diseases with symptoms of edema that are encountered a medical institutions vary from 
 internal diseases ( e.g. , kidney , liver , heart , and endocrine diseases ) to orthopedic 
 diseases , central nerve disease , and malignant tumors . generally , edema exceeds a 
 physiological compensatory function to an interstitial fluid and is defined as the condition 
 in which superfluous water content is gathered1 .
its pathogeny includes situations in which the water provision 
 system of the interstitial fluid becomes superfluous ; thus , the edema exceeds the power of 
 the physiological water content redistribution , water content redistribution system of the 
 interstitial fluid does not function sufficiently , and tissue fluids are not sufficiently 
 collected1 .
an edema is categorized as 
 either pitting edema2 or non - pitting 
 edema .
the origins of pitting edema include a reduction of the oncotic pressure by 
 hypoalbuminemia , a rise in the plasma hydrostatic pressure , and hyperpermeability of the 
 capillaries .
conversely , the origin of non - pitting edema is reflux difficulty in a lymph and 
 mucopolysaccharide , which causes docking deposition of protein in the stromata3 .
edema of the extremities is a somatic 
 symptom that is also observed in daily life situations .
although pitting edema is generally identified through questions , a physical examination , 
 and palpation , it is difficult to evaluate the condition of an edema quantitatively . 

although palpation is the most convenient method , palpation is semi - quantitative and lacks 
 reproducibility of a measured value .
in addition , circumferential measurement is 
 performed4,5,6,7 , and the error of a measurement region is directly reflected in the 
 error of a measured value ; and furthermore unification of a measured region is not prudent . 
 moreover , performing laterality ( measuring both sides ) and variation ( measuring twice ) is 
 meaningful because one alone measurement can not quantitatively evaluate an edema .
other 
 methods include water bath draining3 , 8 , 9 , 
 echography , computed tomography ( ct ) , magnetic resonance image ( mri ) , and lymph 
 scintigraphy10 , among other .
recently , 
 the impedance method11 has been performed 
 in the fields of obstetrics and gynecology12 . however , this evaluation method is a physical and economic burden 
 to the patient because it requires a high - priced instrument and is not easy to perform . 

therefore , the development of a novel objective evaluation method that can easily determine 
 the condition of an edema is warranted . for
the reasons , conventional assessment methods are not practical and do not allow for 
 quantitative evaluation .
therefore , it is considered the status - quo that evaluation of an 
 edema is not performed . in the case of a pitting edema , if acupressure is performed , a 
 surface imprint remains .
measuring the depth of the surface imprint is simple and , may be a 
 valuable tool for use in the clinic .
thus , the purpose of this study was to develop and 
 verify the reliability of a new practical evaluation method for pitting edema , which uses 
 the depth of the surface imprint as an indicator .
the subjects of this study were 26 inpatients ( 52 legs ; 8 men , 18 women ; average age , 85.0 
  5.9  years ) who were in a convalescent ward ( table 
 1table 1.subjects characteristics ( n = 26)age , years85.0  5.9gender , ( male / female)8/18height , cm151.2
 7.6weight ,  kg44.6  9.2bmi ,  kg / m19.4  3.4heart disease , n21central nerve disease , n15pancreopathy , n10orthopedic , n8kidney disease , n6pulmonary disease , n5bmi : body mass index .
data for age , height , weight , and bmi are presented as the mean  sd . ) .
all subjects were diagnosed with edema by physical examination and 
 palpation , and their general condition was comparatively stable .
, one leg , foot vulnerabilities , and those who were unavailable during the 
 study period .
data for age , height , weight , and bmi are presented as the mean  sd .
we sufficiently 
 explained the details of the study to the subjects , and all participants signed informed 
 consent .
the study was approved by the ethics committee of the university of nishikyushu 
 ( approval no .
, we developed a measurement instrument ( depth gauge for edema , km-212 - 003 ; 
 unique medical company , tokyo , japan ) to measure the depth of the surface imprint ( fig .
2.construction drawing of the depth gauge for edema ( left side , part 1 ; right side , 
 parts 2 , 3 ) shows a working drawing of the depth gauge for edema , which has three parts .
part 1 
 is made of a milky polyacetal - quality material , and it makes contact with the region 
 surrounding the surface imprint .
the bottom portion is a wide rotund shape . because the area 
 for measuring a surface imprint is a narrow region on a peripheral extremity , the diameter 
 of the surface imprint was postulated to be about 20  mm
; thus , the diameter of the bottom of 
 part 1 is 40  mm .
part 2 is made of an acrylic - like material that is transparent , and the tip 
 of this part makes contact with the deepest portion of a surface imprint . since it would not 
 be able to make contact if it was too big and it would be painful to patients if it was too 
 slim , we used a size of 3  mm , which was the optimal size after repeated test fabrications . 

