1. Construct Validity of the Moisture Subscale of the Braden Scale©: A Secondary Analysis
Mary Pat Rapp, Tolulope Omolayo, Kilty Brown, Jing Li, Ryan Barrett, Susan Horn, Nancy Bergstrom
NIH/NINR Funding 5R01NR09680
TURN [Turning for Ulcer ReductioN] Study

2. Specific Aim
Evaluate the construct validity of the Moisture Subscale of the Braden Scale
Question
Is the moisture subscale of the Braden Scale inversely related to the frequency of wet observations, soiled observations, and brief changes daily?
Although the entire Braden scale has been validated in a number of studies, but the moisture subscale has not be validated
A tool is valid if it accurately measures what it is created to measure.
A tool’s construct is said to be valid if the tool sufficiently incorporates the abstract concept and the theoretical factors of the phenomenon being measured into the tool
Powers, Zentner, Nelson, & Bergstrom (2004) validated the mobility subscale

3. (Braden and Bergstrom; 1987)
Conceptual Framework
Braden Scale subscales (sensory perception, moisture, activity, mobility, nutrition, friction/shear) are proxy measures representing modifiable risk factors for pressure ulcers.
Moisture: degree to which skin is exposed to moisture
e.g., Urinary and fecal incontinence, perspiration, and wound/fistula drainage
The moisture construct is operationalized to reflect exposure, which varies from 1=constantly moist to 4=rarely moist. The construct is flexible enough to reflect urinary and fecal incontinence, the most common sources of moisture exposure, and to reflect other sources of exposure.
The major constructs of the Braden Scale are operationalized as subscales with mutually exclusive levels of severity. Each subscale is rated independently and is ranked according to severity from 1 to 4 except for the friction and shear subscale, which is rated from 1 to 3 and summed for a possible score of 6 to 23.3 Higher scores constitute higher level of wellness and less risk; lower scores are associated with higher risk of developing pressure ulcers.
The Braden Scale is intended to identify risk factors and give an overall assessment of risk while the severity of each risk factor is intended to direct the development of a personalized care plan.
(Braden and Bergstrom; 1987)

4. Construct Validity
Does a scale measure or correlate with the theorized scientific construct (e.g., "moisture") that it purports to measure?
Not restricted to one set of observable indicators or attributes.
Statistical methods assess for a common factor underlying different observable indicators.
Correlations are examined in relationship to variables related to the construct.
Construct validity refers to whether a scale measures or correlates with the theorized scientific construct (e.g., "moisture") that it purports to measure. A construct is not restricted to one set of observable indicators or attributes. It is common to a number of sets of indicators. Thus, "construct validity" can be evaluated by statistical methods that assess whether a common factor can be shown to exist underlying several measurements using different observable indicators. Evaluation of construct validity requires that the correlations of the measure be examined in relationship to variables that are known to be related to the construct (purportedly measured by the instrument being evaluated or for which there are theoretical grounds for expecting it to be related). For instance, the construct validity of the Braden Scale mobility subscale was validated previously by demonstrating that there was a positive relationship between the subscale score and the number of movements per day, with incremental increases in activity with higher subscale scores.

5. Design Setting: 20 U.S. nursing facilities
Participants (n = 343) at high and moderate risk were randomized into 3 groups (2, 3, or 4 hours repositioning)
Inclusion: >65yrs, absence of pressure ulcer, Braden Score moderate risk (13 – 14) or high risk (10-12), mobility score 1 -3
Braden Scores on enrollment and weekly for 3 weeks.
1 – 4 Braden Scores per participant with 884 observations
Initial assessment and enrollment done by nurse assessors
Participants recruited based on inclusion and exclusion criteria
Randomly assigned to 1 of 3 groups. Nurse assessors were blinded on the groups

6. Braden Scale Moisture Subscale1
Constantly Moist 2
Often Moist 3
Occasionally Moist 4
Rarely Moist
Degree to which skin is exposed to moisture
Skin is kept moist almost constantly by perspiration, urine, etc. Dampness is detected every time a patient is moved or turned.
Skin is often, but not always moist. Linen must be changed at least once a shift.
Skin is occasionally moist, requiring an extra linen change approximately once a day.
Skin is usually dry; linen only requires changing at routine intervals.

7. CNA Shift Documentation Record©
Certified nursing assistants (CNA) were instructed to reposition residents at specific intervals around the clock and record on a 24-hour Shift Documentation Record the date and time of each repositioning, new position after repositioning, heel protection, skin observations (e.g., skin changes such as red/dark areas, open areas or skin tears, bruising, or no changes), the condition of brief (e.g., dry, wet, or soiled), and incontinence care provided (e.g., brief change, washing, barrier cream application). To evaluate the integrity of the CNA Shift Documentation Record regarding positioning, which serves as proxy measure for continence care in this study, charge nurses recorded hourly observations of the participant’s position (right, left, back, or chair). Agreement between position recorded by the CNA and the charge nurse observation was measured. Agreement between position recording between the CNAs and the charge nurses was 80%.

