Algometry with a clothes peg compared to an electronic pressure algometer: a randomized cross-sectional study in pain patients

Table 4 Repeatability Data

Method of measurement	Repeatability coefficient	Mean of the differences	Standard deviation of the means of 1^st and 2^nd measurements	Standardised repeatability coefficient	Standardised mean of the differences
PPdt finger (kPa)¹⁾	89.7	- 1.44	96.3	0.93	- 0.01
PPdt ear (kPa)²⁾	54.2	- 10.5	72.3	0.75	- 0.15
Clothespin finger (NRS score)¹⁾	2.64	- 0.25	2.76	0.96	- 0.09
Clothespin ear (NRS score)²⁾	1.72	0.02	2.72	0.63	< 0.01

NRS = Numerical pain rating scale; kPa = kilo Pascal; PPdt = Pain pressure detection thresholds
¹⁾ Mean value of left and right middle finger
²⁾ Mean value of left and right ear lobe
Standardized values of the last two columns were calculated by dividing the values of the first two columns by the standard deviation of the middle column. Standardized values allow comparison between methods of measurement. A standardized mean of the differences close to zero indicates that data can be used to examine repeatability (i.e. knowledge of the first measurement is unlikely to alter the second measurement). A smaller standardized repeatability coefficient indicates a better repeatability (e.g. ears better than fingers). According to the British Standards Institution, it should be below 1 www.bsigroup.com.

ISSN: 1471-2474