part 3 is the gauge itself , which is attached to part 2 . in order to perform a visual 
 measurement using the depth gauge for edema
, we considered 0.5  mm as the measurement error . 
 during the measurement procedure ( fig . 3fig .
3.measurement procedure ) , part 1 is held with the thumb , third finger , and fourth finger .
then , 
 using a forefinger , part 2 is then pushed down a little more than the depth of the surface 
 imprint .
next , after the tip of part 2 gently makes contact with the deepest region of the 
 surface imprint , part 1 is pushed down until contact is made with the region of the 
 surrounding surface imprint . when pushing down part 1
one precaution during measuring is to perform the 
 process gently so that the surface imprint portion is not pushed too much by the tip of part 
 2 .
the two parts were elaborately fabricated so that the device could slide smoothly while 
 measuring and then rest at the time of the visual measurement  the pressing force becomes 
 constant .
instrument to measure the depth of the surface imprint construction drawing of the depth gauge for edema ( left side , part 1 ; right side , 
 parts 2 , 3 ) measurement procedure we instructed the subjects to sit on the edge of a chair and to lightly ground the soles of 
 their feet into the floor .
then we measured the right and left sides during a relaxed 
 condition so that muscular contraction was not initiated .
we measured during the morning , 
 which was considered the preinitiation of the examination or medical treatment .
the measured 
 region referred to in a previous study was the circumferential measuring method5 .
we pressed down for 10 sec on the back of 
 the feet in the central region , on the line that connects the first os metatarsale caput of 
 the bone and the fifth os metatarsale caput of the bone ; approximately 2  kg of compressive 
 force was used , as measured with a digital force gauge ( fg-5005 ; mother tool co. , ltd . , 