8. Construct Validity Measurement
Paired Braden moisture subscale with the previous 24 hour CNA Shift Documentation Record of the count of
Wet observations
Soiled observations
Brief changes

9. Statistical Methods Spearman’s rank correlation coefficient
Relationship between moisture subscale score versus number of wet and fecal observations and brief changes
ANOVA followed by Duncan’s multiple range test
Determine significant differences among the moisture subscale score observations
Level of significance set at p < 0.05

10. Results: Sample Nursing Facility Residents N = 343 Female: 83.7%
Ages: > 65 years old
Mean age 84
Most prevalent age group was 86 – 90 (25.7%)
White 87.2%
Black 6.7%
Hispanic 3.8%
Asian 1.2%
Other 1.2%

11. Results Interrater reliability for the Braden Scale
Single measures r = 0.89 – 0.94,
Average measures r = 0.94 – 0.97
Moisture subscale scores were stable over three weeks
77% no difference
20.4% 1 point difference
2.3% differed by 2 – 3 points
Braden total score mean
Enrollment 12.8 (sd = 1.2)
Last was 10.8 (sd = 1.4)
The total Braden Scale scores on admission to the study ranged from 10 to 14 with a mean value of 12.8 (sd=1.2). The selected (last) total Braden Scale Score mean was 10.8 (sd=1.40) with the majority of observations (286 of 343 = 83.4%) at moderate to high risk for developing pressure ulcers (total Braden Scale scores of 10 to 14). (Note: occasionally the participant’s condition improved or deteriorated during the study and the Braden Scale score increased or decreased.)

12. Frequencies of wet, soiled, and brief change observations
Number of Observations
Most frequent moisture subscale score was 2 [n = 183, least was 4 ] (Often moist: Skin is often, but not always moist. Linen must be changed at least once a shift). The least was 4 n = 12. The mean for both wet observations and brief changes shows an overall decreasing trend as moisture subscale scores increase indicating less incontinence (Table 3). Mean wet observations per moisture subscale score ranged from 5.3 to 2.5, while mean brief changes ranged from 5.7 to Mean fecal (soiled) observations ranged from 1.1 to 0.4.
Braden moisture subscale score

13. Relationship of Braden moisture subscale score and wet, soiled, and brief observations
ANOVA
Wet observations (F = 8.78, p < )
Soiled observations (F = 2.02, p=0.111)
Brief Changes (F = 4.26, p < )
Correlation (rs)
Wet observations (rs = ; p < )
Soiled Observations (rs = ; p < 0.013)
Brief Changes (rs = ; p < )
ANOVA tests revealed that there were significant differences among the moisture subscale score groups when compared using the number of wet observations or the number of brief changes (F = 8.78, p < ; F = 4.26, p < , respectively).
For wet observations, Duncan’s multiple range test found that each subscale score was significantly different from the other. For brief changes, subscale scores 1, 2, and 3 were not significantly different from each other, but were significantly different from subscale score 4.
Using ANOVA, there were no significant differences among the moisture subscale score groups for soiled observations (F = 2.02, p=0.111).
There was a significant inverse correlation between moisture subscale scores and number of wet observations (rs = ; p < ) and number of soiled observations (rs = ; p < 0.013). This means that as the moisture subscale score increases the number of wet or soiled observations decreases. More wet or soiled observations were made with lower scores on the moisture subscale. Similarly, there is a borderline significant inverse relationship between moisture subscale scores and number of brief changes (rs = ; p < ). As the moisture subscale scores increase, there were fewer brief changes; more brief changes were made for participants with lower moisture subscale scores.
there is a borderline significant inverse relationship between moisture subscale scores and number of brief changes (rs = ; p < ). As the moisture subscale scores increase, there were fewer brief changes; more brief changes were made for participants with lower moisture subscale scores.

14. Discussion Moisture measurement varies by tool
Braden: Numerical severity scale, descriptive; urine, stool, perspiration
Waterlow: Lacks severity rating, urine, stool
Norton: Scale from dual incontinence to continence
MDS 2.0: Estimates weekly occurrence of bowel/bladder incontinence
MDS 3.0: Separates bowel and bladder, estimates incontinence episodes in last 7 days
The amount and length of exposure to moisture associated with skin changes leading to pressure ulcers is not fully understood. While risk assessment tools for long-term care facility residents measure moisture exposure using numerical values, most do not include descriptors of the amount of moisture nor do they account for changes in the consistency of stool.

15. Discussion
Construct validity of the Braden moisture subscale is partially supported
This study adds to the knowledge of the expected frequency of wet observations and brief changes
The relationship between the Braden moisture subscale scores and the number of either wet observations, soiled observations, or brief changes in the present study is one of the first studies associating observations of urinary and/or fecal incontinence and brief changes with scores on an observational scale. A significant inverse relationship between the moisture subscale scores and the number of wet observations and brief changes was present as would be expected. This inverse relationship, as well as the decreasing trend in the mean number of wet observations and brief changes as the subscale score increases supports the construct validity of the levels of moisture severity scored on the Braden Scale. However, the construct validity of the moisture subscale is only partially supported; it is limited by the relatively few participants who were fully continent (moisture subscale 4). Further evaluation of the subscale is warranted.

16. Limitations Participants limited to total Braden Scale scores 10 – 14.
Over representation of moisture subscales 2, 3
Observations limited to moisture or soiling

17. Implications
Further study of the construct validity of the moisture subscale is warranted
The descriptor, “linen changes” may need clarification
Wet observations 2 – 5/day are not consistent with usual care to check and/or change briefs every 2 hours
May be able to reduce care burden
Change in the interval for observing may improve quantity and quality of sleep