Women’s
Health Distance Journal Club 2/12/2014
Pamela
Downey, PT, DPT, WCS, BCB-PMD
Esther
Levy, SPT
Purpose:
Examine the inter-rater reliability and criterion-related
validity of a scale developed to quantify pelvic floor muscle (PFM)
coordination through observational assessment.
Study
Design: Descriptive study.
Participants:
20 women between 23-56 years of age (mean age 40 years) voluntarily responded
to advertisements at the Mayo Clinic in Rochester, Minnesota to participate in
the study. Both women without and with potential pelvic floor disorders served
as subjects. Mean BMI was 27.2, and median parity was 1.5 (range 0-5), with
median values of .5 vaginal deliveries (range 0-4) and median value of 0
Cesarean deliveries (range 0-3).
Inclusion
Criteria: Proficiency in the English language and ability to ambulate
independently.
Exclusion
Criteria: Presence of a progressive or non-progressive neuromuscular disease,
history of radiation therapy to the pelvis, pelvic reconstructive surgery,
complete uterine eversion, prior physical therapy interventions for pelvic
floor dysfunction, and/or sexual abuse for which one had not sought counseling.
Pelvic
Floor Muscle Coordination Scale (PFMCS) contained five separate scoring systems:
·
Respiration:
Investigators observed both the abdominal cavity/chest wall patterns and the
pelvic floor during inspiration. During inspiration, as the diaphragm contracts
and the abdominal wall expands, the PFM eccentrically lengthen and the perineum
moves caudally. This component assessed involuntary relaxation of the PFM
during respiration, and was scored the following way:
o
0-consistent
diaphragm and PFM expansion during inspiration over a 30-second time period.
o
1-inconsistent
diaphragm and pelvic floor expansion.
o
2-absence
of diaphragmatic breathing and/or PFM expansion, and/or use of accessory
muscles during respiration.
·
Pelvic
Floor Muscle Contraction: Perineal elevation (cephalic movement) of the vulva,
perineum, and the anus during voluntary contraction of the PFM. It was scored
in the following way:
o
0-indicates
the presence of cranial movement of the perineum during the first attempted PFM
contraction.
o
1-cranial
movement only during the second attempted PFM contraction.
o
2-Valsalva-type
maneuver during the attempted contraction, or no voluntary contraction was
observed.
·
Extrapelvic
Muscle Activity During Contraction: contraction of muscles other than the
pelvic floor during a voluntary PFM contraction.
o
0-absence
of extrapelvic muscle activity during the PFM contraction.
o
1-co-contraction
of 1 accessory muscle, either unilateral or bilateral, was observed during PFM
contraction.
o
2-co-contraction
of 2 or more accessory muscles was observed.
·
Pelvic
Floor Muscle Expansion: perineal descent, or caudal movement of the vulva,
perineum, and anus, during relaxation of the pelvic floor.
o
0-caudal
movement observed during the subject’s first attempt at relaxation of the PFM
following verbal cues.
o
1-caudal
movement observed only on the second attempt following verbal cues.
o
2-no
perineal descent observed and PFM expansion is considered absent.
·
Cough:
No perineal descent should be present during a cough. Cephalic movement or
involuntary contraction of PFM may also precede a cough.
o
0-Neutral
or cephalic movement of the PFM during the first cough.
o
1-Neutral
or cephalic movement of the PFM during the second cough only.
o
2-Perineum
descends with coughing during both attempts.
·
PFDI-20
questionnaire—served as the criterion standard for this study.
Standardized
Procedures: Before testing, each participant gave written consent and filled
out the PFDI-20 Questionnaire. Additionally, they answered a standard
questionnaire regarding medications used in the 6 months prior to enrollment,
surgical history, birth history, and prior treatment of symptoms by a physical
therapist (to determine inclusion in the study). One investigator educated the
participants about the pelvic floor musculature and function, as well as
potential PFM dysfunctions. After participants were educated, they disrobed
below the waist and positioned themselves in supine with hips flexed/abducted
and feet supported. At this time, 4 other investigators entered the room. A
total of 5 investigators participated in this study—1 physical therapist who
specialized in women’s health, and 4 student P.T.’s. 1 investigator was placed
on each side of the subject to support each knee, and the remaining 3
investigators stood at the foot of the table. All 5 investigators rated each
participant on their ability to coordinate their pelvic floor musculature.
Statistical
Analysis: Use descriptive statistics. Inter-rater reliability for the PFMCS
total score and each subscale score assessed with intra-class correlation
coefficient (ICC). Regression analysis used to correlate the PFMCS total score
and the PFDI-20 scores. Only scores from the primary author were used in the
analysis. Statistical significance classified as α=.05.
Results:
Most women performed a PFM contraction correctly, but the majority demonstrated
perineal descent during a cough. Few women were able to contract their PFM
without extrapelvic muscle activity, and few were able to demonstrate PFM
expansion.
·
PFDI-20
scores were positively skewed; 5 participants had a score of 0, and scores
ranged from 0-158 with a median score of 12.0. The subscale scores were also
positively skewed in a similar fashion.