two examiners at maruyama hospital performed the edema measurements on different dates , and 
 we adopted a test - retest method to evaluate the degree of unanimity . to examine the 
 intra - rater reliability , examiner a performed the measurement a second time on the next day 
 after the patient had rested .
to examine inter - rater reliability , examiner b measured the 
 edema in the subjects after the surface imprint was restored .
examiner a had 10  years of 
 clinical experience , while examiner b had 3  years of clinical experience .
we analyzed the inter- and intra - rater reliabilities of the measured values from the edema 
 depth gauge using intraclass correlation coefficients ( icc ) . in the statistical analysis , we 
 considered the level of significance at 5% , and spss version 21 for windows ( spss inc . , 
 tokyo , japan ) was used for all analyses .
with regard to intra - rater reliability , the measured values of the depth of the surface 
 imprint of the right dorsal foot using the edema gauge were 3.01  1.37 for the first time 
 and 3.31  1.44 for the second time ; the icc was 0.91 .
the measured values of the depth of 
 the surface imprint of the left dorsal foot were 3.23  1.29 for the first time and 3.39  
 1.35 for the second time ; the icc was 0.97 ( table 
 2table 2.intra-rater reliability of measurementsmeasurementdepth of the surface imprint ( mm)iccright foot dorsalfirst time3.01  1.370.91second time3.31  1.44left foot dorsalfirst time3.23  1.290.97second time3.39  1.35data are presented as mean  sd .
icc : intraclass 
 correlation coefficient with regard to inter - rater reliability , the measured value of the depth of the surface 
 imprint of the right dorsal foot dorsal by examiner b was 3.06  1.37 ; the icc was 0.99 .
the 
 measured value of the depth of the surface imprint of the left dorsal foot by examiner b was 
 3.21  1.39 , and the icc was 0.97 ( table 
 3table 3.inter-rater reliability of measurementexaminersdepth of the surface imprint ( mm)iccright foot dorsala3.01
 1.370.99b3.06  1.37left foot dorsala3.23  1.290.97b3.21  1.39the data are presented as mean  sd .
we developed a practical evaluation method to easily measure the depth of the surface 
 imprint of an edema . as a result of verifying the intra - rater reliability of this assessment 
 technique ,
the icc was 0.91 for the right dorsal foot and 0.97 for the left dorsal foot , 
 indicating a high consistency .
since examiner a performed the second measurement on the day 
 following the first measurement , it was presumed that the measured value would change , but 
 there was high consistency between measurements .
this may be because the test subjects used 
 in this study were in comparatively stable conditions .
therefore , that suggests measurements 
 using the edema depth gauge are highly reproducible , even if we do not consider that the 
 measurement was taken the next day .
moreover , as a result of verifying the inter - rater reliability of the assessment technique , 
 the icc was 0.99 for the right foot dorsum and 0.97 for the left foot dorsum , showing a high 
 consistency .
therefore , the inter - rater reliability of the measurements using the depth 
 gauge for edema was also high .
thus , even if different examiners perform measurements , a 
 practically identical result can be derived .
this means that the assessment technique using 
 the depth gauge for edema is highly reliable .
if an edema is defined as the superfluous stagnating condition of interstitial fluid , some 
 questions arise about the quantifiable assessment technique of an edema .
additionally , it is 70% of the weight of soft tissue 
 such as skin ; alternatively , it is only about 10% of the weight of skeletal muscles13 .
therefore , the validity of a quantitative 
 evaluation of systemic interstitial fluid is unknown .
however , measuring of the depth of the 
 surface imprint is a vital and valid assessment of the peripheral region .
a circumferential measurement is an easy assessment technique to perform . according to a 
 previous study on subjects with an edema , brodovicz et al .
measured ankle joint 
 circumference7 , an 8-character 
 circumference using a tape measure , and lower leg volumetry using water displacement ; they 
 verified the inter - rater reliability of these three methods .
however , these methods measured 
 the entire body region , including all portio dura tissues ( e.g. , bone and soft tissues , 
 including muscular and tallow ) . therefore , there was no parameter that could evaluate an 
 edema using only one measurement . in medical practice
, a comparison of both sides using the 
 measurements on different dates can be performed to determine the difference between sides , 
 which can serve as an assessment of an edema .
conversely , it seems that the measured value 
 using a depth gauge for edema may evaluate the condition of an edema using only one 
 measurement .
we verified the reliability of this new assessment technique ( the depth gauge for edema ) 
 that measured the depth of the surface imprint of pitting edema .
in particular , we did not verify the validity of the amount of changes in the 
 circumference measurement or the measured depth of the surface imprint .
therefore , a future 
 study should verify the relationship of the tela subcutanea thickness measured by an echo 
 check , and the measured value of the depth of the surface imprint .
in conclusion , the depth 
 gauge we developed is a simple and reliable method for evaluating pitting edema .
 [ purpose ] to develop and verify the reliability of a new practical evaluation method for 
 pitting edema , which uses the depth of the surface imprint as an indicator . 
 [ subjects ] we 
 included 26 inpatients ( 52 legs ) . [ methods ] the subjects were diagnosed with edema , and we 
 verified the inter- and intra - rater reliabilities of the edema gauge using intraclass 
 correlation coefficients . [ results ] for the first and second measurement values and the 
 measured values between the examiners , the intraclass correlation coefficients were high . 
 
 [ conclusion ] therefore , our findings suggest that the edema gauge , which measures the 
 depth of the surface imprint , has sufficient intra- and inter - rater reliabilities . 
INTRODUCTION
SUBJECTS AND METHODS
RESULTS
DISCUSSION