Abstract
Background
Pressure pain threshold (PPT) measurements require standardised verbal instructional cues to ensure that the increasing pressure is stopped at the correct time consistently. This study aimed to compare how PPT values, and their test-retest reliability were affected by different instructional cues.
Methods
At two separate sessions, two PPT measurements were taken at the anterior knee for each of four different instructional cues: the cue of the German Neuropathic Research Network instructions (‘DFNS’), the point where pressure first feels uncomfortable (‘Uncomfortable’), 3/10 on the numerical pain rating scale (‘3NPRS’), and where pain relates to an image from the pictorial-enhanced NPRS scale (‘Pictorial’). Linear mixed modeling was used to quantify any differences between pairs of instructional cues. Test-retest reliability was estimated using intraclass correlation coefficients (ICC[2,1] and ICC[2,k]).
Results
Twenty participants were recruited. The cue resulting in greatest PPT value was DFNS (394.32 kPa, 95%CI [286.32 to 543.06]), followed by Pictorial (342.49 kPa, 95%CI [248.68 to 471.68]), then Uncomfortable (311.85 kPa, 95%CI [226.43 to 429.48]), and lastly 3NPRS (289.78 kPa, 95%CI [210.41 to 399.09]). Five of six pairwise contrasts were statistically significant. Regardless of the cues, the point estimates of ICC (2,1) ranged from 0.79 to 0.89, and the ICC (2,k) values ranged from 0.88 to 0.94. No statistically significant differences were found between any pairwise contrasts of reliability indices.
Conclusion
Words matter when instructing people when to stop testing in pressure algometry. Clinicians should ensure that they use the same instructional cue when assessing pain threshold to ensure reliability.
Pressure pain threshold (PPT) measurements require standardised verbal instructional cues to ensure that the increasing pressure is stopped at the correct time consistently. This study aimed to compare how PPT values, and their test-retest reliability were affected by different instructional cues.
Methods
At two separate sessions, two PPT measurements were taken at the anterior knee for each of four different instructional cues: the cue of the German Neuropathic Research Network instructions (‘DFNS’), the point where pressure first feels uncomfortable (‘Uncomfortable’), 3/10 on the numerical pain rating scale (‘3NPRS’), and where pain relates to an image from the pictorial-enhanced NPRS scale (‘Pictorial’). Linear mixed modeling was used to quantify any differences between pairs of instructional cues. Test-retest reliability was estimated using intraclass correlation coefficients (ICC[2,1] and ICC[2,k]).
Results
Twenty participants were recruited. The cue resulting in greatest PPT value was DFNS (394.32 kPa, 95%CI [286.32 to 543.06]), followed by Pictorial (342.49 kPa, 95%CI [248.68 to 471.68]), then Uncomfortable (311.85 kPa, 95%CI [226.43 to 429.48]), and lastly 3NPRS (289.78 kPa, 95%CI [210.41 to 399.09]). Five of six pairwise contrasts were statistically significant. Regardless of the cues, the point estimates of ICC (2,1) ranged from 0.79 to 0.89, and the ICC (2,k) values ranged from 0.88 to 0.94. No statistically significant differences were found between any pairwise contrasts of reliability indices.
Conclusion
Words matter when instructing people when to stop testing in pressure algometry. Clinicians should ensure that they use the same instructional cue when assessing pain threshold to ensure reliability.
| Original language | English |
|---|---|
| Article number | 103150 |
| Journal | Musculoskeletal Science and Practice |
| Early online date | 23 Jul 2024 |
| DOIs | |
| Publication status | E-pub ahead of print - 23 Jul 2024 |