·
Total
PFMCS scores ranged 0-8, median score 5.
o
Frequency
of PFM contraction: median score 0
o
Extrapelvic
muscle activity: median score 1
o
PFM
expansion: median score 0
o
Respiration:
median score 1
o
Cough:
median score 2
·
Inter-rater
reliability for PFMCS total score: ICC=.792 (good reliability)
o
PFMCS
Subscale: ICC=.812 (good reliability)
o
PFM
Expansion Subscale: ICC=.798 (good reliability)
o
Extrapelvic
Muscle Activation Subscale: ICC=.564 (moderate reliability)
o
Respiration
Subscale: ICC=.603 (moderate reliability)
o
Cough
Subscale: ICC=.642 (moderate reliability)
·
Total
score on the PFMCS was not significantly associated with the PFDI-20 total
score or with the CRAD-8 subscale. However, total scores on the PFMCS were
associated with the POPDI-6 subscale (p=.024) and UDI-6 subscale (p=.046).
Limitations:
·
Small
sample size
·
Teaching/learning
effect (participants received education prior to the exam, and were also given
verbal cues during the exam)
·
Use
of 4 student physical therapists without expertise in women’s health may have
affected the level of inter-rater reliability. If the co-raters were all
physical therapists with women’s health experience, inter-rater reliability may
have been higher.
·
Having
5 examiners present at the time of the examination may have affected the
results:
o
Visual
perspectives of each tester relative to the subject differed
o
Only
standardized cues were provided by 1 tester, whether the subject needed a cue
or not.
·
Limitations
in the subscales (extrapelvic activity, respiration, cough)—required testers to
observe multiple areas of the body simultaneously. This may have contributed to
low agreement among the investigators.
·
Scoring
criteria for the cough subscale needs to be more clearly defined. The authors
recommend this subscale to state, “Ventral/cranial movement of perineum
observed and sustained during voluntary cough” during first and second trials.
·
No
standard approach for interpreting reliability coefficients.
·
Study
participants did not likely represent patients who would seek physical therapy
services for symptoms of urinary, colorectal, and/or pelvic organ prolapse
symptoms. Therefore, the relationship between the PFMCS and the PFDI-20
questionnaire is likely to be negatively skewed.
·
Consideration
was not given to the resting tone of each participant’s PFM.
·
Reliability
and validity coefficients may have been stronger if subjects had greater levels
of PFM dysfunction. The results of this study cannot be generalized to women
with symptoms of pelvic floor dysfunction.
Take
Home: Based on the evidence presented in this article, the PFMCS holds promise
as an instrument that may allow clinicians to provide objective measures of PFM
coordination. The evidence for the scale’s total score, as well as PFM contraction
and PFM expansion subscales, were strong in terms of inter-rater reliability.
There is also evidence that score on the PFMCS had strong associated with
components of the PFDI-20. However, due to the extensive limitations of this
study, it is important that future studies be conducted in order to strengthen
the PFMCS validity, as well as generalize it to a wider population of people
with PFM dysfunction.
Discussion
Questions:
1.
While
this research serves as a good pilot study, how do we as clinicians and
researchers add other variables? What are other components of PFM coordination
that we could measure in order to strengthen the validity of this scale?
a.
Additional
research should be completed, e.g. multicenter randomized control study with
experienced women’s health clinicians, in order to obtain better statistics and
enhance the scale’s level of reliability/validity.
2.
It
is important that we be able to generalize the results of this study to
patients with PFM dysfunction, particularly those with PFM hypertonicity and/or
weakness that contribute to decreased support.
a.
What
are the typical dysfunction patterns that are seen in people who lack PFM
coordination?
b.
Are
there any other functional outcome measures that we might be able to correlate
with the scores obtained from the PFMCS?
3.
How
could we relate the results of the PFMCS to the functionality of G-codes?
a.
The
scoring in this scale is very distinct, e.g. “0 to 2” offering a black and
white picture in terms of a person’s level of PFM coordination.
b.
Is
this scale sensitive enough to be tested on people with PFM dysfunction?
c.
Is
it a good clinical screening tool to detect people with PFM dysfunction?
Slieker-ten Hove MCP, Pool-Goudzwaard AL, Eijkemans MJC, Steegers-Theunissen RPM , Burger CW, Vierhout ME. Face Validity and Reliability of the First Digital Assessment Scheme
of Pelvic Floor Muscle Function Conform the New Standardized Terminology of the
International Continence Society. Neurourology and Urodynamics 28:295–300
(2009)
This
author agrees that PFM contraction and identification of overflow muscle use
are reproducible and that cough test is not reproducible. They however disagree with this study on the reproducible
of the bearing down test and feel it is also not reproducible. This study did not measure respiration as it
is not officially part of the ICS standardization.
Messelink B, Benson T, Bergham B, et al. Standardization
of terminology of pelvic floor muscle function and dysfunction: report from the
pelvic floor clinical assessment group of the International Continence Society.
Neurourol Urodynam. 2005;24:374–380.
This
is the standardization document the tests are based on. The ICS and IUGA conservative management
working group is currently working on an updated standardization document with
will address these tests as well as terms for treatment. Stay tuned.
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