OR= 1.65] were associated with having been hospitalized for PU since injury.

Author Conclusion:
PU's were least likely to occur among individuals who maintained a normal weight, are employed and maintain a family role, do not have a history of tobacco use, suicidal behaviors, self-reported incarcerations or alcohol or drug abuse. 
Funding Source:
University/Hospital: Crawford Research Institute
Reviewer Comments:

Limitations include self reporting of all information, no data was collected from actual examinations (with a few exceptions) which may result in the underreporting of alcohol and tobacco use and the overreporting of exercise, diet or healthy lifestyle.  The PU outcomes were categorical in nature with no data on location of the PU or on severity or grade of the PU.  There was no information on the cause of the PU or factors associated with the development of the PUs.  The independent variables were limited in number and since the data was cross-sectional in nature determination of cause could not be performed.

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? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
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.) No
  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? 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? No
  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.) ???
  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? 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? N/A
  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? ???
  6.6. Were extra or unplanned treatments described? ???
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? ???
  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? 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? ???
  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? 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? 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